Three transgenic maize events(IE09S034,Shuangkang 12--5 and C0030.3.5)produced Cry1le,Cry1Ab/Cry2Aj and G10-EPSPS,Cry1Ab and EPSPS,respectively,all of which target the Asian corn borer.The oriental armyworm Mythimna s...Three transgenic maize events(IE09S034,Shuangkang 12--5 and C0030.3.5)produced Cry1le,Cry1Ab/Cry2Aj and G10-EPSPS,Cry1Ab and EPSPS,respectively,all of which target the Asian corn borer.The oriental armyworm Mythimna separata(Walker)is the secondary target.In this study,the effects of the three Bt maizes on the development and survival of armyworm were studied.The results showed that IE09S034 had insecticidal activity against 1st instar larvae,and the survival rate of armyworm fed with Bt maize for 10 days was 462%,significantly lower than that of the control.The larvae at 3rd--6th instar were more tolerant of the Bt toxin than the early instar larvae.However,Shuangkang 12-5 had good insecticidal activity against 1st-5th instar larvae.The mortality was nearly 100%when the larvae were fed with Shuangkang 12-5 before 3rd instar,and the toxin had quick acting eficacy.This event significantly ihibited the development of armyworm;that is,the larval duration of the 3rd and 4th instar larvae fed with Shuangkang 12-5 was prolonged by 4.5 and 3.0 days,respectively.The pupal weight and egg number were also significantly lower than those of the control.For C0030.3.5,it could control 1st--5th instar larvae effectively.The mortality rates were all over 50%if 1st-3rd larvae were fed with this event.The pupal weight of 4th-6th instar larvae fed with Bt maize were only 53.9,56.8 and 54.6%,respectively,compared to that of the control.The number of eggs laid was significantly less than the control.The results indicate that all three transgenic maize events exhibit the potential to provide effective control of early instar larvae of armyworm.which can be commercialized in future to control lepidoptera pests such as Asian corn borer and armyworm.展开更多
Betalain,an economically valuable water-soluble natural plant pigment,is prized for its strong antioxidant activity,making it popular as a dietary supplement and a visual marker for plant transformation.However,market...Betalain,an economically valuable water-soluble natural plant pigment,is prized for its strong antioxidant activity,making it popular as a dietary supplement and a visual marker for plant transformation.However,market demand significantly outstrips current production capacity.This study reports the development of an efficient push-and-pull multigene strategy based on polycistronic expression and metabolic flux regulation to enhance betalain biosynthesis in transgenic maize(Zea mays L.)endosperm.We engineered a novel enhanced RUBY(eRUBY)system derived from the original polycistronic RUBY construct(CYP76AD1P2ADODA1P2ADOPA5GT unit,abbreviated CDG)by introducing arogenate dehydrogenase(ADHα)to increase the L-tyrosine substrate supply.All the genes were driven by the endosperm-specific promoter.Fusion of ADHαinto a single polycistronic eRUBY construct(CDGA)produced significantly higher betanin(6.88 mg g−1 dry weight)and isobetanin(1.81 mg g−1 dry weight)levels than in CDG+A,which stacked the ADHαcassette independently with CDG.The high betalain accumulation in CDGA lines(which also exhibited higher transgene copy number)resulted in a 2.85–7.58-fold improvement in endosperm antioxidant capacity compared to WT(versus 2.48–2.80-fold in CDG+A).Importantly,transgenic plants maintained a normal phenotype.Transcriptome and metabolome analyses further indicated that metabolism of phenylalanine,alanine,aspartate,and glutamate contributes to betalain production.Hybridization with sweet corn successfully created a high-sugar eRUBY maize variety.Collectively,these results demonstrate the successful development of a novel maize germplasm with significantly enhanced nutritional value through high betalain accumulation.展开更多
Maize(Zea mays L.)is recognized as one of the most significant cereal crops worldwide,serving as a primary source of human food,animal feed,and industrial raw materials.With increasing diversification of market demand...Maize(Zea mays L.)is recognized as one of the most significant cereal crops worldwide,serving as a primary source of human food,animal feed,and industrial raw materials.With increasing diversification of market demands for specialty maize varieties,distinctive fresh produce cultivars characterized by unique textures have gained considerable popularity among consumers(Boyer and Shannon 1984).Notably,sweet maize is often referred to as the‘King of fruits and vegetables'due to its richness in polysaccharides,dietary fiber,trace elements,vitamins,linoleic acid,and other essential nutrients(Revilla et al.2021).展开更多
Maize yield is critically endangered by diseases throughout its growth cycle,posing significant risks to food security.The spatial and temporal dynamics of maize yield loss and the rate of yield loss attributable to t...Maize yield is critically endangered by diseases throughout its growth cycle,posing significant risks to food security.The spatial and temporal dynamics of maize yield loss and the rate of yield loss attributable to these threats on a regional scale have been challenging to ascertain due to scarce continuous observation data.This study compiled county-level data on maize yield and yield loss across China's six primary cropping regions over twenty years from 1999 to 2018.These include the Spring-sown area of Northern China(1-NC),the Summer-sown Huang-Huai-Hai Plain(2-HHP),the Southwest Mountain(3-SM),the Southern Hilly(4-SH),the Northwest Irrigated(5-NI),and the Qinghai-Tibet Plateau Maize Regions(6-QTP).We identified 15 major diseases affecting these regions.The annual average yield loss due to maize diseases in the regions 1-NC,2-HHP,3-SM,4-SH,5-NI,and 6-QTP were 0.40,0.58,0.12,0.05,0.04 and<0.01 million tons,respectively,and the corresponding average yield loss rate(the ratio of yield loss to total yield)in these regions was 0.63,0.90,0.65,0.63,0.44,and 0.05.The yield loss due to all diseases increased for three regions in 3-SM,4-SH and 5-NI.The yield loss rate due to diseases significantly increased in region 4-SH and 5-NI.Predominantly,maize leaf blight has become the most significant threats.In region 1-NC,maize head smut(D1)and maize leaf blight(D2)were the primary diseases.In region 2-HHP,maize leaf blight(D2),maize rust(D3),maize brown spot(D5),Curvularia leaf spot(D7),and maize virus disease(D14)were the key pathogens.Bivariate trend analysis(joint analysis of yield loss and loss rate trends)indicated that maize head smut(D1)decreased significantly in 1-NC,while in 2-HHP,six diseases showed a significant decrease in both yield loss and loss rate,namely sheath blight(D4),brown spot(D5),root rot(D11),downy mildew(D12)and virus disease(D14).By providing a long-term,national-scale perspective,this study not only supports the development of broad management strategies but also guides the creation of precise,region-specific control protocols to safeguard maize production.展开更多
Persistent overcast rain was an essential limiting factor for summer maize production,of which immediate impact was the dual pressure of waterlogging and shading.However,the mechanisms underlying independent and combi...Persistent overcast rain was an essential limiting factor for summer maize production,of which immediate impact was the dual pressure of waterlogging and shading.However,the mechanisms underlying independent and combined effects of waterlogging and shading on maize yield losses remain understudied,particularly across different growth stages.Denghai 605(DH605)was selected to be subjected shading,waterlogging,and their combined stress at the 3rd leaf stage(V3),the 6th leaf stage(V6),and tasseling stage(VT).Results showed that shading,waterlogging and their combination significantly restricted leaf area expansion,reduced leaf net photosynthetic rate(P_(n))and net assimilation rate(NAR),thereby decreasing the crop growth rate(CGR)and biomass accumulation.Additionally,compared to control,the process of lignin synthesis was inhibited under stressed treatment,resulting in diminished stem mechanical strength and impaired vascular system development,which substantially reduced assimilate remobilization efficiency to the ear and ultimate grain yield.Waterlogging and combined stresses exhibited maximum impact at the V3 stage,followed by V6 and VT stages,while shading effects were most pronounced at the VT stage,followed by V6 and V3 stages.Moreover,the compound stress exacerbated the damage brought about by a single stress.As climate change is projected to increase the frequency of multiple abiotic stress occurrences,these findings provide valuable insights for future summer maize breeding research under persistent rainfall conditions.展开更多
Anther is a key male reproductive organ that is essential for the plant life cycle,from the sporophyte to the gametophyte generation.To explore the isoform-level transcriptional landscape of developing anthers in maiz...Anther is a key male reproductive organ that is essential for the plant life cycle,from the sporophyte to the gametophyte generation.To explore the isoform-level transcriptional landscape of developing anthers in maize(Zea mays L.),we analyzed Iso-Seq data from anthers collected at 10 developmental stages,together with strand-specific RNA-seq,CAGE-seq,and PAS-seq data.Of the 152,026 high-confidence full-length isoforms identified,68.8%have not been described;these include 22,365 isoforms that originate from previously unannotated loci and 82,167 novel isoforms that originate from annotated protein-coding genes.Using our newly developed strategy to detect dynamic expression patterns of isoforms,we identify 13,899 differentially variable regions(DVRs);surprisingly,1275 genes contain more than two DVRs,revealing highly efficient utilization of limited genic regions.We identify 7876 long non-coding RNAs(lncRNAs)from 4098 loci,most of which were preferentially expressed during cell differentiation and meiosis.We also detected 371 long-range interactions involving intergenic lncRNAs(lincRNAs);interestingly,243 were lincRNA-gene ones,and the interacting genes were highly expressed in anthers,suggesting that many potential lncRNA regulators of key genes are required for anther development.This study provides valuable resources and fundamental information for studying the essential transcripts of key genes during anther development.展开更多
Flavonoids produced by legume roots act as signaling molecules that induce the expression of nod genes in symbiotic rhizobia.However,the role of flavonoids in root exudates under intercropping systems in promoting soy...Flavonoids produced by legume roots act as signaling molecules that induce the expression of nod genes in symbiotic rhizobia.However,the role of flavonoids in root exudates under intercropping systems in promoting soybean nodulation remains unclear.Two consecutive years of field experiments were conducted using maize–soybean strip intercropping with interspecific row spacings of 30 cm(MS30),45 cm(MS45),and 60 cm(MS60),along with sole cropping of soybean(SS)and maize(MM).Root interactions were manipulated using either no root barrier(NB)or a polyethylene plastic barrier(PB)to assess the relationship between flavonoids in root exudates and soybean nodulation.We found that root–root interaction between soybean and maize increased nodule number and fresh weight in intercropped soybean,with enhancement gradually increasing as interspecific distance widened.The proportion of nodules with diameters exceeding 0.4 cm was higher in intercropped soybean under NB compared to PB.Additionally,the expression of nodule-related genes-GmENOD40,Gm NIN2b,and Gm EXPB2-was up-regulated.Furthermore,compared to monocropping,isoflavone secretion by soybean roots decreased,whereas flavonoid and flavonol secretion by both maize and soybean roots increased under intercropping.The abundance of differentially secreted flavonoid metabolites in the rhizosphere of both species declined when root contact was prevented by the barrier.In soybean roots,the expression of Gm CHS8 and Gm IFS1 was up-regulated,while Gm ICHG was down-regulated under root interaction.Most flavonoid and flavonol compounds showed positive correlations with nodule diameter.Nodule number,fresh weight,and the proportion of nodules larger than 0.2 cm increased in diverse soybean genotypes treated with maize root exudates,which contributed to enhanced nitrogen fixation capacity.Therefore,maize–soybean strip intercropping,combined with optimal row spacing,enhances the positive effects of underground root interactions and improves nodulation and nitrogen fixation in intercropped soybean.展开更多
α.-Zeins,the major maize endosperm storage proteins,are transcriptionally regulated by Opaque2(O2)and prolamin-box-binding factor 1(PBF1),with Opaque11(O11)functioning upstream of them.However,whether O11 directly bi...α.-Zeins,the major maize endosperm storage proteins,are transcriptionally regulated by Opaque2(O2)and prolamin-box-binding factor 1(PBF1),with Opaque11(O11)functioning upstream of them.However,whether O11 directly binds toα-zein genes and its regulatory interactions with O2 and PBF1 remain unclear.Using the small-kernel mutant sw1,which exhibits decreased 19-kDa and increased 22-kDaα-zein,we positionally clone O11 and find it directly binds to G-box/E-box motifs.O11 activates 19-kDaα-zein transcription,stronger than PBF1 but weaker than O2.Notably,PBF1 competitively binds to an overlapping E-box/P-box motif,and represses O11-mediated transactivation.Although O11 does not physically interact with O2,it participates in the O2-centered hierarchical network to enhanceα-zein expression.sw1 o2 and sw1 pbf1 double mutants exhibit smaller,more opaque kernels with further reduced 19-kDa and 22-kDaα-zeins compared to the single mutants,suggesting distinct regulatory effects of these transcription factors on 19-kDa and 22-kDaα-zein genes.Promoter motif analysis suggests that O11,PBF1,and O2 directly regulate 19-kDaα-zein genes,while O11 indirectly controls 22-kDaα-zein genes via O2 and PBF1 modulation.These findings identify the unique and coordinated roles of O11,O2,and PBF1 in regulatingα.-zein genes and kernel development.展开更多
There is increasing interest in developing reduced-crude protein(CP)diets for broiler chickens because their commercial adoption would generate a diverse range of advantages that would enhance the sustainability of th...There is increasing interest in developing reduced-crude protein(CP)diets for broiler chickens because their commercial adoption would generate a diverse range of advantages that would enhance the sustainability of the chickenmeat industry.However,the development of reduced-CP broiler diets is proving to be not straightforward,particularly when dietary CP reductions exceed 30 g/kg.The capacity of broilers to accommodate dietary CP reductions when offered maize-based diets is superior to their counterparts offered wheat-based diets.Numerous factors could be contributing to this difference but have yet to be identified with certainty.Maize-based,reduced-CP diets characteristically support better weight gains and efficiencies of feed conversion than wheat-based diets,but this better growth performance is associated with increased fat deposition,monitored as heavier relative abdominal fat-pad weights.This is an intriguing dichotomy.Insulin is a powerful anabolic hormone in mammalian species capable of promoting fat deposition,protein accretion and growth,but the importance of insulin in avian species is usually dismissed.This is because broiler chickens are considered both hyperglycaemic and resistant to insulin.However,the likelihood is that young broiler chickens are more sensitive to insulin than is generally recognised and the anabolic properties of insulin may be contributing to the diverse responses observed between maize and wheat in the context of reduced-CP diets.Dietary CP reductions may trigger increased plasma ammonia concentrations and metabolic acidosis,but both factors can influence insulin secretion and insulin resistance.Maize has slower rates of starch digestion and glucose absorption than wheat and it has been suggested that this generates a more sustained insulin release resulting in increased weight gains and fat deposition.If so,this could be driving the differences generated by the feed grain selected as the basis of reduced-CP diets.The intention of this review is to explore this proposition because if the causal factors of the differences between maize and wheat can be identified the development and acceptance of reduced-CP broiler diets should be accelerated.展开更多
High temperature stress (HT) significantly reduces maize yield by impairing starch accumulation in kernels.However,the mechanism by which HT affects starch synthesis remains controversial-whether through reduced assim...High temperature stress (HT) significantly reduces maize yield by impairing starch accumulation in kernels.However,the mechanism by which HT affects starch synthesis remains controversial-whether through reduced assimilate supply or direct inhibition on kernel metabolism.To clarify these mechanisms,a heat-sensitive maize hybrid,Xianyu 335 (XY),was exposed to 30℃/20℃ (maximum/minimum temperature,control) and 40℃/30℃ for seven consecutive days during the seed setting stage.Synchronous pollination (SP),apical pollination (AP),and shading treatments were applied to manipulate the inherent source–sink ratio in maize plants.Results showed that apical kernel weight decreased by 11.9%under 40℃ in the SP treatment.The ^(13)C content,starch accumulation,and cell-wall invertase (CWIN) activity also declined by 15.9,36.7,and 16.4%,respectively,under HT.In the shading treatment,40℃/30℃ caused even greater reductions in^(13)C content,starch accumulation,and CWIN activity due to diminished assimilate supply.Conversely,in the AP treatment,starch content and CWIN activity increased by 22.0 and 18.5%,respectively,under 40℃/30℃,resulting in kernel weight and ^(13)C content similar to those in SP and shading treatments regardless of temperature.Consistent with apical kernels under AP,HT did not negatively affect middle kernels in either SP or shading treatments,as kernel weight and starch content remained unchanged under HT.Although all kernels were exposed to the same HT or control environment,their responses varied a lot.The impaired starch synthesis in apical kernels under HT was rescued by increasing carbon supply via AP treatment.The contrasting performance among middle kernels,apical kernels under AP,and apical kernels under SP or shading indicates that reduced carbon supply is a critical factor underlying inhibited starch accumulation.Our findings provide a theoretical basis for further understanding kernel abortion under HT.展开更多
In maize production,the development of density-tolerant and lodging-resistant varieties has made dense planting an effective strategy for achieving high and stable yields,with superior hybrids serving as a prerequisit...In maize production,the development of density-tolerant and lodging-resistant varieties has made dense planting an effective strategy for achieving high and stable yields,with superior hybrids serving as a prerequisite for successful highdensity cultivation.However,the photosynthetic mechanisms underlying improved density tolerance in maize hybrids released across different eras in China remain unclear.This study investigates 40 years of breeding progress toward enhanced photosynthetic traits under varying planting densities and elucidates the physiological and ecological bases of improved density tolerance in maize hybrids.A three-year field experiment was conducted from 2019 to 2021 to compare eight major Chinese hybrids from four decadal cohorts under three planting densities:45,000(D1),67,500(D2),and 90,000(D3)plants ha^(-1).At high density(D3),modern hybrids exhibited a more optimal canopy architecture and superior leaf photosynthetic performance compared to older hybrids,despite a slight reduction in specific leaf nitrogen.Notably,modern hybrids(2000s)were able to maintain higher net photosynthetic rates and photosynthetic nitrogen use efficiency(PNUE)at D3,resulting in the highest grain yield(GY),which was 118.47%greater than that of older hybrids(1970s).Leaf area duration after anthesis,total chlorophyll content,key photosynthetic enzyme activities,and maximum quantum efficiency of PSII photochemistry were all positively correlated with GY.Among these,PNUE showed the strongest correlation with grain yield and thus represents a key indicator for optimizing maize hybrids.Based on these findings,breeders should continue selecting hybrids under high-density and suboptimal conditions,focusing on optimizing population architecture and enhancing photosynthetic capacity while fine-tuning leaf nitrogen status to develop high-yielding,density-tolerant hybrids capable of sustaining long-term increases in maize grain yield.展开更多
The irrigation districts of northern China face issues such as water scarcity,inability to effectively utilize flood resources,and groundwater overexploitation.In view of these challenges,this study proposes a new con...The irrigation districts of northern China face issues such as water scarcity,inability to effectively utilize flood resources,and groundwater overexploitation.In view of these challenges,this study proposes a new concept of deep storage irrigation through flood resources utilization.However,whether deep storage irrigation can recharge deep soil moisture and sustain crop production still requires further study.A two-year field experiment was conducted on summer maize in the Guanzhong Plain with five soil wetting layer depths(T1:60 cm;T2:90 cm;T3:120 cm;T4:150 cm;T5:180 cm)and soil saturation moisture content as the irrigation upper limit.The results presented that the ranges of deep soil moisture recharge in the100–200 cm soil profile(SMS_(100–200))was 73.34–267.42 and 0–150.03 mm in 2021(wet season)and 2022(normal season).When the effective precipitation and irrigation exceeded 390 mm,the SMS_(100–200)began to linearly increase.The highest grain yield(GY)were observed at T2 and T3 treatments in 2021(11.44 t ha^(-1))and 2022(11.25 t ha^(-1)),respectively.The maize GY of T4 in 2021 and T5 in 2022 were only 3.9 and 5.7%lower than the maximize GY,respectively.However,the SMS_(100–200)for T4 and T5 were 2.4 and 5.0 times that of T2 and T3 treatments in 2021 and 2022,respectively.Overall,the further increase in irrigation amounts induced only a slight decrease in grain yield,but it significantly increased deep soil moisture recharge.Therefore,the deep storage irrigation breaks through the traditional idea of water-saving irrigation with limited water resources,which can be utilized as an effective alternative to address the issues of water scarcity,low flood resources utilization,and groundwater level declines in the irrigation districts of northern China.展开更多
Carbohydrate partitioning from source to sink tissues is essential for plant growth and development.However,in maize(Zea mays L.),the molecular mechanisms by which callose synthase genes regulate this process remain l...Carbohydrate partitioning from source to sink tissues is essential for plant growth and development.However,in maize(Zea mays L.),the molecular mechanisms by which callose synthase genes regulate this process remain largely unexplored.This study demonstrates that mutation of maize callose synthase12(Zm Cals12)results in increased carbohydrate accumulation in photosynthetic leaves but decreased carbohydrate content in sink tissues,leading to plant dwarfing and male sterility.Histochemical β-glucuronidase(GUS)activity assay and m RNA in situ hybridization(ISH)revealed that Zm Cals12 expression mainly occurs in the vascular transport system.Zm Cals12 loss-of-function decreased callose synthase activity and callose deposition in plasmodesmatas(PDs)and surrounding phloem cells(PCs)of the vascular bundle.The drop-and-see(DANS)assay indicated reduced PD permeability in photosynthetic cells and diminished transport competence of leaf veins in Zmcals12 mutants,resulting in decreased symplastic transport.Paraffin section analysis revealed that less-developed vascular cells(VCs)in Zmcals12 mutants likely disrupted sugar transport,contributing to the pleiotropic phenotype.Furthermore,impaired sugar transport inhibited internode development by suppressing auxin(IAA)biosynthesis and signaling in Zmcals12 mutant.These findings elucidate the mechanism by which Zm Cals12-mediated callose deposition and symplastic transport regulate maize growth and development.展开更多
Sand dust belts span approximately one-fifth of the global land surface.In these regions,dust tends to settle on vegetation surfaces,altering the observed reflectance and affecting remote sensing detections.To enhance...Sand dust belts span approximately one-fifth of the global land surface.In these regions,dust tends to settle on vegetation surfaces,altering the observed reflectance and affecting remote sensing detections.To enhance the accuracy of maize growth monitoring in dust-affected regions,this study aims to quantify the effect of sand dust retention on maize during the tasseling stage in the Kashgar Prefecture,Xinjiang Uygur Autonomous Region,China,by analyzing changes in canopy reflectance and vegetation indices.First,field sampling was conducted to measure the key canopy structure parameters and dust retention levels of maize,and laboratory spectral measurements were performed on leaf spectral properties under gradient dust retention.The measured data were then used to drive the LargE-Scale remote sensing data and image Simulation framework(LESS)model for simulating realistic maize canopy spectra across different dust levels,with validation against Sentinel-2 imagery.Second,on the basis of the simulated and satellite-derived spectra,the dust resistance of 36 common vegetation indices was systematically evaluated,and new robust dust-resistant indices were developed.The results showed that compared with dust-free maize,the canopy reflectance of dust-retained maize followed an increase–decrease–increase pattern,with critical turning points at 735 and 1325 nm.The maximum reflectance difference of–0.11755(change rate:29.002%)occurred within the 735–1325 nm range at 24 g/m^(2)dust retention,and the minimum reflectance difference of 0.04285(change rate:148.950%)was observed in the 350–735 nm range under the same dust retention level.Among the 36 vegetation indices,only the global environment monitoring index(GEMI)and the ratio of transformed chlorophyll absorption in reflectance index to optimized soil-adjusted vegetation index(TCARI/OSAVI)exhibited dust resistance,with GEMI being effective below 6 g/m^(2)and TCARI/OSAVI remaining stable across all levels(average ratio:0.970).The newly developed indices in this study,(RE3–RE2)/(NIR–RE2),(RE3–RE2)/(RE4–RE2),and(NIR–RE2)/(RE4–RE2),retained values within the predefined dust-resistant range over the full dust retention levels of 0–24 g/m^(2),thus showing a more stable dust resistance compared with the commonly used 36 vegetation indices.Specially,(RE3–RE2)/(RE4–RE2)performed the most robustly in Sentinel-2 imagery,that is,58.020%of pixels were within the dust-resistant range,and an average ratio of 0.937 was obtained for the original-spectra index.This study provides a scientific basis for crop monitoring and management in dust-affected regions.展开更多
A novel insecticidal gene crylAh was cloned from Bacillus thuringiensis isolate BT8 previously for plant genetic engineering improvement. Truncated active CrylAh toxin has a toxicity level similar to that of the full-...A novel insecticidal gene crylAh was cloned from Bacillus thuringiensis isolate BT8 previously for plant genetic engineering improvement. Truncated active CrylAh toxin has a toxicity level similar to that of the full-length CrylAh toxin. In this study, plant expression vector pMhGM harboring truncated crylAh gene was transformed into maize （Zea mays L.） immature embryos by Agrobacterium tumefaciens-mediated transformation at which maize alcohol dehydrogenase matrix attachment regions （madMARs） were incorporated on both sides of the gene expression cassette to improve gene expression. A total of 23 PCR positive events were obtained with a transformation efficiency of 5% around. Bioassay results showed that events 1-4 and 1-5 exhibited enhanced resistance to the Asian corn borer （Ostriniafurnacalis）. These two events were further confirmed by molecular analysis. Southern blot suggested that a single copy of the crylAh gene was successfully integrated into the maize genome. Western blot and ELISA showed that the foreign gene crylAh was expressed stably at high level in maize and could be inherited stably over generations. The results of a bioassay of T l-T4 transgenic maize plants indicated that the transgenic plants were highly toxic to the Asian corn borer and their resistance could be inherited stably from generation to generation. Thus, events 1-4 and 1-5 are good candidates for the breeding of insect-resistant maize.展开更多
In order to promote the research of transgenic insect-resistant maize,the target gene were transferred into maize material Hi-Ⅱ by Agrobacterium-mediated genetic transformation of maize embryos,and maize plants with ...In order to promote the research of transgenic insect-resistant maize,the target gene were transferred into maize material Hi-Ⅱ by Agrobacterium-mediated genetic transformation of maize embryos,and maize plants with CryNGc insect-resistant genes were cultured by explant infection,co-culture and differentiation screening to study the genetic expression and resistance of exogenous genes in the offspring.The results showed that the infection effect was the best when the size of young maize embryo was 1.2-1.8 mm.Ten positive transformed plants with CryNGc insect-resistant genes were successfully obtained,and the transformation efficiency was 1.428‰.展开更多
The use of genetically modified varieties tolerant to herbicides(HT varieties)and resistant to insects(Bt varieties)in combination with application of a broad-spectrum herbicide such as glyphosate could be an effectiv...The use of genetically modified varieties tolerant to herbicides(HT varieties)and resistant to insects(Bt varieties)in combination with application of a broad-spectrum herbicide such as glyphosate could be an effective option for the simultaneous control of weeds and pests in maize.Nevertheless,the possible impact of these tools on nontarget arthropods still needs to be evaluated.In a field study in central Spain,potential changes in populations of canopy-dwelling arthropods in Bt maize under different weed management options,including glyphosate application,were investigated.Canopy-dwelling arthropods were sampled by visual inspection and yellow sticky traps.The Bt variety had no effect on any group of studied arthropods,except for the expected case of corn borers—the target pests of Bt maize.Regarding the effects of herbicide regimes,the only observed difference was a lower abundance of Cicadellidae and Mymaridae on yellow sticky traps in plots not treated with pre-emergence herbicides.This effect was especially pronounced in a treatment involving two glyphosate applications.The decrease in Cicadellidae and Mymaridae populations was associated with a higher density of weeds in plots,which may have hindered colonization of the crop by leafhoppers.These differences,however,were only significant in the last year of the study.The low likelihood of the use of glyphosate-and herbicide-tolerant varieties for weed control triggering important effects on the nontarget arthropod fauna of the maize canopy is discussed.展开更多
A four-year field experiment was conducted with two cultivars and four N rate to investigate the spatiotemporal characteristics of leaf senescence in maize after silking and its response to N fertilizer rates on them,...A four-year field experiment was conducted with two cultivars and four N rate to investigate the spatiotemporal characteristics of leaf senescence in maize after silking and its response to N fertilizer rates on them,as well as to reveal the differences in post-silking chlorophyll degradation between low-N-tolerant cultivars.The results showed that the order of leaf senescence after silking in maize was lower leaf>upper leaf>ear leaf,leaf tip>middle>base.Increasing N fertilizer down-regulated the expression of ZmCLH2 and ZmPPH in the leaves at 10-30 d after silking,reducing CLH and PPH activities,thereby delaying the leaf senescence.These effects were more prominent in low-N-sensitive cultivar Xianyu 508(XY508)than in low-N-tolerant cultivar Zhenghong 311(ZH311),especially in the lower leaves and leaf tip.Under low N condition,leaf yellowing and chlorophyll degradation occurred later and slower in ZH311 than in XY508.This resulted in a higher post-silking dry matter accumulation and grain yield in ZH311,which may be one of the important physiological bases of low nitrogen tolerant cultivars.Future research should focus on developing low-N-tolerant maize cultivars with slower leaf senescence near the ear after silking.展开更多
Maize(Zea mays),which is a vital source of food,feed,and energy feedstock globally,has significant potential for higher yields.However,environmental stress conditions,including drought and salt stress,severely restric...Maize(Zea mays),which is a vital source of food,feed,and energy feedstock globally,has significant potential for higher yields.However,environmental stress conditions,including drought and salt stress,severely restrict maize plant growth and development,leading to great yield losses.Leucine-rich repeat receptor-like kinases(LRR-RLKs)function in biotic and abiotic stress responses in the model plant Arabidopsis(Arabidopsis thaliana),but their roles in abiotic stress responses in maize are not entirely understood.In this study,we determine that the LRR-RLK ZmMIK2,a homolog of the Arabidopsis LRR-RK MALE DISCOVERER 1(MDIS1)-INTERACTING RECEPTOR LIKE KINASE 2(MIK2),functions in resistance to both drought and salt stress in maize.Zmmik2 plants exhibit enhanced resistance to both stresses,whereas overexpressing ZmMIK2 confers the opposite phenotypes.Furthermore,we identify C2-DOMAIN-CONTAINING PROTEIN 1(ZmC2DP1),which interacts with the intracellular region of ZmMIK2.Notably,that region of ZmMIK2 mediates the phosphorylation of ZmC2DP1,likely by increasing its stability.Both ZmMIK2 and ZmC2DP1 are mainly expressed in roots.As with ZmMIK2,knockout of ZmC2DP1 enhances resistance to both drought and salt stress.We conclude that ZmMIK2-ZmC2DP1 acts as a negative regulatory module in maize drought-and salt-stress responses.展开更多
The application of organic fertilizers has become an increasingly popular practice in maize production to reduce thegaseous nitrogen(N) loss and soil degradation caused by inorganic fertilizers. Organic fertilizer pla...The application of organic fertilizers has become an increasingly popular practice in maize production to reduce thegaseous nitrogen(N) loss and soil degradation caused by inorganic fertilizers. Organic fertilizer plays a key rolein improving soil quality and stabilizing maize yields, but few studies have compared different substitution rates. Afield study was carried out in 2021 and 2022, based on a long-term trial initiated in 2016, which included five organicfertilizer N substitution rates with equal inputs of 200 kg N ha^(–1): 0% organic fertilizer(T1, 100% inorganic fertilizer),50.0% organic+50.0% inorganic fertilizer(T2), 37.5% organic+62.5% inorganic fertilizer(T3), 25.0% organic+75.0%inorganic fertilizer(T4), and 12.5% organic+87.5% inorganic fertilizer(T5), as well as a no fertilizer control(T6). Theresults of the two years showed that T3 and T1 had the highest grain yield and biomass, respectively, and there wasno significant difference between T1 and T3. Compared with T1, the 12.5, 25.0, 37.5, and 50.0% substitution rates in T5, T4, T3, and T2 significantly reduced total nitrogen losses(NH_(3), N_(2)O) by 8.3, 16.1, 18.7, and 27.0%, respectively.Nitrogen use efficiency(NUE) was higher in T5, T3, and T1, and there were no significant differences among them.Organic fertilizer substitution directly reduced NH_(3)volatilization and N_(2)O emission from farmland by lowering theammonium nitrogen and alkali-dissolved N contents and by increasing soil moisture. These substitution treatmentsreduced N_(2)O emissions indirectly by regulating the abundances of AOB and nirK-harboring genes by promotingsoil moisture. Specifically, the 37.5% organic fertilizer substitution reduces NH_(3)volatilization and N_(2)O emission from farmland by reducing the ammonium nitrogen and alkali-dissolved N contents and increasing moisture, which negatively regulate the abundance of AOB and nir K-harboring genes to reduce N_(2)O emissions indirectly in rainfed maize fields on the Loess Plateau of China.展开更多
基金We thank Dr.Jeannie McDonald(Ecology and Evolutionary Biology Department,Cornell University,NY,USA)very much for herlcontribution to the manuscript revision.This research was supported by the National Science and Technology Major Project,China(2016ZX08012-004-010)the Key Research and Development Project of Jiangsu Province,China(BE2017379-3).
文摘Three transgenic maize events(IE09S034,Shuangkang 12--5 and C0030.3.5)produced Cry1le,Cry1Ab/Cry2Aj and G10-EPSPS,Cry1Ab and EPSPS,respectively,all of which target the Asian corn borer.The oriental armyworm Mythimna separata(Walker)is the secondary target.In this study,the effects of the three Bt maizes on the development and survival of armyworm were studied.The results showed that IE09S034 had insecticidal activity against 1st instar larvae,and the survival rate of armyworm fed with Bt maize for 10 days was 462%,significantly lower than that of the control.The larvae at 3rd--6th instar were more tolerant of the Bt toxin than the early instar larvae.However,Shuangkang 12-5 had good insecticidal activity against 1st-5th instar larvae.The mortality was nearly 100%when the larvae were fed with Shuangkang 12-5 before 3rd instar,and the toxin had quick acting eficacy.This event significantly ihibited the development of armyworm;that is,the larval duration of the 3rd and 4th instar larvae fed with Shuangkang 12-5 was prolonged by 4.5 and 3.0 days,respectively.The pupal weight and egg number were also significantly lower than those of the control.For C0030.3.5,it could control 1st--5th instar larvae effectively.The mortality rates were all over 50%if 1st-3rd larvae were fed with this event.The pupal weight of 4th-6th instar larvae fed with Bt maize were only 53.9,56.8 and 54.6%,respectively,compared to that of the control.The number of eggs laid was significantly less than the control.The results indicate that all three transgenic maize events exhibit the potential to provide effective control of early instar larvae of armyworm.which can be commercialized in future to control lepidoptera pests such as Asian corn borer and armyworm.
基金supported by grants from the Biological Breeding-National Science and Technology Major Project(2024ZD04077)the Invigorate the Seed Industry of Guangdong Province(2024-NPY-00-044)+3 种基金the National Natural Science Foundation of China(32272120)the Guangxi Science and Technology Major Project(GKAA24206023)the National Key Research and Development Program of China(2024YFF1000800)the Guangdong Basic Research Center of Excellence for Precise Breeding of Future Crops Major Project(FCBRCE-202502,FCBRCE-202504).
文摘Betalain,an economically valuable water-soluble natural plant pigment,is prized for its strong antioxidant activity,making it popular as a dietary supplement and a visual marker for plant transformation.However,market demand significantly outstrips current production capacity.This study reports the development of an efficient push-and-pull multigene strategy based on polycistronic expression and metabolic flux regulation to enhance betalain biosynthesis in transgenic maize(Zea mays L.)endosperm.We engineered a novel enhanced RUBY(eRUBY)system derived from the original polycistronic RUBY construct(CYP76AD1P2ADODA1P2ADOPA5GT unit,abbreviated CDG)by introducing arogenate dehydrogenase(ADHα)to increase the L-tyrosine substrate supply.All the genes were driven by the endosperm-specific promoter.Fusion of ADHαinto a single polycistronic eRUBY construct(CDGA)produced significantly higher betanin(6.88 mg g−1 dry weight)and isobetanin(1.81 mg g−1 dry weight)levels than in CDG+A,which stacked the ADHαcassette independently with CDG.The high betalain accumulation in CDGA lines(which also exhibited higher transgene copy number)resulted in a 2.85–7.58-fold improvement in endosperm antioxidant capacity compared to WT(versus 2.48–2.80-fold in CDG+A).Importantly,transgenic plants maintained a normal phenotype.Transcriptome and metabolome analyses further indicated that metabolism of phenylalanine,alanine,aspartate,and glutamate contributes to betalain production.Hybridization with sweet corn successfully created a high-sugar eRUBY maize variety.Collectively,these results demonstrate the successful development of a novel maize germplasm with significantly enhanced nutritional value through high betalain accumulation.
基金supported by the Youth Research Foundation of Beijing Academy of Agriculture and Forestry Sciences,China(QNJJ202420)the Beijing Science and Technology Association Youth Lifting Project,Chinathe Beijing Municipal Rural Revitalization Agricultural Science and Technology Development Project,China(NY2401020224)。
文摘Maize(Zea mays L.)is recognized as one of the most significant cereal crops worldwide,serving as a primary source of human food,animal feed,and industrial raw materials.With increasing diversification of market demands for specialty maize varieties,distinctive fresh produce cultivars characterized by unique textures have gained considerable popularity among consumers(Boyer and Shannon 1984).Notably,sweet maize is often referred to as the‘King of fruits and vegetables'due to its richness in polysaccharides,dietary fiber,trace elements,vitamins,linoleic acid,and other essential nutrients(Revilla et al.2021).
基金supported by the National Key Research and Development Program of China,China(2022YFF1301801)Agricultural scientific and technological innovation project of Shandong Academy of Agricultural Sciences,China(333 Project)(06202214442066)+1 种基金Beijing Natural Science Foundation,China(5232018)Technology Innovation Project of Shandong Academy of Agricultural Sciences,China(06202214442062).
文摘Maize yield is critically endangered by diseases throughout its growth cycle,posing significant risks to food security.The spatial and temporal dynamics of maize yield loss and the rate of yield loss attributable to these threats on a regional scale have been challenging to ascertain due to scarce continuous observation data.This study compiled county-level data on maize yield and yield loss across China's six primary cropping regions over twenty years from 1999 to 2018.These include the Spring-sown area of Northern China(1-NC),the Summer-sown Huang-Huai-Hai Plain(2-HHP),the Southwest Mountain(3-SM),the Southern Hilly(4-SH),the Northwest Irrigated(5-NI),and the Qinghai-Tibet Plateau Maize Regions(6-QTP).We identified 15 major diseases affecting these regions.The annual average yield loss due to maize diseases in the regions 1-NC,2-HHP,3-SM,4-SH,5-NI,and 6-QTP were 0.40,0.58,0.12,0.05,0.04 and<0.01 million tons,respectively,and the corresponding average yield loss rate(the ratio of yield loss to total yield)in these regions was 0.63,0.90,0.65,0.63,0.44,and 0.05.The yield loss due to all diseases increased for three regions in 3-SM,4-SH and 5-NI.The yield loss rate due to diseases significantly increased in region 4-SH and 5-NI.Predominantly,maize leaf blight has become the most significant threats.In region 1-NC,maize head smut(D1)and maize leaf blight(D2)were the primary diseases.In region 2-HHP,maize leaf blight(D2),maize rust(D3),maize brown spot(D5),Curvularia leaf spot(D7),and maize virus disease(D14)were the key pathogens.Bivariate trend analysis(joint analysis of yield loss and loss rate trends)indicated that maize head smut(D1)decreased significantly in 1-NC,while in 2-HHP,six diseases showed a significant decrease in both yield loss and loss rate,namely sheath blight(D4),brown spot(D5),root rot(D11),downy mildew(D12)and virus disease(D14).By providing a long-term,national-scale perspective,this study not only supports the development of broad management strategies but also guides the creation of precise,region-specific control protocols to safeguard maize production.
基金supported by the University Youth Innovation Science and Technology Support Program of Shandong Province,China(2021KJ073)the Postdoctoral Innovation Program of Shandong Province,China(202003039)+2 种基金the China Agriculture Research System(CARS-02-21)the State Key Laboratory of North China Crop Improvement and Regulation(NCCIR2023KF-8)the Key R&D Program of Shandong Province,China(2023TZXD08603)。
文摘Persistent overcast rain was an essential limiting factor for summer maize production,of which immediate impact was the dual pressure of waterlogging and shading.However,the mechanisms underlying independent and combined effects of waterlogging and shading on maize yield losses remain understudied,particularly across different growth stages.Denghai 605(DH605)was selected to be subjected shading,waterlogging,and their combined stress at the 3rd leaf stage(V3),the 6th leaf stage(V6),and tasseling stage(VT).Results showed that shading,waterlogging and their combination significantly restricted leaf area expansion,reduced leaf net photosynthetic rate(P_(n))and net assimilation rate(NAR),thereby decreasing the crop growth rate(CGR)and biomass accumulation.Additionally,compared to control,the process of lignin synthesis was inhibited under stressed treatment,resulting in diminished stem mechanical strength and impaired vascular system development,which substantially reduced assimilate remobilization efficiency to the ear and ultimate grain yield.Waterlogging and combined stresses exhibited maximum impact at the V3 stage,followed by V6 and VT stages,while shading effects were most pronounced at the VT stage,followed by V6 and V3 stages.Moreover,the compound stress exacerbated the damage brought about by a single stress.As climate change is projected to increase the frequency of multiple abiotic stress occurrences,these findings provide valuable insights for future summer maize breeding research under persistent rainfall conditions.
基金supported by the Excellent Young Scientists Fund(Category B)(32422063)the National Key Research and Development Program of China(2022YFF1003500)the Zhengzhou University Qiushi Postdoctoral Research Funding Program.For open access,the authors have applied for a Creative Commons Attribution(CC BY)license for any Author Accepted Manuscript version arising from this submission.
文摘Anther is a key male reproductive organ that is essential for the plant life cycle,from the sporophyte to the gametophyte generation.To explore the isoform-level transcriptional landscape of developing anthers in maize(Zea mays L.),we analyzed Iso-Seq data from anthers collected at 10 developmental stages,together with strand-specific RNA-seq,CAGE-seq,and PAS-seq data.Of the 152,026 high-confidence full-length isoforms identified,68.8%have not been described;these include 22,365 isoforms that originate from previously unannotated loci and 82,167 novel isoforms that originate from annotated protein-coding genes.Using our newly developed strategy to detect dynamic expression patterns of isoforms,we identify 13,899 differentially variable regions(DVRs);surprisingly,1275 genes contain more than two DVRs,revealing highly efficient utilization of limited genic regions.We identify 7876 long non-coding RNAs(lncRNAs)from 4098 loci,most of which were preferentially expressed during cell differentiation and meiosis.We also detected 371 long-range interactions involving intergenic lncRNAs(lincRNAs);interestingly,243 were lincRNA-gene ones,and the interacting genes were highly expressed in anthers,suggesting that many potential lncRNA regulators of key genes are required for anther development.This study provides valuable resources and fundamental information for studying the essential transcripts of key genes during anther development.
基金funded by the National Key Research and Development Program of China(2021YFF1000500)the National Natural Science Foundation of China(32372231)(3187101212)the earmarked fund for China Agriculture Research System(CARS-04-PS21)。
文摘Flavonoids produced by legume roots act as signaling molecules that induce the expression of nod genes in symbiotic rhizobia.However,the role of flavonoids in root exudates under intercropping systems in promoting soybean nodulation remains unclear.Two consecutive years of field experiments were conducted using maize–soybean strip intercropping with interspecific row spacings of 30 cm(MS30),45 cm(MS45),and 60 cm(MS60),along with sole cropping of soybean(SS)and maize(MM).Root interactions were manipulated using either no root barrier(NB)or a polyethylene plastic barrier(PB)to assess the relationship between flavonoids in root exudates and soybean nodulation.We found that root–root interaction between soybean and maize increased nodule number and fresh weight in intercropped soybean,with enhancement gradually increasing as interspecific distance widened.The proportion of nodules with diameters exceeding 0.4 cm was higher in intercropped soybean under NB compared to PB.Additionally,the expression of nodule-related genes-GmENOD40,Gm NIN2b,and Gm EXPB2-was up-regulated.Furthermore,compared to monocropping,isoflavone secretion by soybean roots decreased,whereas flavonoid and flavonol secretion by both maize and soybean roots increased under intercropping.The abundance of differentially secreted flavonoid metabolites in the rhizosphere of both species declined when root contact was prevented by the barrier.In soybean roots,the expression of Gm CHS8 and Gm IFS1 was up-regulated,while Gm ICHG was down-regulated under root interaction.Most flavonoid and flavonol compounds showed positive correlations with nodule diameter.Nodule number,fresh weight,and the proportion of nodules larger than 0.2 cm increased in diverse soybean genotypes treated with maize root exudates,which contributed to enhanced nitrogen fixation capacity.Therefore,maize–soybean strip intercropping,combined with optimal row spacing,enhances the positive effects of underground root interactions and improves nodulation and nitrogen fixation in intercropped soybean.
基金supported by the Natural Science Foundation of Henan Province(242300421028)the National Natural Science Foundation of China(32372091)+3 种基金the Science and Technology Innovation Fund of Henan Agricultural University(202023CXZX002)to ZY.F.the National Key Research and Development Program of China(2021YFF1000304)to Q-W.S.the Natural Science Foundation Youth Fund project of Henan Province(232300421261)to Q-Q.Z.the China Postdoctoral Science Foundation(2024M750812),and Henan Postdoctoral Foundation.
文摘α.-Zeins,the major maize endosperm storage proteins,are transcriptionally regulated by Opaque2(O2)and prolamin-box-binding factor 1(PBF1),with Opaque11(O11)functioning upstream of them.However,whether O11 directly binds toα-zein genes and its regulatory interactions with O2 and PBF1 remain unclear.Using the small-kernel mutant sw1,which exhibits decreased 19-kDa and increased 22-kDaα-zein,we positionally clone O11 and find it directly binds to G-box/E-box motifs.O11 activates 19-kDaα-zein transcription,stronger than PBF1 but weaker than O2.Notably,PBF1 competitively binds to an overlapping E-box/P-box motif,and represses O11-mediated transactivation.Although O11 does not physically interact with O2,it participates in the O2-centered hierarchical network to enhanceα-zein expression.sw1 o2 and sw1 pbf1 double mutants exhibit smaller,more opaque kernels with further reduced 19-kDa and 22-kDaα-zeins compared to the single mutants,suggesting distinct regulatory effects of these transcription factors on 19-kDa and 22-kDaα-zein genes.Promoter motif analysis suggests that O11,PBF1,and O2 directly regulate 19-kDaα-zein genes,while O11 indirectly controls 22-kDaα-zein genes via O2 and PBF1 modulation.These findings identify the unique and coordinated roles of O11,O2,and PBF1 in regulatingα.-zein genes and kernel development.
基金Australian Research Council Linkage project(LP220100292)for partially supporting Mengzhu Wang’s PhD scholarship。
文摘There is increasing interest in developing reduced-crude protein(CP)diets for broiler chickens because their commercial adoption would generate a diverse range of advantages that would enhance the sustainability of the chickenmeat industry.However,the development of reduced-CP broiler diets is proving to be not straightforward,particularly when dietary CP reductions exceed 30 g/kg.The capacity of broilers to accommodate dietary CP reductions when offered maize-based diets is superior to their counterparts offered wheat-based diets.Numerous factors could be contributing to this difference but have yet to be identified with certainty.Maize-based,reduced-CP diets characteristically support better weight gains and efficiencies of feed conversion than wheat-based diets,but this better growth performance is associated with increased fat deposition,monitored as heavier relative abdominal fat-pad weights.This is an intriguing dichotomy.Insulin is a powerful anabolic hormone in mammalian species capable of promoting fat deposition,protein accretion and growth,but the importance of insulin in avian species is usually dismissed.This is because broiler chickens are considered both hyperglycaemic and resistant to insulin.However,the likelihood is that young broiler chickens are more sensitive to insulin than is generally recognised and the anabolic properties of insulin may be contributing to the diverse responses observed between maize and wheat in the context of reduced-CP diets.Dietary CP reductions may trigger increased plasma ammonia concentrations and metabolic acidosis,but both factors can influence insulin secretion and insulin resistance.Maize has slower rates of starch digestion and glucose absorption than wheat and it has been suggested that this generates a more sustained insulin release resulting in increased weight gains and fat deposition.If so,this could be driving the differences generated by the feed grain selected as the basis of reduced-CP diets.The intention of this review is to explore this proposition because if the causal factors of the differences between maize and wheat can be identified the development and acceptance of reduced-CP broiler diets should be accelerated.
基金financially supported by the National Natural Science Foundation of China (32071978)the National Key Research and Development Program of China (2022YFD2300901 and 2022YFD2300905)。
文摘High temperature stress (HT) significantly reduces maize yield by impairing starch accumulation in kernels.However,the mechanism by which HT affects starch synthesis remains controversial-whether through reduced assimilate supply or direct inhibition on kernel metabolism.To clarify these mechanisms,a heat-sensitive maize hybrid,Xianyu 335 (XY),was exposed to 30℃/20℃ (maximum/minimum temperature,control) and 40℃/30℃ for seven consecutive days during the seed setting stage.Synchronous pollination (SP),apical pollination (AP),and shading treatments were applied to manipulate the inherent source–sink ratio in maize plants.Results showed that apical kernel weight decreased by 11.9%under 40℃ in the SP treatment.The ^(13)C content,starch accumulation,and cell-wall invertase (CWIN) activity also declined by 15.9,36.7,and 16.4%,respectively,under HT.In the shading treatment,40℃/30℃ caused even greater reductions in^(13)C content,starch accumulation,and CWIN activity due to diminished assimilate supply.Conversely,in the AP treatment,starch content and CWIN activity increased by 22.0 and 18.5%,respectively,under 40℃/30℃,resulting in kernel weight and ^(13)C content similar to those in SP and shading treatments regardless of temperature.Consistent with apical kernels under AP,HT did not negatively affect middle kernels in either SP or shading treatments,as kernel weight and starch content remained unchanged under HT.Although all kernels were exposed to the same HT or control environment,their responses varied a lot.The impaired starch synthesis in apical kernels under HT was rescued by increasing carbon supply via AP treatment.The contrasting performance among middle kernels,apical kernels under AP,and apical kernels under SP or shading indicates that reduced carbon supply is a critical factor underlying inhibited starch accumulation.Our findings provide a theoretical basis for further understanding kernel abortion under HT.
基金supported by the National Natural Science Foundation of China(32071960)the National Key Research and Development Program of China(2018YFD0300603)。
文摘In maize production,the development of density-tolerant and lodging-resistant varieties has made dense planting an effective strategy for achieving high and stable yields,with superior hybrids serving as a prerequisite for successful highdensity cultivation.However,the photosynthetic mechanisms underlying improved density tolerance in maize hybrids released across different eras in China remain unclear.This study investigates 40 years of breeding progress toward enhanced photosynthetic traits under varying planting densities and elucidates the physiological and ecological bases of improved density tolerance in maize hybrids.A three-year field experiment was conducted from 2019 to 2021 to compare eight major Chinese hybrids from four decadal cohorts under three planting densities:45,000(D1),67,500(D2),and 90,000(D3)plants ha^(-1).At high density(D3),modern hybrids exhibited a more optimal canopy architecture and superior leaf photosynthetic performance compared to older hybrids,despite a slight reduction in specific leaf nitrogen.Notably,modern hybrids(2000s)were able to maintain higher net photosynthetic rates and photosynthetic nitrogen use efficiency(PNUE)at D3,resulting in the highest grain yield(GY),which was 118.47%greater than that of older hybrids(1970s).Leaf area duration after anthesis,total chlorophyll content,key photosynthetic enzyme activities,and maximum quantum efficiency of PSII photochemistry were all positively correlated with GY.Among these,PNUE showed the strongest correlation with grain yield and thus represents a key indicator for optimizing maize hybrids.Based on these findings,breeders should continue selecting hybrids under high-density and suboptimal conditions,focusing on optimizing population architecture and enhancing photosynthetic capacity while fine-tuning leaf nitrogen status to develop high-yielding,density-tolerant hybrids capable of sustaining long-term increases in maize grain yield.
基金supported by the National Natural Science Foundation of China(U2243235)the Shaanxi Provincial Department of Water Resources,China(2022slkj-6)。
文摘The irrigation districts of northern China face issues such as water scarcity,inability to effectively utilize flood resources,and groundwater overexploitation.In view of these challenges,this study proposes a new concept of deep storage irrigation through flood resources utilization.However,whether deep storage irrigation can recharge deep soil moisture and sustain crop production still requires further study.A two-year field experiment was conducted on summer maize in the Guanzhong Plain with five soil wetting layer depths(T1:60 cm;T2:90 cm;T3:120 cm;T4:150 cm;T5:180 cm)and soil saturation moisture content as the irrigation upper limit.The results presented that the ranges of deep soil moisture recharge in the100–200 cm soil profile(SMS_(100–200))was 73.34–267.42 and 0–150.03 mm in 2021(wet season)and 2022(normal season).When the effective precipitation and irrigation exceeded 390 mm,the SMS_(100–200)began to linearly increase.The highest grain yield(GY)were observed at T2 and T3 treatments in 2021(11.44 t ha^(-1))and 2022(11.25 t ha^(-1)),respectively.The maize GY of T4 in 2021 and T5 in 2022 were only 3.9 and 5.7%lower than the maximize GY,respectively.However,the SMS_(100–200)for T4 and T5 were 2.4 and 5.0 times that of T2 and T3 treatments in 2021 and 2022,respectively.Overall,the further increase in irrigation amounts induced only a slight decrease in grain yield,but it significantly increased deep soil moisture recharge.Therefore,the deep storage irrigation breaks through the traditional idea of water-saving irrigation with limited water resources,which can be utilized as an effective alternative to address the issues of water scarcity,low flood resources utilization,and groundwater level declines in the irrigation districts of northern China.
基金supported by grants from the National Natural Science Foundation of China(31771876)the Biological Breeding Program of State Key Laboratory of Sichuan Agricultural University,China(SKL-ZY202234)the Sichuan Province Science and Technology Program,China(2021YFYZ0011 and 2021YFYZ0017)。
文摘Carbohydrate partitioning from source to sink tissues is essential for plant growth and development.However,in maize(Zea mays L.),the molecular mechanisms by which callose synthase genes regulate this process remain largely unexplored.This study demonstrates that mutation of maize callose synthase12(Zm Cals12)results in increased carbohydrate accumulation in photosynthetic leaves but decreased carbohydrate content in sink tissues,leading to plant dwarfing and male sterility.Histochemical β-glucuronidase(GUS)activity assay and m RNA in situ hybridization(ISH)revealed that Zm Cals12 expression mainly occurs in the vascular transport system.Zm Cals12 loss-of-function decreased callose synthase activity and callose deposition in plasmodesmatas(PDs)and surrounding phloem cells(PCs)of the vascular bundle.The drop-and-see(DANS)assay indicated reduced PD permeability in photosynthetic cells and diminished transport competence of leaf veins in Zmcals12 mutants,resulting in decreased symplastic transport.Paraffin section analysis revealed that less-developed vascular cells(VCs)in Zmcals12 mutants likely disrupted sugar transport,contributing to the pleiotropic phenotype.Furthermore,impaired sugar transport inhibited internode development by suppressing auxin(IAA)biosynthesis and signaling in Zmcals12 mutant.These findings elucidate the mechanism by which Zm Cals12-mediated callose deposition and symplastic transport regulate maize growth and development.
基金supported by the Fundamental Research Funds for the Central Universities(N2001020)the National Natural Science Foundation of China(41201359).
文摘Sand dust belts span approximately one-fifth of the global land surface.In these regions,dust tends to settle on vegetation surfaces,altering the observed reflectance and affecting remote sensing detections.To enhance the accuracy of maize growth monitoring in dust-affected regions,this study aims to quantify the effect of sand dust retention on maize during the tasseling stage in the Kashgar Prefecture,Xinjiang Uygur Autonomous Region,China,by analyzing changes in canopy reflectance and vegetation indices.First,field sampling was conducted to measure the key canopy structure parameters and dust retention levels of maize,and laboratory spectral measurements were performed on leaf spectral properties under gradient dust retention.The measured data were then used to drive the LargE-Scale remote sensing data and image Simulation framework(LESS)model for simulating realistic maize canopy spectra across different dust levels,with validation against Sentinel-2 imagery.Second,on the basis of the simulated and satellite-derived spectra,the dust resistance of 36 common vegetation indices was systematically evaluated,and new robust dust-resistant indices were developed.The results showed that compared with dust-free maize,the canopy reflectance of dust-retained maize followed an increase–decrease–increase pattern,with critical turning points at 735 and 1325 nm.The maximum reflectance difference of–0.11755(change rate:29.002%)occurred within the 735–1325 nm range at 24 g/m^(2)dust retention,and the minimum reflectance difference of 0.04285(change rate:148.950%)was observed in the 350–735 nm range under the same dust retention level.Among the 36 vegetation indices,only the global environment monitoring index(GEMI)and the ratio of transformed chlorophyll absorption in reflectance index to optimized soil-adjusted vegetation index(TCARI/OSAVI)exhibited dust resistance,with GEMI being effective below 6 g/m^(2)and TCARI/OSAVI remaining stable across all levels(average ratio:0.970).The newly developed indices in this study,(RE3–RE2)/(NIR–RE2),(RE3–RE2)/(RE4–RE2),and(NIR–RE2)/(RE4–RE2),retained values within the predefined dust-resistant range over the full dust retention levels of 0–24 g/m^(2),thus showing a more stable dust resistance compared with the commonly used 36 vegetation indices.Specially,(RE3–RE2)/(RE4–RE2)performed the most robustly in Sentinel-2 imagery,that is,58.020%of pixels were within the dust-resistant range,and an average ratio of 0.937 was obtained for the original-spectra index.This study provides a scientific basis for crop monitoring and management in dust-affected regions.
基金the financial support of the Genetically Modified Organisms Breeding Major Project, China (2011ZX08003-001)the National Basic Research Program of China (973 Program, 2009CB118902)the National Natural Science Foundation of China (30970231)
文摘A novel insecticidal gene crylAh was cloned from Bacillus thuringiensis isolate BT8 previously for plant genetic engineering improvement. Truncated active CrylAh toxin has a toxicity level similar to that of the full-length CrylAh toxin. In this study, plant expression vector pMhGM harboring truncated crylAh gene was transformed into maize （Zea mays L.） immature embryos by Agrobacterium tumefaciens-mediated transformation at which maize alcohol dehydrogenase matrix attachment regions （madMARs） were incorporated on both sides of the gene expression cassette to improve gene expression. A total of 23 PCR positive events were obtained with a transformation efficiency of 5% around. Bioassay results showed that events 1-4 and 1-5 exhibited enhanced resistance to the Asian corn borer （Ostriniafurnacalis）. These two events were further confirmed by molecular analysis. Southern blot suggested that a single copy of the crylAh gene was successfully integrated into the maize genome. Western blot and ELISA showed that the foreign gene crylAh was expressed stably at high level in maize and could be inherited stably over generations. The results of a bioassay of T l-T4 transgenic maize plants indicated that the transgenic plants were highly toxic to the Asian corn borer and their resistance could be inherited stably from generation to generation. Thus, events 1-4 and 1-5 are good candidates for the breeding of insect-resistant maize.
基金Supported by Strategic Leading Science and Technology Project of Chinese Academy of Sciences(XDA28130504)Special Project of Agricultural Science and Technology Innovation Leaping Project of Heilongjiang Academy of Agricultural Sciences(HNK2019CX14)Scientific Research Fund Project of Heilongjiang Provincial Scientific Research Institutes(CZKYF2021C008)。
文摘In order to promote the research of transgenic insect-resistant maize,the target gene were transferred into maize material Hi-Ⅱ by Agrobacterium-mediated genetic transformation of maize embryos,and maize plants with CryNGc insect-resistant genes were cultured by explant infection,co-culture and differentiation screening to study the genetic expression and resistance of exogenous genes in the offspring.The results showed that the infection effect was the best when the size of young maize embryo was 1.2-1.8 mm.Ten positive transformed plants with CryNGc insect-resistant genes were successfully obtained,and the transformation efficiency was 1.428‰.
基金This is the publication No.36 produced within the framework of the project"Assessing and Monitoring the Impacts of Genetically Modified Plants on Agroecosystems(AMIGA)",funded by the European Commission in the Framework Programme 7.THEME[KBBE.2011.3.5-01].
文摘The use of genetically modified varieties tolerant to herbicides(HT varieties)and resistant to insects(Bt varieties)in combination with application of a broad-spectrum herbicide such as glyphosate could be an effective option for the simultaneous control of weeds and pests in maize.Nevertheless,the possible impact of these tools on nontarget arthropods still needs to be evaluated.In a field study in central Spain,potential changes in populations of canopy-dwelling arthropods in Bt maize under different weed management options,including glyphosate application,were investigated.Canopy-dwelling arthropods were sampled by visual inspection and yellow sticky traps.The Bt variety had no effect on any group of studied arthropods,except for the expected case of corn borers—the target pests of Bt maize.Regarding the effects of herbicide regimes,the only observed difference was a lower abundance of Cicadellidae and Mymaridae on yellow sticky traps in plots not treated with pre-emergence herbicides.This effect was especially pronounced in a treatment involving two glyphosate applications.The decrease in Cicadellidae and Mymaridae populations was associated with a higher density of weeds in plots,which may have hindered colonization of the crop by leafhoppers.These differences,however,were only significant in the last year of the study.The low likelihood of the use of glyphosate-and herbicide-tolerant varieties for weed control triggering important effects on the nontarget arthropod fauna of the maize canopy is discussed.
基金supported by the National Key Research and Development Program of China(2022YFD190160304 and 2018YFD0301206)Natural Science Foundation of Sichuan Province(2022NSFSC0013)Sichuan Provincial Maize Innovation Team Construction Project(SCCXTD-2023-02).
文摘A four-year field experiment was conducted with two cultivars and four N rate to investigate the spatiotemporal characteristics of leaf senescence in maize after silking and its response to N fertilizer rates on them,as well as to reveal the differences in post-silking chlorophyll degradation between low-N-tolerant cultivars.The results showed that the order of leaf senescence after silking in maize was lower leaf>upper leaf>ear leaf,leaf tip>middle>base.Increasing N fertilizer down-regulated the expression of ZmCLH2 and ZmPPH in the leaves at 10-30 d after silking,reducing CLH and PPH activities,thereby delaying the leaf senescence.These effects were more prominent in low-N-sensitive cultivar Xianyu 508(XY508)than in low-N-tolerant cultivar Zhenghong 311(ZH311),especially in the lower leaves and leaf tip.Under low N condition,leaf yellowing and chlorophyll degradation occurred later and slower in ZH311 than in XY508.This resulted in a higher post-silking dry matter accumulation and grain yield in ZH311,which may be one of the important physiological bases of low nitrogen tolerant cultivars.Future research should focus on developing low-N-tolerant maize cultivars with slower leaf senescence near the ear after silking.
基金supported by the National Key Research and Development Program of China(2021YFD1200703 and 2022YFF1001602)the National Science Foundation of China(32272024 and 32171940)+2 种基金the Pinduoduo-China Agricultural University Research Fund(PC2023B01001)the Chinese Universities Scientific Fund(2022TC142)the 2115 Talent Development Program of China Agricultural University。
文摘Maize(Zea mays),which is a vital source of food,feed,and energy feedstock globally,has significant potential for higher yields.However,environmental stress conditions,including drought and salt stress,severely restrict maize plant growth and development,leading to great yield losses.Leucine-rich repeat receptor-like kinases(LRR-RLKs)function in biotic and abiotic stress responses in the model plant Arabidopsis(Arabidopsis thaliana),but their roles in abiotic stress responses in maize are not entirely understood.In this study,we determine that the LRR-RLK ZmMIK2,a homolog of the Arabidopsis LRR-RK MALE DISCOVERER 1(MDIS1)-INTERACTING RECEPTOR LIKE KINASE 2(MIK2),functions in resistance to both drought and salt stress in maize.Zmmik2 plants exhibit enhanced resistance to both stresses,whereas overexpressing ZmMIK2 confers the opposite phenotypes.Furthermore,we identify C2-DOMAIN-CONTAINING PROTEIN 1(ZmC2DP1),which interacts with the intracellular region of ZmMIK2.Notably,that region of ZmMIK2 mediates the phosphorylation of ZmC2DP1,likely by increasing its stability.Both ZmMIK2 and ZmC2DP1 are mainly expressed in roots.As with ZmMIK2,knockout of ZmC2DP1 enhances resistance to both drought and salt stress.We conclude that ZmMIK2-ZmC2DP1 acts as a negative regulatory module in maize drought-and salt-stress responses.
基金supported by the State Key Laboratory of Arid Land Crop Science, Gansu Agricultural University,China (GSCS-2022-Z02)the National Key R&D Program of China (2022YFD1900300)+2 种基金the National Natural Science Foundation of China (32260549)the Innovation Group of Basic Research in Gansu Province, China (25JRRA807)the Major Special Research Projects in Gansu Province, China (22ZD6NA009)。
文摘The application of organic fertilizers has become an increasingly popular practice in maize production to reduce thegaseous nitrogen(N) loss and soil degradation caused by inorganic fertilizers. Organic fertilizer plays a key rolein improving soil quality and stabilizing maize yields, but few studies have compared different substitution rates. Afield study was carried out in 2021 and 2022, based on a long-term trial initiated in 2016, which included five organicfertilizer N substitution rates with equal inputs of 200 kg N ha^(–1): 0% organic fertilizer(T1, 100% inorganic fertilizer),50.0% organic+50.0% inorganic fertilizer(T2), 37.5% organic+62.5% inorganic fertilizer(T3), 25.0% organic+75.0%inorganic fertilizer(T4), and 12.5% organic+87.5% inorganic fertilizer(T5), as well as a no fertilizer control(T6). Theresults of the two years showed that T3 and T1 had the highest grain yield and biomass, respectively, and there wasno significant difference between T1 and T3. Compared with T1, the 12.5, 25.0, 37.5, and 50.0% substitution rates in T5, T4, T3, and T2 significantly reduced total nitrogen losses(NH_(3), N_(2)O) by 8.3, 16.1, 18.7, and 27.0%, respectively.Nitrogen use efficiency(NUE) was higher in T5, T3, and T1, and there were no significant differences among them.Organic fertilizer substitution directly reduced NH_(3)volatilization and N_(2)O emission from farmland by lowering theammonium nitrogen and alkali-dissolved N contents and by increasing soil moisture. These substitution treatmentsreduced N_(2)O emissions indirectly by regulating the abundances of AOB and nirK-harboring genes by promotingsoil moisture. Specifically, the 37.5% organic fertilizer substitution reduces NH_(3)volatilization and N_(2)O emission from farmland by reducing the ammonium nitrogen and alkali-dissolved N contents and increasing moisture, which negatively regulate the abundance of AOB and nir K-harboring genes to reduce N_(2)O emissions indirectly in rainfed maize fields on the Loess Plateau of China.
