Arogenate dehydratase(ADT)catalyzes the final step in phenylalanine synthesis and is crucial for plant development and metabolism.Previously,we demonstrated that the ADT/prephenate dehydratase ZmADT2 is essential for ...Arogenate dehydratase(ADT)catalyzes the final step in phenylalanine synthesis and is crucial for plant development and metabolism.Previously,we demonstrated that the ADT/prephenate dehydratase ZmADT2 is essential for maize resistance to Ustilago maydis and for overall plant development.In this study,we explored the role of ZmADT2 in maize kernel development.The mmsu mutant,a dysfunctional ZmADT2 variant,exhibits delayed embryo and endosperm development,along with deficiencies in carbohydrate and protein storage.Transcriptome analysis revealed differential expression of many kernel compartment-specific genes between mmsu and wild-type(WT)kernels,with impaired nutrient accumulation and auxin signaling pathway in the mmsu endosperm.Compared to WT,ZmADT2 mutation led to reduced auxin levels and smaller endosperm cell size.Exogenous auxin rescued the small kernel phenotype of mmsu.Additionally,auxin distribution was reduced in the basal endosperm transfer layer(BETL),causing defects in its development and function,including reduced transfer cell elongation,cell wall ingrowth and nutrient uptake.These findings suggest that ZmADT2 mediated mediates an auxin signaling pathway that is essential for maize kernel development.展开更多
Pentatricopeptide repeat(PPR)proteins are a large group of eukaryote-specific RNA-binding proteins that play pivotal roles in plant organelle gene expression.Here,we report the function of PPR21 in mitochondrial intro...Pentatricopeptide repeat(PPR)proteins are a large group of eukaryote-specific RNA-binding proteins that play pivotal roles in plant organelle gene expression.Here,we report the function of PPR21 in mitochondrial intron splicing and its role in maize kernel development.PPR21 is a typical P-type PPR protein targeted to mitochondria.The ppr21 mutants are arrested in embryogenesis and endosperm development,leading to embryo lethality.Null mutations of PPR21 reduce the splicing efficiency of nad2 intron 1,2,and 4 and impair the assembly and activity of mitochondrial complex I.Previous studies show that the P-type PPR protein EMP12 is required for the splicing of identical introns.However,our protein interaction analyses reveal that PPR21 does not interact with EMP12.Instead,both PPR21 and EMP12 interact with the small MutS-related(SMR)domain-containing PPR protein 1(PPR-SMR1)and the short P-type PPR protein 2(SPR2).PPR-SMR1 interacts with SPR2,and both proteins are required for the splicing of many introns in mitochondria,including nad2 intron 1,2,and 4.These results suggest that a PPR21-(PPR-SMR1/SPR2)-EMP12 complex is involved in the splicing of nad2 introns in maize mitochondria.展开更多
Strip-till(ST),including straw mulching in the inter-row and localized fertilization in the intra-row,is a conservation tillage system for improving soil quality and crop growth.However,the yield advantage of maize un...Strip-till(ST),including straw mulching in the inter-row and localized fertilization in the intra-row,is a conservation tillage system for improving soil quality and crop growth.However,the yield advantage of maize under ST compared to conventional tillage(CT)remains unstable,and the strategies to increase maize yield under ST are unclear.This study aims to understand the physiological mechanism underlining maize yield formation under ST by comparing two maize cultivars,DKM753 and DK517,with contrasting yield performance in ST versus CT systems.Compared to CT,ST resulted in a 4.5%yield increase for DKM753 but a 5.6%decrease for DK517.These yield differences were primarily attributed to variations in grain number per ear(GN).During the rapid growth stage(V14-R3),i.e.,two weeks before and after silking,DKM753 showed a 6.7%increase in maximum growth rate(V_(max))and a 6.3%increase in average growth rate(V)under ST,whereas DK517 exhibited decline of 8.5%in V_(max) and 12.3%in V.Significant positive correlations are observed between V_(max) and V with GN under ST(R^(2)=0.79 and R^(2)=0.90,respectively).Enhanced dry matter accumulation in DKM753 under ST was attributed to increased leaf expansion rates,contributing to a larger photosynthate source.The straw mulching and localized nitrogen fertilization increased root-zone nitrogen availability at silking in ST compared to CT.DKM753 had a greater root system which made better use of the soil N and lead to an increased leaf nitrogen accumulation by 14.9%under ST.It is concluded that maize yield under the strip-till system is determined by grain number per ear,which can be increased by increasing nitrogen accumulation,plant growth,and ear development around silking stage.A sound root system can efficiently utilize soil nitrogen resources under the strip-till system,increasing plant nitrogen accumulation and thereby promoting plant growth.展开更多
Carotenoids are the largest group of natural pigments responsible for the yellow,orange,and red colors in plant kernels,fruits,and leaves(Gupta and Hirschberg,2021).In plants,carotenoids are involved in manybiological...Carotenoids are the largest group of natural pigments responsible for the yellow,orange,and red colors in plant kernels,fruits,and leaves(Gupta and Hirschberg,2021).In plants,carotenoids are involved in manybiological processes,such as acting as accessory light-harvesting pigments in photosynthesis,participating in photoprotection,and serving as precursors for the hormones abscisic acid(ABA)and strigolactones(Ruiz-Sola and Rodriguez-Concepcion,2012).展开更多
Phosphorylation is one of the major posttranslational modifications to control plant growth and development.Opaque2(O2)represents a central hub for endosperm filling,which largely determines seed yield and nutrient st...Phosphorylation is one of the major posttranslational modifications to control plant growth and development.Opaque2(O2)represents a central hub for endosperm filling,which largely determines seed yield and nutrient storage in maize.However,it still remains unclear how O2 phosphorylation orchestrates endosperm filling and nutrient quality.Here,we systematically identified the phosphorylation sites of O2 during endosperm filling.A total of 18 phosphorylation sites were found in O2 and five sites were identified to apparently modulate its subcellular localization and transactivation capacity.In addition,a conserved protein kinase CK1 was confirmed to interact with and phosphorylate O2 at the residue Threonine(T)202 to promote O2-mediated transactivation and protein stability.Overexpression of CK1 resulted in increased kernel size,100-kernel weight and nutrient storage.Phosphorylation-mimic O2 seeds at T202 exhibited enhanced kernel dimension,test weight,vitreous endosperm area and nutrient accumulation,whereas the phosphorylation-deficient O2 seeds did not.Collectively,this study establishes a comprehensive phosphocode atlas of O2 during endosperm filling and highlights the importance of phosphorylation modification in O2 to precisely orchestrate maize yield and nutrient quality.展开更多
Maize(Zea mays L.)is one of the world's most important staple crops,and is used for manufacturing food,feed,and industrial products.A key factor in maize yield is the grain weight,which directly influences product...Maize(Zea mays L.)is one of the world's most important staple crops,and is used for manufacturing food,feed,and industrial products.A key factor in maize yield is the grain weight,which directly influences productivity.In this study,we revealed the role of smk23 in maize kernel development.The ethyl methanesulfonate mutant smk23 is characterized by substantially reduced kernel weight.Through map-based cloning,smk23 was found to be located on Chr5 and encode a putative B-type response regulator,Zm RR5.A change from G to A occurs in the coding sequence of Zm RR5,resulting in the early termination of smk23.In Arabidopsis,B-type response regulators are involved in cytokinin signaling.Histological analysis and in situ hybridization of the mutant revealed abnormal endosperm development,particularly in the basal endosperm transfer layer(BETL),a specialized tissue critical for nutrient transport from the maternal tissues to the developing kernel.Zm RR5 positively regulates key genes involved in BETL development and function,including MRP1 and TCRR1.Furthermore,RNA sequencing revealed that several genes closely linked to BETL development,including BETL2,MEG1,and MN1,were significantly downregulated in smk23.These genes are essential for nutrient transport,tissue development and signal transduction.In addition,haploid analysis of Zm RR5 revealed natural variations(Hap 2)that may contribute to the increased kernel yield.Disruption of Zm RR5 function in smk23 leads to defects in BETL development,impairing its ability to transport nutrients,and ultimately resulting in a smaller kernel size.This study provides new insights into the molecular mechanisms through which Zm RR5 regulates maize kernel development and offers potential strategies for improving grain yield.展开更多
Inferior grains exhibit delayed developmental processes and reduced metabolic activities compared to superior grains,leading to unstable rice yield and quality.While significant advancements have been achieved in eluc...Inferior grains exhibit delayed developmental processes and reduced metabolic activities compared to superior grains,leading to unstable rice yield and quality.While significant advancements have been achieved in elucidating the physiology of endosperm filling in inferior grains,the role of the embryo remains underexplored and warrants comprehensive investigation.Two Wuyujing 3 mutants,DW024(relatively synchronous;syn-DW024)and DW179(significantly asynchronous;asyn-DW179),with different grain-filling patterns were used in this study.Samples of superior and inferior grains were collected at intervals from 5 to 60 d after fertilization and subsequently dissected into subsamples of the embryo and endosperm.Histochemical staining,biochemical analysis,and RNA sequencing(RNA-seq)were combined to systematically compare developmental and physiological traits between superior and inferior grains.Combining hierarchical clustering of mRNA datasets revealed three developmental phases of the endosperm and embryo:morphogenesis,endosperm filling/embryo enlargement,and maturation.In both syn-DW024 and asyn-DW179,the duration of the endosperm/embryo morphogenesis phase was identical in superior and inferior grains.The inferior grains of asyn-DW179 exhibited a 10-day prolongation in the endosperm filling phase and a 20-day extension in the embryo enlargement phase compared to the superior grains.The endosperm of inferior grains exhibited higher contents of sugars and free amino acids,along with slower accumulation of storage compounds,which was associated with the down-regulation of genes for starch synthesis and ABA signaling.In addition,transporters for nutrient exchanges between endosperm and embryo were down-regulated,suggesting a potential role of the embryo in adjusting the endosperm filling process.Collectively,our results reveal that the prolonged phases of endosperm filling and embryo enlargement may underlie the impaired development of inferior grains,offering a new perspective for breeding or cultivating rice with uniform grain quality.展开更多
DCPTA （2-diethylaminoethyl-3, 4-dichlorophenylether） is a new plant regulator which can be used to regulate growth and development for crops. Experiments on maize seedlings were conducted in the growth chamber to st...DCPTA （2-diethylaminoethyl-3, 4-dichlorophenylether） is a new plant regulator which can be used to regulate growth and development for crops. Experiments on maize seedlings were conducted in the growth chamber to study the effects of foliar applied DCPTA. The plant pots were placed in a completely randomized design with three replicates. The maize seedlings were treated with 0 mg·L-1 （control）, 20 mg·L-1 and 40 mg·L-1 DCPTA solution. The effects of DCPTA on the photosynthetic characteristics （photosynthesis, stomata conductance, intercellular CO2, and transpiration rate）, related physiological characteristics （contents of soluble sugar and starch）, chlorophyll fluorescence parameters （Fo, Fro, Fv/Fm, Fv/Fo, qP, and qN） and the weight of dry matter in maize seedling were studied. The results showed that DCPTA enhanced photosynthesis of maize seedling. In general, photosynthetic rate in leaves was significantly promoted through spraying DCPTA solution, and 40 rag＂ L~ DCPTA was found to be the best concentration for maize. The relationship between stomata conductance and transpiration rate in maize leaves could be described as linear. With regard to the chlorophyll fluorescence parameters, our fmdings showed that 40 mg·L-1 DCPTA in maize seedling caused an increase in Fm, Fv/Fm, Fm/Fo, qP and a decrease in Fo and qN at some time points checked. It is suggested that DCPTA increased photosynthetic rate by raising both the content of chlorophyll and activities of PSII and the contents of sugar and starch. Compared with the control, the treated maize seedling caused an increase in plant height, root length, shoot dry mass, root dry mass, or the total （root plus shoot） dry mass.展开更多
Morphological variations of the nucleus in starchy endosperm cell were observed by theelectron-transmisson microscope during endosperm development in rice. Along with thedevelopment of the starchy endosperm, the nucle...Morphological variations of the nucleus in starchy endosperm cell were observed by theelectron-transmisson microscope during endosperm development in rice. Along with thedevelopment of the starchy endosperm, the nuclei of the cells showed chromatin condensation,the typical feature of programmed cell death (PCD). The nuclei also showed nucleusdeformation, disruption of nuclear envelope, nucleoplasm leaking into the cytoplasm andnucleus disintegration resulting in nuclear residue formation. From the nucleus deformationto the nucleus disintegration, the morphological changes of the nucleus were orderlyprogressive. This indicated that the cell death of starchy endosperm in rice wasprogrammed cell death. Evans Blue staining observation showed that the cell death wasinitially detected in the central part of starchy endosperm in rice, then expandedoutward. The activities of superoxide dismutase (SOD) and catalase (CAT) in rice starchyendosperm both descended continuously as development progressed. The analysis of DNA ofrice starchy endosperm did not show the presence of DNA laddering. The above resultsshowed that the cell death of starchy endosperm in rice was a special form of PCD.展开更多
Chromatin accessibility plays a vital role in gene transcriptional regulation.However,the regulatory mechanism of chromatin accessibility,as well as its role in regulating crucial gene expression and kernel developmen...Chromatin accessibility plays a vital role in gene transcriptional regulation.However,the regulatory mechanism of chromatin accessibility,as well as its role in regulating crucial gene expression and kernel development in maize(Zea mays)are poorly understood.In this study,we isolated a maize kernel mutant designated as defective kernel219(dek219),which displays opaque endosperm and embryo abortion.Dek219 encodes the DICER-LIKE1(DCL1)protein,an essential enzyme in mi RNA biogenesis.Loss of function of Dek219 results in significant reductions in the expression levels of most mi RNAs and histone genes.Further research showed that the Heat shock transcription factor17(Hsf17)-Zm00001d016571 module may be one of the factors affecting the expression of histone genes.Assay results for transposase-accessible chromatin sequencing(ATAC-seq)indicated that the chromatin accessibility of dek219 is altered compared with that of wild type(WT),which may regulate the expression of crucial genes in kernel development.By analyzing differentially expressed genes(DEGs)and differentially accessible chromatin regions(ACRs)between WT and dek219,we identified 119 candidate genes that are regulated by chromatin accessibility,including some reported to be crucial genes for kernel development.Taken together,these results suggest that Dek219 affects chromatin accessibility and the expression of crucial genes that are required for maize kernel development.展开更多
Drought is a main abiotic stress factor hindering plant growth,development,and crop productivity.Therefore,it is crucial to understand the mechanisms by which plants cope with drought stress.Here,the function of the m...Drought is a main abiotic stress factor hindering plant growth,development,and crop productivity.Therefore,it is crucial to understand the mechanisms by which plants cope with drought stress.Here,the function of the maize peroxidase gene ZmPRX1 in drought stress tolerance was investigated by measurement of its expression in response to drought treatment both in a ZmPRX1 overexpression line and a mutant line.The higher root lignin accumulation and seedling survival rate of the overexpression line than that of the wild type or mutant support a role for ZmPRX1 in maize drought tolerance by regulating root development and lignification.Additionally,yeast one-hybrid,Dule luciferase and ChIP-qPCR assays showed that ZmPRX1 is negatively regulated by a nuclear-localized ZmWRKY86 transcription factor.The gene could potentially be used for breeding of drought-tolerant cultivars.展开更多
With the development of China＇s market economy, the international grain supply situation is increasingly tense, and the grain has been regarded as an important international strategic resource in the international ma...With the development of China＇s market economy, the international grain supply situation is increasingly tense, and the grain has been regarded as an important international strategic resource in the international market. Due to the reduction of international grain output and expected inflation, the gap between maize supply shortage and increasing demand is apparent in China, so that China is described as a worrying importer country. By using SWOT analysis belonging to the field of enterprise strategic management, this paper analyzed the current maize industry development in Heilongjiang Province as an entry point, the strength, weakness and opportunity and threat were put forward. Thereby, the developing principles and strategies were proposed to stimulate the maize industry development in Heilongjiang Province, which would lay a good foundation of 50 billion kilograms grain production capacity by 2015 in China, as well as the economic development and local farmers＇ income increase.展开更多
Although several pentatricopeptide repeat(PPR) proteins are involved in post-transcriptional processing of mitochondrial RNA, it is unclear which specific protein is involved in the RNA editing of ccmC in maize(Zea ma...Although several pentatricopeptide repeat(PPR) proteins are involved in post-transcriptional processing of mitochondrial RNA, it is unclear which specific protein is involved in the RNA editing of ccmC in maize(Zea mays). Here we report the identification of the maize empty pericarp 601(emp601) mutant and the map-based cloning of the Emp601 gene, which encodes an E2-type PPR protein that is targeted to mitochondria. A single-nucleotide deletion in the emp601 mutant caused a frameshift and introduced a premature stop codon into the predicted EMP601. This mutation was associated with reduced accumulation of mitochondrial complex Ⅲ as well as with inhibition of growth and differentiation of basal endosperm transfer layer cells, leading to final degeneration of the embryo and endosperm. We determine that loss of EMP601 function prevents the C-to-U RNA editing of the mitochondrial transcript ccmC at position 358.EMP601 binds to the ccmC transcript and directly interacts with Multiple organellar RNA editing factor 8and may be a component of the plant mitochondrial editosome. We conclude that EMP601 functions in RNA editing of mitochondrial ccmC transcripts and influences mitochondrial function and seed development.展开更多
[ Objective] To investigate the effects of planting date on development and yield of forage maize and to determine the appropriate plant- ing date for forage maize. [ Method] Using forage maize 50 as experimental mate...[ Objective] To investigate the effects of planting date on development and yield of forage maize and to determine the appropriate plant- ing date for forage maize. [ Method] Using forage maize 50 as experimental material, the development of forage maize was observed, and the yield of forage in the later grain filling period and mature stage was measured, after the maize were planted at different dates, r Remltl With the delaying planting date, phenological period was delayed, and the duration of the same growing stage was shortened among different treatments. The shor- test duration days of anthesis maturity period appeared in the treatment of planting in June 15, and the duration days of anthesis maturity period was increased in the treatment of planting in June 30. With the delaying planting date, the height of maize plant in the five leaf stage was increased. The highest plant in the jointing stage appeared in the treatment of planting in June 15. However, the highest plant appeared in the treatment of planting in May 30 after the jointing stage. The number of green leaves per plant was reduced with the delaying planting date in the tasseling stage, and it was increased with the delaying planting date from later grain filling period to mature stage. With the delaying planting date, the fresh matter yield, forage yield and grain yield were reduced. [ Conclusion] The study provides theoretical and practical reference for high-yield cultivation of forage maize.展开更多
The occurrence, distribution, and rapid molecular detection technology of Heterodera zeae Koshy et al. 1971, have been reported in China. We explored the biological characteristics of H. zeae sampled in Henan Province...The occurrence, distribution, and rapid molecular detection technology of Heterodera zeae Koshy et al. 1971, have been reported in China. We explored the biological characteristics of H. zeae sampled in Henan Province, China to understand its interaction with plants. Cysts and second-stage juveniles(J2s) were identified under an optical and scanning electron microscope, internal transcribed spacer(ITS) phylogenetic tree, and sequence characterized amplified region(SCAR)-PCR analyses. The optimum hatching temperatures of H. zeae were 30°C and 28°C, with cumulative hatching rates of 16.5 and 16.1%, respectively, at 30 days post-hatching(dph). The hatching rate of H. zeae eggs was improved by 20-and 50-time maize soil leachate and root juice, and 10-time root exudates. The hatching rate in 10-time root exudates was the highest(25.9%). The 10-time root exudates of maize and millet produced the highest hatching rate at 30 dph(25.9 and 22.9%, respectively), followed by wheat(19.9%), barley(18.3%), and rice(17.6%). Heterodera zeae developed faster in maize than in other crops. Fourth-stage juveniles(J4s) were detected in maize roots 8 days post-inoculation(dpi) at 28°C but not in other crops. Combined with hatching tests, the Huang–Huai–Hai summer maize region and the south and central-southwest mountainous maize areas are highly suitable for H. zeae in China. This is the first systematically study of the hatching and infection characteristics on different plant hosts of corn cyst nematode H. zeae in temperate regions. This study laid a theoretical foundation for the rapid spread and high environmental adaptability of corn cyst nematode.展开更多
Maize research at Institute for Agricultural Research, Samaru, Nigeria resulted in sustained growth in yields in the last two decades. Maize is grown throughout the country with guinea savanna as the most important ma...Maize research at Institute for Agricultural Research, Samaru, Nigeria resulted in sustained growth in yields in the last two decades. Maize is grown throughout the country with guinea savanna as the most important maize growing zone. In the last five years, four new open pollinating varieties developed in collaboration with the International Institute of Tropical Agriculture （IITA, Ibadan） had been released for production. Hybrid varieties are also marketed by seed companies. The research was focused on variety improvement, improved management practices, integrated pests and disease control, soil fertility management, on-farm testing of improved production packages and socio-economics of production as well as adoption studies. The recently released quality protein maize has improved the nutritional status of vulnerable groups. Drought tolerant maize for Africa research project has contributed to sustainable maize production, poverty reduction and food security in the continent.展开更多
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
Endosperm mutants are critical to the studies on both starch synthesis and metabolism and genetic improvement of starch quality in maize.In the present study,a novel maize endosperm mutant A0178 of natural variation w...Endosperm mutants are critical to the studies on both starch synthesis and metabolism and genetic improvement of starch quality in maize.In the present study,a novel maize endosperm mutant A0178 of natural variation was used as the experimental material and identified and then characterized.Through phenotypic identification,genetic analysis,main ingredients measurement and embryo rescue,development of genetic mapping population from A0178,the endosperm mutant gene was located.The results showed that the mutant exhibited extremely low germination ability as attributed to the inhibited embryo development,and amounts of sugars were accumulated in the mutant seeds and more sugars content was detected at 23 days after pollination(DAP)in A0178 than B73.Employing genetic linkage analysis,the mutant trait was mapped in the bin 5.04 on chromosome 5.Sequence analysis showed that two sites of base transversion and insertion presented in the protein coding region and non-coding region of the mutant brittle-1(bt1),the adenylate translocator encoding gene involved in the starch synthesis.The single base insertion in the coding region cause frameshift mutation,early termination and lose of function of Brittle-1(BT1).All results suggested that bt1 is a novel allelic gene and the causal gene of this endosperm mutant,providing insights on the mechanism of endosperm formation in maize.展开更多
Ultracytochemical localization of ATPase during development of rice endosperm was performed using a lead phosphate precipitation technique. The results indicated that, at the coenocyte and cellularization stages, acti...Ultracytochemical localization of ATPase during development of rice endosperm was performed using a lead phosphate precipitation technique. The results indicated that, at the coenocyte and cellularization stages, active ATPase was mainly distributed in an embryo sac wall, nucleus, and plasma membrane. At the early stage of development and differentiation, active ATPase was observed in the plasma membrane. At the grain filling stage, ATPase was highly active in the plasma membrane, intercellular space, and plasmodesmata in aleurone, moderately active on the plasma membrane in subaleurone. In starchy endosperm, ATPase was localized in the plasma membrane and degenerated nucleus. ATPase activity also appeared around vacuole and protein body in endosperm cell. The relationships between the ultracytochemical localization of ATPase and its function during the development of rice endosperm were discussed. Overall, ATPase was involved in the process of nutrition absorption and protein synthesis.展开更多
基金funded by the National Natural Science Foundation of China(32071921)Key R&D Program of Shandong Province,China(2021LZGC022)Taishan Scholars Project(ts201712024).
文摘Arogenate dehydratase(ADT)catalyzes the final step in phenylalanine synthesis and is crucial for plant development and metabolism.Previously,we demonstrated that the ADT/prephenate dehydratase ZmADT2 is essential for maize resistance to Ustilago maydis and for overall plant development.In this study,we explored the role of ZmADT2 in maize kernel development.The mmsu mutant,a dysfunctional ZmADT2 variant,exhibits delayed embryo and endosperm development,along with deficiencies in carbohydrate and protein storage.Transcriptome analysis revealed differential expression of many kernel compartment-specific genes between mmsu and wild-type(WT)kernels,with impaired nutrient accumulation and auxin signaling pathway in the mmsu endosperm.Compared to WT,ZmADT2 mutation led to reduced auxin levels and smaller endosperm cell size.Exogenous auxin rescued the small kernel phenotype of mmsu.Additionally,auxin distribution was reduced in the basal endosperm transfer layer(BETL),causing defects in its development and function,including reduced transfer cell elongation,cell wall ingrowth and nutrient uptake.These findings suggest that ZmADT2 mediated mediates an auxin signaling pathway that is essential for maize kernel development.
基金supported by the National Natural Science Foundation of China(32072126 and 32230075)the Shandong Provincial Natural Science Foundation(ZR2019MC005).
文摘Pentatricopeptide repeat(PPR)proteins are a large group of eukaryote-specific RNA-binding proteins that play pivotal roles in plant organelle gene expression.Here,we report the function of PPR21 in mitochondrial intron splicing and its role in maize kernel development.PPR21 is a typical P-type PPR protein targeted to mitochondria.The ppr21 mutants are arrested in embryogenesis and endosperm development,leading to embryo lethality.Null mutations of PPR21 reduce the splicing efficiency of nad2 intron 1,2,and 4 and impair the assembly and activity of mitochondrial complex I.Previous studies show that the P-type PPR protein EMP12 is required for the splicing of identical introns.However,our protein interaction analyses reveal that PPR21 does not interact with EMP12.Instead,both PPR21 and EMP12 interact with the small MutS-related(SMR)domain-containing PPR protein 1(PPR-SMR1)and the short P-type PPR protein 2(SPR2).PPR-SMR1 interacts with SPR2,and both proteins are required for the splicing of many introns in mitochondria,including nad2 intron 1,2,and 4.These results suggest that a PPR21-(PPR-SMR1/SPR2)-EMP12 complex is involved in the splicing of nad2 introns in maize mitochondria.
基金the National Key Research and Development Program of China(2022YFD1500705)National Natural Science Foundation of China(U19A2035)for financial support。
文摘Strip-till(ST),including straw mulching in the inter-row and localized fertilization in the intra-row,is a conservation tillage system for improving soil quality and crop growth.However,the yield advantage of maize under ST compared to conventional tillage(CT)remains unstable,and the strategies to increase maize yield under ST are unclear.This study aims to understand the physiological mechanism underlining maize yield formation under ST by comparing two maize cultivars,DKM753 and DK517,with contrasting yield performance in ST versus CT systems.Compared to CT,ST resulted in a 4.5%yield increase for DKM753 but a 5.6%decrease for DK517.These yield differences were primarily attributed to variations in grain number per ear(GN).During the rapid growth stage(V14-R3),i.e.,two weeks before and after silking,DKM753 showed a 6.7%increase in maximum growth rate(V_(max))and a 6.3%increase in average growth rate(V)under ST,whereas DK517 exhibited decline of 8.5%in V_(max) and 12.3%in V.Significant positive correlations are observed between V_(max) and V with GN under ST(R^(2)=0.79 and R^(2)=0.90,respectively).Enhanced dry matter accumulation in DKM753 under ST was attributed to increased leaf expansion rates,contributing to a larger photosynthate source.The straw mulching and localized nitrogen fertilization increased root-zone nitrogen availability at silking in ST compared to CT.DKM753 had a greater root system which made better use of the soil N and lead to an increased leaf nitrogen accumulation by 14.9%under ST.It is concluded that maize yield under the strip-till system is determined by grain number per ear,which can be increased by increasing nitrogen accumulation,plant growth,and ear development around silking stage.A sound root system can efficiently utilize soil nitrogen resources under the strip-till system,increasing plant nitrogen accumulation and thereby promoting plant growth.
基金supported by the National Key Research and Development Program of China(2022YFD1200704-3)Crop Varietal Improvement and Insect Pests Control by Nuclear Radiation,the Sichuan Province Science and Technology Program(2022NSFSC0018,2021YFYZ0011,2020YJ0249,MZGC20230108)the Biological Breeding Program of State Key of Sichuan Agricultural University(SKL-ZY202234).
文摘Carotenoids are the largest group of natural pigments responsible for the yellow,orange,and red colors in plant kernels,fruits,and leaves(Gupta and Hirschberg,2021).In plants,carotenoids are involved in manybiological processes,such as acting as accessory light-harvesting pigments in photosynthesis,participating in photoprotection,and serving as precursors for the hormones abscisic acid(ABA)and strigolactones(Ruiz-Sola and Rodriguez-Concepcion,2012).
基金supported by Biological Breeding-National Science and Technology Major Project(2023ZD04069)Young Scientist Project(2023YFD1200008)+2 种基金the National Natural Science Foundation of China(32472122)Sichuan Provincial General Project(24NSFSC1704)the Open Project Program and Biological Breeding Program of State Key Laboratory of Crop Gene Exploration and Utilization in Southwest China(SKL-ZY202211).
文摘Phosphorylation is one of the major posttranslational modifications to control plant growth and development.Opaque2(O2)represents a central hub for endosperm filling,which largely determines seed yield and nutrient storage in maize.However,it still remains unclear how O2 phosphorylation orchestrates endosperm filling and nutrient quality.Here,we systematically identified the phosphorylation sites of O2 during endosperm filling.A total of 18 phosphorylation sites were found in O2 and five sites were identified to apparently modulate its subcellular localization and transactivation capacity.In addition,a conserved protein kinase CK1 was confirmed to interact with and phosphorylate O2 at the residue Threonine(T)202 to promote O2-mediated transactivation and protein stability.Overexpression of CK1 resulted in increased kernel size,100-kernel weight and nutrient storage.Phosphorylation-mimic O2 seeds at T202 exhibited enhanced kernel dimension,test weight,vitreous endosperm area and nutrient accumulation,whereas the phosphorylation-deficient O2 seeds did not.Collectively,this study establishes a comprehensive phosphocode atlas of O2 during endosperm filling and highlights the importance of phosphorylation modification in O2 to precisely orchestrate maize yield and nutrient quality.
基金supported by National Key Research and Development Program of China(2023YFD1200500,2022YFD1201700)the National Natural Science Foundation of China(32071921)+1 种基金Key Research and Development Program of Shandong Province,China(2021LZGC022)the Taishan Scholars Project。
文摘Maize(Zea mays L.)is one of the world's most important staple crops,and is used for manufacturing food,feed,and industrial products.A key factor in maize yield is the grain weight,which directly influences productivity.In this study,we revealed the role of smk23 in maize kernel development.The ethyl methanesulfonate mutant smk23 is characterized by substantially reduced kernel weight.Through map-based cloning,smk23 was found to be located on Chr5 and encode a putative B-type response regulator,Zm RR5.A change from G to A occurs in the coding sequence of Zm RR5,resulting in the early termination of smk23.In Arabidopsis,B-type response regulators are involved in cytokinin signaling.Histological analysis and in situ hybridization of the mutant revealed abnormal endosperm development,particularly in the basal endosperm transfer layer(BETL),a specialized tissue critical for nutrient transport from the maternal tissues to the developing kernel.Zm RR5 positively regulates key genes involved in BETL development and function,including MRP1 and TCRR1.Furthermore,RNA sequencing revealed that several genes closely linked to BETL development,including BETL2,MEG1,and MN1,were significantly downregulated in smk23.These genes are essential for nutrient transport,tissue development and signal transduction.In addition,haploid analysis of Zm RR5 revealed natural variations(Hap 2)that may contribute to the increased kernel yield.Disruption of Zm RR5 function in smk23 leads to defects in BETL development,impairing its ability to transport nutrients,and ultimately resulting in a smaller kernel size.This study provides new insights into the molecular mechanisms through which Zm RR5 regulates maize kernel development and offers potential strategies for improving grain yield.
基金supported by the National Key Research and Development Program of China(2022YFD2300700)the National Natural Science Foundation of China(32201894)+1 种基金Hainan Provincial Natural Science Foundation of China(323QN193)Rothamsted Research receives strategic funding from the Biotechnological and Biological Sciences Research Council of the UK.Matthew J.Paul acknowledges funding from the Delivering Sustainable Wheat(BB/X011003/1)Strategic Program.
文摘Inferior grains exhibit delayed developmental processes and reduced metabolic activities compared to superior grains,leading to unstable rice yield and quality.While significant advancements have been achieved in elucidating the physiology of endosperm filling in inferior grains,the role of the embryo remains underexplored and warrants comprehensive investigation.Two Wuyujing 3 mutants,DW024(relatively synchronous;syn-DW024)and DW179(significantly asynchronous;asyn-DW179),with different grain-filling patterns were used in this study.Samples of superior and inferior grains were collected at intervals from 5 to 60 d after fertilization and subsequently dissected into subsamples of the embryo and endosperm.Histochemical staining,biochemical analysis,and RNA sequencing(RNA-seq)were combined to systematically compare developmental and physiological traits between superior and inferior grains.Combining hierarchical clustering of mRNA datasets revealed three developmental phases of the endosperm and embryo:morphogenesis,endosperm filling/embryo enlargement,and maturation.In both syn-DW024 and asyn-DW179,the duration of the endosperm/embryo morphogenesis phase was identical in superior and inferior grains.The inferior grains of asyn-DW179 exhibited a 10-day prolongation in the endosperm filling phase and a 20-day extension in the embryo enlargement phase compared to the superior grains.The endosperm of inferior grains exhibited higher contents of sugars and free amino acids,along with slower accumulation of storage compounds,which was associated with the down-regulation of genes for starch synthesis and ABA signaling.In addition,transporters for nutrient exchanges between endosperm and embryo were down-regulated,suggesting a potential role of the embryo in adjusting the endosperm filling process.Collectively,our results reveal that the prolonged phases of endosperm filling and embryo enlargement may underlie the impaired development of inferior grains,offering a new perspective for breeding or cultivating rice with uniform grain quality.
基金Supported by the National Natural Science Foundation of China(31201164)the Program of Science and Technology of Education Department of Heilongjiang Province(12521036)+2 种基金China Postdoctoral Science Foundation(2012M511434)Heilongjiang Province Postdoctoral Science Foundation(LBH-Z12036)the Doctoral Starting Up Foundation of Northeast Agricultural University(2012RCB01)
文摘DCPTA （2-diethylaminoethyl-3, 4-dichlorophenylether） is a new plant regulator which can be used to regulate growth and development for crops. Experiments on maize seedlings were conducted in the growth chamber to study the effects of foliar applied DCPTA. The plant pots were placed in a completely randomized design with three replicates. The maize seedlings were treated with 0 mg·L-1 （control）, 20 mg·L-1 and 40 mg·L-1 DCPTA solution. The effects of DCPTA on the photosynthetic characteristics （photosynthesis, stomata conductance, intercellular CO2, and transpiration rate）, related physiological characteristics （contents of soluble sugar and starch）, chlorophyll fluorescence parameters （Fo, Fro, Fv/Fm, Fv/Fo, qP, and qN） and the weight of dry matter in maize seedling were studied. The results showed that DCPTA enhanced photosynthesis of maize seedling. In general, photosynthetic rate in leaves was significantly promoted through spraying DCPTA solution, and 40 rag＂ L~ DCPTA was found to be the best concentration for maize. The relationship between stomata conductance and transpiration rate in maize leaves could be described as linear. With regard to the chlorophyll fluorescence parameters, our fmdings showed that 40 mg·L-1 DCPTA in maize seedling caused an increase in Fm, Fv/Fm, Fm/Fo, qP and a decrease in Fo and qN at some time points checked. It is suggested that DCPTA increased photosynthetic rate by raising both the content of chlorophyll and activities of PSII and the contents of sugar and starch. Compared with the control, the treated maize seedling caused an increase in plant height, root length, shoot dry mass, root dry mass, or the total （root plus shoot） dry mass.
基金supported by the National Natural Science Foundation of China(30070363)the Foundation for Doctorate Research of Ministry of Education,China(200005041).
文摘Morphological variations of the nucleus in starchy endosperm cell were observed by theelectron-transmisson microscope during endosperm development in rice. Along with thedevelopment of the starchy endosperm, the nuclei of the cells showed chromatin condensation,the typical feature of programmed cell death (PCD). The nuclei also showed nucleusdeformation, disruption of nuclear envelope, nucleoplasm leaking into the cytoplasm andnucleus disintegration resulting in nuclear residue formation. From the nucleus deformationto the nucleus disintegration, the morphological changes of the nucleus were orderlyprogressive. This indicated that the cell death of starchy endosperm in rice wasprogrammed cell death. Evans Blue staining observation showed that the cell death wasinitially detected in the central part of starchy endosperm in rice, then expandedoutward. The activities of superoxide dismutase (SOD) and catalase (CAT) in rice starchyendosperm both descended continuously as development progressed. The analysis of DNA ofrice starchy endosperm did not show the presence of DNA laddering. The above resultsshowed that the cell death of starchy endosperm in rice was a special form of PCD.
基金the National Natural Science Foundation of China(32072071)the National Key Research and Development Program of China(2021YFF1000304)。
文摘Chromatin accessibility plays a vital role in gene transcriptional regulation.However,the regulatory mechanism of chromatin accessibility,as well as its role in regulating crucial gene expression and kernel development in maize(Zea mays)are poorly understood.In this study,we isolated a maize kernel mutant designated as defective kernel219(dek219),which displays opaque endosperm and embryo abortion.Dek219 encodes the DICER-LIKE1(DCL1)protein,an essential enzyme in mi RNA biogenesis.Loss of function of Dek219 results in significant reductions in the expression levels of most mi RNAs and histone genes.Further research showed that the Heat shock transcription factor17(Hsf17)-Zm00001d016571 module may be one of the factors affecting the expression of histone genes.Assay results for transposase-accessible chromatin sequencing(ATAC-seq)indicated that the chromatin accessibility of dek219 is altered compared with that of wild type(WT),which may regulate the expression of crucial genes in kernel development.By analyzing differentially expressed genes(DEGs)and differentially accessible chromatin regions(ACRs)between WT and dek219,we identified 119 candidate genes that are regulated by chromatin accessibility,including some reported to be crucial genes for kernel development.Taken together,these results suggest that Dek219 affects chromatin accessibility and the expression of crucial genes that are required for maize kernel development.
基金supported by the State Key Laboratory of North China Crop Improvement and Regulation(NCCIR2022ZZ-4)the Key Research and Development Projects of Hebei Province(21326319D)。
文摘Drought is a main abiotic stress factor hindering plant growth,development,and crop productivity.Therefore,it is crucial to understand the mechanisms by which plants cope with drought stress.Here,the function of the maize peroxidase gene ZmPRX1 in drought stress tolerance was investigated by measurement of its expression in response to drought treatment both in a ZmPRX1 overexpression line and a mutant line.The higher root lignin accumulation and seedling survival rate of the overexpression line than that of the wild type or mutant support a role for ZmPRX1 in maize drought tolerance by regulating root development and lignification.Additionally,yeast one-hybrid,Dule luciferase and ChIP-qPCR assays showed that ZmPRX1 is negatively regulated by a nuclear-localized ZmWRKY86 transcription factor.The gene could potentially be used for breeding of drought-tolerant cultivars.
基金Supported by the National Key Technology R&D Program of China (2011BAD16B11)
文摘With the development of China＇s market economy, the international grain supply situation is increasingly tense, and the grain has been regarded as an important international strategic resource in the international market. Due to the reduction of international grain output and expected inflation, the gap between maize supply shortage and increasing demand is apparent in China, so that China is described as a worrying importer country. By using SWOT analysis belonging to the field of enterprise strategic management, this paper analyzed the current maize industry development in Heilongjiang Province as an entry point, the strength, weakness and opportunity and threat were put forward. Thereby, the developing principles and strategies were proposed to stimulate the maize industry development in Heilongjiang Province, which would lay a good foundation of 50 billion kilograms grain production capacity by 2015 in China, as well as the economic development and local farmers＇ income increase.
基金supported by the Agricultural Science and Technology Innovation Program of CAASthe Research Program of Sanya Yazhou Bay Science and Technology City (SKJC-2020-02-005)the Natural Science Foundation of Jiangsu Province(BK20200288)。
文摘Although several pentatricopeptide repeat(PPR) proteins are involved in post-transcriptional processing of mitochondrial RNA, it is unclear which specific protein is involved in the RNA editing of ccmC in maize(Zea mays). Here we report the identification of the maize empty pericarp 601(emp601) mutant and the map-based cloning of the Emp601 gene, which encodes an E2-type PPR protein that is targeted to mitochondria. A single-nucleotide deletion in the emp601 mutant caused a frameshift and introduced a premature stop codon into the predicted EMP601. This mutation was associated with reduced accumulation of mitochondrial complex Ⅲ as well as with inhibition of growth and differentiation of basal endosperm transfer layer cells, leading to final degeneration of the embryo and endosperm. We determine that loss of EMP601 function prevents the C-to-U RNA editing of the mitochondrial transcript ccmC at position 358.EMP601 binds to the ccmC transcript and directly interacts with Multiple organellar RNA editing factor 8and may be a component of the plant mitochondrial editosome. We conclude that EMP601 functions in RNA editing of mitochondrial ccmC transcripts and influences mitochondrial function and seed development.
基金funded by the National Key Technology R&D Program for Food Production ( 2011BAD16B08)
文摘[ Objective] To investigate the effects of planting date on development and yield of forage maize and to determine the appropriate plant- ing date for forage maize. [ Method] Using forage maize 50 as experimental material, the development of forage maize was observed, and the yield of forage in the later grain filling period and mature stage was measured, after the maize were planted at different dates, r Remltl With the delaying planting date, phenological period was delayed, and the duration of the same growing stage was shortened among different treatments. The shor- test duration days of anthesis maturity period appeared in the treatment of planting in June 15, and the duration days of anthesis maturity period was increased in the treatment of planting in June 30. With the delaying planting date, the height of maize plant in the five leaf stage was increased. The highest plant in the jointing stage appeared in the treatment of planting in June 15. However, the highest plant appeared in the treatment of planting in May 30 after the jointing stage. The number of green leaves per plant was reduced with the delaying planting date in the tasseling stage, and it was increased with the delaying planting date from later grain filling period to mature stage. With the delaying planting date, the fresh matter yield, forage yield and grain yield were reduced. [ Conclusion] The study provides theoretical and practical reference for high-yield cultivation of forage maize.
基金This study was financially supported by the National Natural Science Foundation of China(31801717)the Major Science and Technology Projects in Henan Province,China(221100110300)+2 种基金the Special Fund for Young Talents in Henan Agricultural University,China(30500663)the Opening Foundation of the National Key Laboratory of Crop Science on Wheat and Maize,China(SKL2021KF06)the HAU grant for Collaborative Crop Science Research,China(CCSR2022-1)。
文摘The occurrence, distribution, and rapid molecular detection technology of Heterodera zeae Koshy et al. 1971, have been reported in China. We explored the biological characteristics of H. zeae sampled in Henan Province, China to understand its interaction with plants. Cysts and second-stage juveniles(J2s) were identified under an optical and scanning electron microscope, internal transcribed spacer(ITS) phylogenetic tree, and sequence characterized amplified region(SCAR)-PCR analyses. The optimum hatching temperatures of H. zeae were 30°C and 28°C, with cumulative hatching rates of 16.5 and 16.1%, respectively, at 30 days post-hatching(dph). The hatching rate of H. zeae eggs was improved by 20-and 50-time maize soil leachate and root juice, and 10-time root exudates. The hatching rate in 10-time root exudates was the highest(25.9%). The 10-time root exudates of maize and millet produced the highest hatching rate at 30 dph(25.9 and 22.9%, respectively), followed by wheat(19.9%), barley(18.3%), and rice(17.6%). Heterodera zeae developed faster in maize than in other crops. Fourth-stage juveniles(J4s) were detected in maize roots 8 days post-inoculation(dpi) at 28°C but not in other crops. Combined with hatching tests, the Huang–Huai–Hai summer maize region and the south and central-southwest mountainous maize areas are highly suitable for H. zeae in China. This is the first systematically study of the hatching and infection characteristics on different plant hosts of corn cyst nematode H. zeae in temperate regions. This study laid a theoretical foundation for the rapid spread and high environmental adaptability of corn cyst nematode.
文摘Maize research at Institute for Agricultural Research, Samaru, Nigeria resulted in sustained growth in yields in the last two decades. Maize is grown throughout the country with guinea savanna as the most important maize growing zone. In the last five years, four new open pollinating varieties developed in collaboration with the International Institute of Tropical Agriculture （IITA, Ibadan） had been released for production. Hybrid varieties are also marketed by seed companies. The research was focused on variety improvement, improved management practices, integrated pests and disease control, soil fertility management, on-farm testing of improved production packages and socio-economics of production as well as adoption studies. The recently released quality protein maize has improved the nutritional status of vulnerable groups. Drought tolerant maize for Africa research project has contributed to sustainable maize production, poverty reduction and food security in the continent.
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This work was financially supported in part by grants from National Science and Technology Support Project of China(2016YFD0101205)the Natural Science Foundation of Jiangsu Province,China(BK20160586)+1 种基金National Transgenic Major Project of China(2019ZX08010-004)as well as Six Talent Peaks Project of Jiangsu Province,China(NY-020).
文摘Endosperm mutants are critical to the studies on both starch synthesis and metabolism and genetic improvement of starch quality in maize.In the present study,a novel maize endosperm mutant A0178 of natural variation was used as the experimental material and identified and then characterized.Through phenotypic identification,genetic analysis,main ingredients measurement and embryo rescue,development of genetic mapping population from A0178,the endosperm mutant gene was located.The results showed that the mutant exhibited extremely low germination ability as attributed to the inhibited embryo development,and amounts of sugars were accumulated in the mutant seeds and more sugars content was detected at 23 days after pollination(DAP)in A0178 than B73.Employing genetic linkage analysis,the mutant trait was mapped in the bin 5.04 on chromosome 5.Sequence analysis showed that two sites of base transversion and insertion presented in the protein coding region and non-coding region of the mutant brittle-1(bt1),the adenylate translocator encoding gene involved in the starch synthesis.The single base insertion in the coding region cause frameshift mutation,early termination and lose of function of Brittle-1(BT1).All results suggested that bt1 is a novel allelic gene and the causal gene of this endosperm mutant,providing insights on the mechanism of endosperm formation in maize.
基金supported by the National Natural Science Foundation of China(30070363) the Research Foundation for Doctorate in Universities of China(2000050401).
文摘Ultracytochemical localization of ATPase during development of rice endosperm was performed using a lead phosphate precipitation technique. The results indicated that, at the coenocyte and cellularization stages, active ATPase was mainly distributed in an embryo sac wall, nucleus, and plasma membrane. At the early stage of development and differentiation, active ATPase was observed in the plasma membrane. At the grain filling stage, ATPase was highly active in the plasma membrane, intercellular space, and plasmodesmata in aleurone, moderately active on the plasma membrane in subaleurone. In starchy endosperm, ATPase was localized in the plasma membrane and degenerated nucleus. ATPase activity also appeared around vacuole and protein body in endosperm cell. The relationships between the ultracytochemical localization of ATPase and its function during the development of rice endosperm were discussed. Overall, ATPase was involved in the process of nutrition absorption and protein synthesis.
