The sclerotia of Villosiclava virens were found commonly in high altitude and the temperate regions, where the temperatures are relatively low in rice filling stage. To make sure if low temperature induce the scleroti...The sclerotia of Villosiclava virens were found commonly in high altitude and the temperate regions, where the temperatures are relatively low in rice filling stage. To make sure if low temperature induce the sclerotial formation in V. virens, the inoculated rice panicles in laboratory and the diseased rice panicles cut from paddy fields were treated under different temperatures. The results showed that 3 days of night temperature at 15°C were enough to induce the sclerotial formation. The low temperature was much more effective for young balls with intact membranes. After appearance of chlamydospores on the ball surfaces, the sclerotium could not differentiate anymore. The sclerotia began to differentiate below the chlamydospore layer and gradually grew onto the ball surfaces. This suggests that low temperature in the early development stage of false smut balls is an important factor to induce the sclerotial differentiation, and rice cultivars with long growth periods are able to produce more sclerotium-bearing balls, which will produce mass of spores in paddy field in the coming year.展开更多
Rice with low glutelin content is suitable as functional food for patients affected with diabetes and kidney failure. The fine mapping of the gene(s) responsible for low glutelin content will provide information regar...Rice with low glutelin content is suitable as functional food for patients affected with diabetes and kidney failure. The fine mapping of the gene(s) responsible for low glutelin content will provide information regarding the distribution of glutelin related genes in rice genome and will generate markers for the selection of low glutelin rice varieties. Following an SDS-PAGE screen of rice germplasm from Taihu Valley of China, Japonica selection W3660 is identified to be a novel mutant characterized with low glutelin content. For fine mapping the mutant gene for low glutelin content, F2 and F3 populations were derived from a cross between W3660 and Jingrennuo. SDS-PAGE analysis of the total endosperm protein showed that the low glutelin content trait was controlled by a single dominant nuclear gene. Genetic mapping, using SSRs, located this gene to chromosome 2, in the region between SSR2-001/SSR2-004 and RM1358. The dis- tances of the two markers to the target gene were 1.1 cM and 3.8 cM respectively. By semi-quantitative RT-PCR analysis, the transcripts of GluB4/GluB5 genes located within the region do not change. However, GluB5 gene located proximal to SSR2-001/SSR2-004 was specifically reduced. SSR profiles of seven Japonica varieties were compared with that of W3660 for loci in the relevant genetic region. The markers SSR2-004 and RM1358 were used for marker- assisted selection. The selection efficiencies of SSR2-004 and RM1358 were 96.8% and 92.7% respectively. This provides a standard starting point for the breeding of low glutelin content rice varieties in China.展开更多
Potassium transporters play crucial roles in K^＋ uptake and translocation in plants. However, so far little is known about the regulatory mechanism of potassium transporters. Here, we show that a Shaker-like potassiu...Potassium transporters play crucial roles in K^＋ uptake and translocation in plants. However, so far little is known about the regulatory mechanism of potassium transporters. Here, we show that a Shaker-like potassium channel AtKC1, encoded by the AtLKT1 gene cloned from the Arabidopsis thaliana low-K^＋ （LK）-tolerant mutant Atlktl, significantly regulates AKTl-mediated K^＋ uptake under LK conditions. Under LK conditions, the Atkcl mutants maintained their root growth, whereas wild-type plants stopped their root growth. Lesion of AtKC1 significantly enhanced the tolerance of the Atkcl mutants to LK stress and markedly increased K^＋ uptake and K^＋ accumulation in the Atkclmutant roots under LK conditions. Electrophysiological results showed that AtKC1 inhibited the AKT1-mediated inward K^＋ currents and negatively shifted the voltage dependence of AKT1 channels. These results demonstrate that the ‘silent＇ K^＋ channel α-subunit AtKC1 negatively regulates the AKTl-mediated K^＋ uptake in Arabidopsis roots and consequently alters the ratio of root-to-shoot under LK stress conditions.展开更多
A research study was carried out to determine the electrical conductivity （EC）, residual sodium carbonate （RSC）, sodium adsorption ratio （SAR）, pH and metals in metal-polluted irrigation water from a nullah and ...A research study was carried out to determine the electrical conductivity （EC）, residual sodium carbonate （RSC）, sodium adsorption ratio （SAR）, pH and metals in metal-polluted irrigation water from a nullah and those in soils over a period of time, and the effect of metals on rice yield and metal concentrations in rice grain and straw. Two sites （I and If） were selected on the bank of Nullah Dek at Thatta Wasiran in Sheikhupura District （Pakistan）, with two rice varieties, Super Basmati and Basmati 385, at both sites. Water samples were collected during rice crop growth at 15-day intervals from August 3 to November 1, 2002. The results showed that Nullah Dek water had an EC 〉1.0 dS m^-1 and RSC of 2.78-4.11 mmolc L^-1, which was hazardous for crops, but the SAR was within the safe limit. Cu, Mn Cd and Sr were also within safe limits. The soil analysis showed that Site Ⅱ was free from salinity/sodicity, whereas Site Ⅰ was saline sodic. Among metals, Zn was sometimes deficient, Cu, Mn and Fe were adequate, and St, Ni and Cd were within safe limits in the soil at both the sites. After the rice crop harvest, concentrations of all metals tested were usually slightly increased, being higher in the upper soil layer than the lower. In addition, Basmati 385 produced higher rice grain and straw yield than Super Basmati. Chemical analysis of rice grain indicated the presence of Zn, Cu, Fe, Mn, Pb and Sr, whereas rice straw contained Zn, Cu, Fe, Mn and Sr, with Cd and Ni both being found in minute quantities.展开更多
Kenaf （Hibiscus cannabinus L.） is one of the most economically important crops for non-wood fiber production. The objective of this study was to establish a genetic linkage map of kenaf with higher density of molecu...Kenaf （Hibiscus cannabinus L.） is one of the most economically important crops for non-wood fiber production. The objective of this study was to establish a genetic linkage map of kenaf with higher density of molecular markers. A semi- wild variety Ga42 and a cultivar Alain kenaf were used as parents to construct an F2 population consisting of 155 plants. The genetic linkage map comprising 134 marker loci was constructed, including 65 sequence-related amplified polymorphism （SRAP）, 56 inter-simple sequence repeat （ISSR）, and 13 randomly amplified polymorphic DNA （RAPD） markers. This map spans 2 108.9 cM and contains 20 linkage groups with an average marker density of 15.7 cM between the adjacent markers.展开更多
Since maize is one of the most important cereal crops in the world,establishment of an efficient genetic transformation system is critical for its improvement.In the current study,several elite corn lines were tested ...Since maize is one of the most important cereal crops in the world,establishment of an efficient genetic transformation system is critical for its improvement.In the current study,several elite corn lines were tested for suitability of Agrobacterium tumefaciens-mediated transformation by using immature embryos as explants.Infection ability and efficiency of transformation of A.tumefaciens sp.strains EHA105 and LBA4404,different heat treatment times of immature embryos before infection,influence of L-cysteine addition in co-cultivation medium after transformation,and how different ways of selection and cultivation influence the efficiency of transformation were compared.Glyphosate-resistant gene 2mG2-EPSPS was transformed into several typical maize genotypes including 78599,Zong 31 and BA,under the optimum conditions.Results showed that the hypervirulent Agrobacterium tumefaciens sp.strain EHA105 was more infectious than LBA4404.Inclusion of L-cysteine（100 mg L-1） in co-cultivation medium,and heating of the immature embryos for 3 min prior to infection led to a significant increase in the transformation efficiency.Growth in resting medium for 4-10 d and delaying selection was beneficial to the survival of resistant calli.During induction of germination,adding a high concentration of 6-BA（5 mg L-1） and a low concentration of 2,4-D（0.2 mg L-1） to regeneration medium significantly enhanced germination percentage.Using the optimized transformation procedure,more than 800 transgenic plants were obtained from 78599,Zong 31 and BA.By spraying herbicide glyphosate on leaves of transgenic lines,we identified 66 primary glyphosate-resistant plants.The transformation efficiency was 8.2%.PCR and Southern-blot analyses confirmed the integration of the transgenes in the maize genome.展开更多
Some winter wheat varieties were selected in this experiment. The results were as follows： 1） Leaf orientation value （LOV） and leaf area index （LAI） of wheat had different contributions to canopy spectral reflec...Some winter wheat varieties were selected in this experiment. The results were as follows： 1） Leaf orientation value （LOV） and leaf area index （LAI） of wheat had different contributions to canopy spectral reflectance （CSR）. For example, LOV affected greatly canopy spectra more than LAI did in jointing stage, but LAI had a greater effect on CSR than LOV did after the ground was near to be covered completely. 2） Twenty treatments including different varieties and densities were arranged in this experiment, and the result of cluster analysis showed that all these treatments can be parted into four clusters according to LAI and LOV： varieties with erect leaves and low LAI （denoted as A）, varieties with erect leaves and high LAI （denoted as B）, varieties with horizontal leaves and low LAI （denoted as C）, varieties with horizontal leaves and high LAI （denoted as D）. Their CSR had difference in 400-700 nm and 700-1 150 nm at jointing stage, especially in different plant types. 3） There was obvious distribution difference among different clusters in scatter plot （X=△R890, Y=R890）, △R890 was the reflectance increment from jointing to booting stage. It was seen from the Y-axis direction that R890 of horizontal varieties were higher than the erect ones, and seen from the X-axis direction that the greater △R890 was, the lower LAI one within the same plant type varieties, which indicted that the combination of plant-type and the population magnitude can be initially identified by this method.展开更多
Integrative physical mapping is the centerpieceof and essential for advanced genomics research.Upland cotton(Gossypium hirsutum L.)geneticstandard line TM-1 is used as the referencegenotype to develop a whole-genome,B...Integrative physical mapping is the centerpieceof and essential for advanced genomics research.Upland cotton(Gossypium hirsutum L.)geneticstandard line TM-1 is used as the referencegenotype to develop a whole-genome,BAC/BIBAC-based integrated physical/genetic map ofthe cotton genome.From the TM-1 line we haveconstructed two BAC libraries with HindIII展开更多
Genes are continually being created by the processes of genome duplication （ohnolog） and gene duplication （paralog）. Whole-genome duplications have been found to be widespread in plant species and play an importan...Genes are continually being created by the processes of genome duplication （ohnolog） and gene duplication （paralog）. Whole-genome duplications have been found to be widespread in plant species and play an important role in plant evolution. Clearly un-overlapping duplicated blocks of whole-genome duplications can be detected in the genome of sequenced rice （Oryza sativa）. Syntenic ohnolog pairs （ohnologues） of the whole-genome duplications in rice were identified based on their syntenic duplicate lines. The paralogs of ohnologues were further scanned using multi-round reciprocal BLAST best-hit searching （E〈e^-14）. The results indicated that an average of 0.55 sister paralogs could be found for every ohnologue in rice. These results suggest that small-scale duplications, as well as whole-genome duplications, play a significant role in the two duplicated rice genomes.展开更多
Interspecific introgression contributessignificantly to genetic improvement of cotton(Gossypium hirsutum L.).Cytogenetics hasfigured prominently in the creation ofinterspecific hybrids,synthetic polyploids,backcrosses...Interspecific introgression contributessignificantly to genetic improvement of cotton(Gossypium hirsutum L.).Cytogenetics hasfigured prominently in the creation ofinterspecific hybrids,synthetic polyploids,backcrosses,and other stocks essential to early-and mid-stage manipulation of germplasm展开更多
Nitrogen(N)is one of the basic nutrients and signals for plant development and deficiency of it would always limit the productions of crops in the field.Quantitative research on expression of N-stress responsive prote...Nitrogen(N)is one of the basic nutrients and signals for plant development and deficiency of it would always limit the productions of crops in the field.Quantitative research on expression of N-stress responsive proteins on a proteome level remains elusive.In order to gain a deep insight into the proteins responding to nitrogen stress in rapeseed(Brassica napus L.),comparative proteomic analysis was performed to investigate changes of protein expression profiles from the root,stem and leaf under different N concentrations,respectively.More than 200 differential abundance proteins(DAPs)were detected and categorized into groups according to annotations,including“binding and catalytic activity”,“involved in primary metabolism and cellular processes”,“stress-response”and so on.Variation in chlorophyll(Chl)content and antioxidant activities further revealed that oxidative stress raised with the increase of N concentration.Bioinformatics analysis based on the expression level of total proteins suggested these DAPs might play important roles in adaptation to N-stress conditions.Generally,these results provides a new aspect into N-stress responding proteins in Brassica plants.展开更多
The identification of loci and markers associated with milled grain appearance traits is essential for breeding high-yielding and good-quality rice variety.To detect stable loci for these characteristics,grain length(...The identification of loci and markers associated with milled grain appearance traits is essential for breeding high-yielding and good-quality rice variety.To detect stable loci for these characteristics,grain length(GL),grain width(GW),grain length/width(GLW),chalkiness degree(CD),chalky-grain rate(CR)and translucency degree(TD)of 378 rice lines were evaluated in three seasons.These lines were derived from a multi-parent advanced generation intercross(MAGIC)population.展开更多
Soybean (Glycine max L. Merr.) adaptation to new environments has been hard to predict based on maturity group. The aim of this study was to evaluate the performance of 14 soybean genotypes, from the Soybean Breeding ...Soybean (Glycine max L. Merr.) adaptation to new environments has been hard to predict based on maturity group. The aim of this study was to evaluate the performance of 14 soybean genotypes, from the Soybean Breeding Program of the Federal University of Uberlandia, in their adaptive capacity and seed yield stability at 3 locations and 2 growing seasons. For the adaptability and stability analysis the Toler and Centroid methods were used;5 genotypic groups were identified in the first whereas 4 groups were identified in the latter. By the Toler method group A was composed by 4 genotypes, UFU-001, UFU-003, UFU-0010, and UFU-001. They showed a convex pattern of adaptability and stability. In contrast, the genotypes UFU-008 and UFU-0013 were classified in Group E with a concave pattern of adaptability and stability. Regarding results from the Centroid method, the Genotype UFU-002, with higher seed yield than average, was the only genotype in Ideotype VI with moderate adaptability to favorable environments. In contrast, 10 genotypes were included in the Ideotype V, of medium general adaptability. The genotypes UFU-001, UFU-002, UFU-006, UFU-0010, and UFU-0011 were recommended for use in the Brazilian Cerrado growing region. These genotypes had high seed yield potential in high quality environments.展开更多
Soil amendments containing carbonized materials increase the soil carbon reservoir,influence plant productivity,and,ultimately,help to clean the environment.There is data on the effect of such additions on soil physic...Soil amendments containing carbonized materials increase the soil carbon reservoir,influence plant productivity,and,ultimately,help to clean the environment.There is data on the effect of such additions on soil physicochemical properties or plant growth,but few studies have focused on how these carbonized materials are distributed by termite species in the soil ecosystem.It is the first comprehensive study of the transportation of biochar(BC)by termite species under tropical environmental conditions in Pakistan.The present study was carried out to test the hypothesis that if termite species I)were involved in the distribution of biochar particles II)if yes,then how far these particles were transported during the study period(10 days)and III)check their preference between the enriched BC(EBC)and non-enriched BC.BC was enriched with the cattle slurry after its pyrolysis in the study.The results showed that EBC particles were significantly more widely distributed than non-enriched BC particles,but both types of BC were transported more than 4 cm(ring 4)within 10 days(at the end of the experiment).The current study also revealed that EBC was easily attached to the setae,cuticle,and legs of termites,implying that it could potentially be transported over a greater distance.Furthermore,transportation of EBC over larger distances indicated a potential preference of termite species between the EBC and BC particles.During the study,however,the preference among the termite species was also observed.Under the prevailing study conditions,the Coptotermes heimi and Heteroterme indicola species transported the EBC further than Microtermes obesi and Odontotermes obesus.These findings revealed that transportation preferences were observed among the four termite species.In conclusion,the current study found that termites were involved in the distribution of BC particles,with a preference for EBC and that these have the potential to transport BC particles more than 4 cm within 10 days.Furthermore,two species Coptotermes heimi and Heteroterme indicola may be more suitable candidates for EBC transpiration in Pakistani soils.It was necessary to conduct additional research into the effect of temperature on the transportation process.展开更多
Super Absorbent Polyacrylate (SAP) hydrogels absorb and store water thereby aiding plant establishment when incurporated in the soil. The effect of cross-linked SAP hydrogel amendment on the performance of tree seedli...Super Absorbent Polyacrylate (SAP) hydrogels absorb and store water thereby aiding plant establishment when incurporated in the soil. The effect of cross-linked SAP hydrogel amendment on the performance of tree seedlings of Picea abies, Pinus sylivestris and Fagus sylvatica grown in temperate soils under water stress and non-water stress periods was investigated in a green house. The objective was to compare the root and shoot biomass of seedlings of the three species grown in sand, loam and clay soils amended with 0.4% w/w hydrogel in non water stress conditions as well as survival, root and shoot biomass after subjection to water stress. The seedlings were grown for 16 weeks, harvested and shoot as well as root biomass determined before water stress. The seedlings were also subjected to water stress and their biomass assessed at death following the water stress. The results showed that root and shoot biomass were generally higher in hydrogel amended soils compared to the controls. Root and shoot biomass of Fagus sylvatica was lower compared to Picea abies and Pinus sylivestris before water stress. The 0.4% hydrogel amendment significantly increased species’ survival in the different soils studied. Although root biomass was higher in hydrogel amended sandy soil compared to other soils, P. sylivestris and F. sylvatica shoot biomass were higher in hydrogel amended clay and loam soils compared to the sandy soil after water stress. Biomass was higher in sand compared to loam and clay soils under non-water and water stressed conditions. Since SAP hydrogel amendment improved the survival and biomass production of tree seedlings before and after water stress, use of SAPs could be promoted to enhance seedling production in water stress and non-water stress environments.展开更多
Weeds cause tremendous economic and ecological damage worldwide.The number of genomes established for weed species has sharply increased during the recent decade,with some 26 weed species having been sequenced and de ...Weeds cause tremendous economic and ecological damage worldwide.The number of genomes established for weed species has sharply increased during the recent decade,with some 26 weed species having been sequenced and de novo genomes assembled.These genomes range from 270 Mb(Barbarea vulgaris)to almost 4.4 Gb(Aegilops tauschii).Importantly,chromosome-level assemblies are now available for 17 of these 26 species,and genomic investigations on weed populations have been conducted in at least 12 species.The resulting genomic data have greatly facilitated studies of weed management and biology,especially origin and evolution.Available weed genomes have indeed revealed valuable weed-derived genetic materials for crop improvement.In this review,we summarize the recent progress made in weed genomics and provide a perspective for further exploitation in this emerging field.展开更多
Drought resistance is required in rice breeding to address the challenge of frequent droughts . However, the evolutionary mechanism of rice drought resistance is not fully understood. We investigated the genetic diffe...Drought resistance is required in rice breeding to address the challenge of frequent droughts . However, the evolutionary mechanism of rice drought resistance is not fully understood. We investigated the genetic differentiation between upland and lowland rice domesticated in agro-ecosystems with contrasting water-soil conditions using genome-wide SNPs. We estimated morphological differences among upland and lowland rice in drought resistance and productivity through common garden experiments. Upland rice had better drought resistance but poorer productivity. The negative correlations between traits of drought resistance and productivity are attributed to the underlying genetic trade-offs through tight linkages (e.g., DCA1 and OsCesA7) or pleiotropic effects (e.g., LAX1). The genetic trade-offs are comm on and greatly shape the evolutio n of drought resista nee in upland rice . In genomic regions associated with both productivity and drought resistance, signs of balancing selection were detected in upland rice, while signs of directional selection were detected in lowland rice, potentially contributing to their adaptive differentiation. Signs of balancing selection in upland rice resulted from bi-directional selection during its domestication in drought-prone upland agro-ecosystems.Using genome-wide association analysis, we ide ntified several valuable quantitative trait loci associated with drought resista nee, for which highly differentiated genes should be considered candidates. Bi-directional selection breaking tight linkages by accumulating recombination events would be applicable in breeding water-saving and droughtresistance rice.展开更多
Soil microbes are one of the most important determinants of allelopathic effects in the field. However, most studies testing the role of allelopathy in biological invasions did not consider the roles of soil microbes....Soil microbes are one of the most important determinants of allelopathic effects in the field. However, most studies testing the role of allelopathy in biological invasions did not consider the roles of soil microbes. Here we tested the hypothesis that soil microbes which can degrade allelochemicals may accumulate in soils over time by adaptation and therefore increase the degradation of allelochemicals and alleviate the allelopathic effects in biological invasions. As expected, soil microbes signifi- cantly decreased the allelopathic effects of leaf leachates of eight in the nine invasive plant species studied. In addition, Ageratina adenophora showed lower allelopathic effects in soil with long or intermediately invasion history than those in soil with short invasion history. The two main allelo- chemicals of the invader were degraded more rapidly with increasing invasion history in the soil. Correspondingly,biomass and activity of the soil microbes were higher in the soils with long invasion history than in that with short invasion history. Our results indicate that soil microbes may graduaUy adapt to the allelochemicals of Ageratina and alleviate its allelopathic effects and thus support the above hypothesis. It is necessary to consider the effects of soil microbes when testing the roles of allelopathy or the novel weapons hypothesis in biological invasions.展开更多
Phosphorus(P)is essential for life and for efficient crop production,but global P use with limited recycling is inefficient in several sectors,including agronomy.Unfortunately,plant physiologists,agronomists,farmers a...Phosphorus(P)is essential for life and for efficient crop production,but global P use with limited recycling is inefficient in several sectors,including agronomy.Unfortunately,plant physiologists,agronomists,farmers and end users employ different measures for P use efficiency(PUE),which often masks their values at different scales.The term P use effectiveness,which also considers energetic and sustainability measures in addition to P balances,is also a valuable concept.Major physiological and genetic factors for plant P uptake and utilization have been identified,but there has been limited success in genetically improving PUE of modern crop cultivars.In maize,studies on root architectural and morphological traits appear promising.Rhizosphere processes assist in mobilizing and capturing sparingly soluble phosphate from rock phosphate.Combinations of phosphate-solubilizing microorganisms with ammonium-based nitrogen fertilizer,as well as strategies of fertilizer placement near the roots of target crops,can moderately enhance PUE.The desired concentration of P in the products differs,depending on the final use of the crop products as feed,food or for energy conversion,which should be considered during crop production.展开更多
Dear Editor,Many functional characteristics of plant tissue attribute to highly specialized cells in the tissue.Dissecting cell types and profiling the transcriptome and proteome of individual cell types of plant tiss...Dear Editor,Many functional characteristics of plant tissue attribute to highly specialized cells in the tissue.Dissecting cell types and profiling the transcriptome and proteome of individual cell types of plant tissues are important for understanding cellular activities underlying plant development and stress adaptation(Shaw et al.,2021).Single-cell RNA sequencing(scRNA-seq)provides such a tool for studying the transcriptional activities of individual cell types at single-cell resolution in any given organism(Rich-Griffin et al.,2020).展开更多
基金financially supported by the National Natural Science Foundation of China(31271999)the Special Fund for Agro-scientific Research in the Public Interest,China(200903039-5)
文摘The sclerotia of Villosiclava virens were found commonly in high altitude and the temperate regions, where the temperatures are relatively low in rice filling stage. To make sure if low temperature induce the sclerotial formation in V. virens, the inoculated rice panicles in laboratory and the diseased rice panicles cut from paddy fields were treated under different temperatures. The results showed that 3 days of night temperature at 15°C were enough to induce the sclerotial formation. The low temperature was much more effective for young balls with intact membranes. After appearance of chlamydospores on the ball surfaces, the sclerotium could not differentiate anymore. The sclerotia began to differentiate below the chlamydospore layer and gradually grew onto the ball surfaces. This suggests that low temperature in the early development stage of false smut balls is an important factor to induce the sclerotial differentiation, and rice cultivars with long growth periods are able to produce more sclerotium-bearing balls, which will produce mass of spores in paddy field in the coming year.
基金supported by the grants from Hi-Tech Research and Development Program of China("863"Program,No.2003AA222131,2003AA207020)the National Natural Science Foundation of China(No.30170570)Special Program for gene-transfering(No.JY03-B-07,JY03-A-07-02)
文摘Rice with low glutelin content is suitable as functional food for patients affected with diabetes and kidney failure. The fine mapping of the gene(s) responsible for low glutelin content will provide information regarding the distribution of glutelin related genes in rice genome and will generate markers for the selection of low glutelin rice varieties. Following an SDS-PAGE screen of rice germplasm from Taihu Valley of China, Japonica selection W3660 is identified to be a novel mutant characterized with low glutelin content. For fine mapping the mutant gene for low glutelin content, F2 and F3 populations were derived from a cross between W3660 and Jingrennuo. SDS-PAGE analysis of the total endosperm protein showed that the low glutelin content trait was controlled by a single dominant nuclear gene. Genetic mapping, using SSRs, located this gene to chromosome 2, in the region between SSR2-001/SSR2-004 and RM1358. The dis- tances of the two markers to the target gene were 1.1 cM and 3.8 cM respectively. By semi-quantitative RT-PCR analysis, the transcripts of GluB4/GluB5 genes located within the region do not change. However, GluB5 gene located proximal to SSR2-001/SSR2-004 was specifically reduced. SSR profiles of seven Japonica varieties were compared with that of W3660 for loci in the relevant genetic region. The markers SSR2-004 and RM1358 were used for marker- assisted selection. The selection efficiencies of SSR2-004 and RM1358 were 96.8% and 92.7% respectively. This provides a standard starting point for the breeding of low glutelin content rice varieties in China.
基金Acknowledgments We thank Dr Emily Liman （University of Southern California, USA） for providing the pGEMHE vector for the Xenopus oocyte experiments. We also thank Dr Richer Gaber （Northwestern Uni- versity, USA） for providing the yeast mutant strain with K＋ transport deficiency. We are grateful to Dr Rainer Hedrich （University of Wurzburg, Germany） for critical discussion. This work was supported by the National Natural Science Foundation of China （grant no. 30830013 to WHW）, the Beijing Municipal Education Commission （grant no. YB20081001901 to WHW） and the Program of Introducing Talents of Discipline to Universities （grant no. B06003 to WHW）.
文摘Potassium transporters play crucial roles in K^＋ uptake and translocation in plants. However, so far little is known about the regulatory mechanism of potassium transporters. Here, we show that a Shaker-like potassium channel AtKC1, encoded by the AtLKT1 gene cloned from the Arabidopsis thaliana low-K^＋ （LK）-tolerant mutant Atlktl, significantly regulates AKTl-mediated K^＋ uptake under LK conditions. Under LK conditions, the Atkcl mutants maintained their root growth, whereas wild-type plants stopped their root growth. Lesion of AtKC1 significantly enhanced the tolerance of the Atkcl mutants to LK stress and markedly increased K^＋ uptake and K^＋ accumulation in the Atkclmutant roots under LK conditions. Electrophysiological results showed that AtKC1 inhibited the AKT1-mediated inward K^＋ currents and negatively shifted the voltage dependence of AKT1 channels. These results demonstrate that the ‘silent＇ K^＋ channel α-subunit AtKC1 negatively regulates the AKTl-mediated K^＋ uptake in Arabidopsis roots and consequently alters the ratio of root-to-shoot under LK stress conditions.
基金Project supported by the World Wide Fund for Nature Pakistan (WWF-Pakistan).
文摘A research study was carried out to determine the electrical conductivity （EC）, residual sodium carbonate （RSC）, sodium adsorption ratio （SAR）, pH and metals in metal-polluted irrigation water from a nullah and those in soils over a period of time, and the effect of metals on rice yield and metal concentrations in rice grain and straw. Two sites （I and If） were selected on the bank of Nullah Dek at Thatta Wasiran in Sheikhupura District （Pakistan）, with two rice varieties, Super Basmati and Basmati 385, at both sites. Water samples were collected during rice crop growth at 15-day intervals from August 3 to November 1, 2002. The results showed that Nullah Dek water had an EC 〉1.0 dS m^-1 and RSC of 2.78-4.11 mmolc L^-1, which was hazardous for crops, but the SAR was within the safe limit. Cu, Mn Cd and Sr were also within safe limits. The soil analysis showed that Site Ⅱ was free from salinity/sodicity, whereas Site Ⅰ was saline sodic. Among metals, Zn was sometimes deficient, Cu, Mn and Fe were adequate, and St, Ni and Cd were within safe limits in the soil at both the sites. After the rice crop harvest, concentrations of all metals tested were usually slightly increased, being higher in the upper soil layer than the lower. In addition, Basmati 385 produced higher rice grain and straw yield than Super Basmati. Chemical analysis of rice grain indicated the presence of Zn, Cu, Fe, Mn, Pb and Sr, whereas rice straw contained Zn, Cu, Fe, Mn and Sr, with Cd and Ni both being found in minute quantities.
基金supported by the National Natural Science Fundation of China (30571188 and 31000734)the National Agri-Industry Technology Research System for Crops of Bast and Leaf Fiber, China (nycytx-19-E05)the Construction of Germplasm Resources Platform for Bast Fiber Crops in Fujian, China (2010N2002)
文摘Kenaf （Hibiscus cannabinus L.） is one of the most economically important crops for non-wood fiber production. The objective of this study was to establish a genetic linkage map of kenaf with higher density of molecular markers. A semi- wild variety Ga42 and a cultivar Alain kenaf were used as parents to construct an F2 population consisting of 155 plants. The genetic linkage map comprising 134 marker loci was constructed, including 65 sequence-related amplified polymorphism （SRAP）, 56 inter-simple sequence repeat （ISSR）, and 13 randomly amplified polymorphic DNA （RAPD） markers. This map spans 2 108.9 cM and contains 20 linkage groups with an average marker density of 15.7 cM between the adjacent markers.
基金supported by the National Key Project of transgenic varieties breeding(2009ZX08003-003B)the Light of West Talent Training Project of China(2010-2011)the Project of Sichuan Province Finance Genetic Engineering,China(2011JYGC01-002)
文摘Since maize is one of the most important cereal crops in the world,establishment of an efficient genetic transformation system is critical for its improvement.In the current study,several elite corn lines were tested for suitability of Agrobacterium tumefaciens-mediated transformation by using immature embryos as explants.Infection ability and efficiency of transformation of A.tumefaciens sp.strains EHA105 and LBA4404,different heat treatment times of immature embryos before infection,influence of L-cysteine addition in co-cultivation medium after transformation,and how different ways of selection and cultivation influence the efficiency of transformation were compared.Glyphosate-resistant gene 2mG2-EPSPS was transformed into several typical maize genotypes including 78599,Zong 31 and BA,under the optimum conditions.Results showed that the hypervirulent Agrobacterium tumefaciens sp.strain EHA105 was more infectious than LBA4404.Inclusion of L-cysteine（100 mg L-1） in co-cultivation medium,and heating of the immature embryos for 3 min prior to infection led to a significant increase in the transformation efficiency.Growth in resting medium for 4-10 d and delaying selection was beneficial to the survival of resistant calli.During induction of germination,adding a high concentration of 6-BA（5 mg L-1） and a low concentration of 2,4-D（0.2 mg L-1） to regeneration medium significantly enhanced germination percentage.Using the optimized transformation procedure,more than 800 transgenic plants were obtained from 78599,Zong 31 and BA.By spraying herbicide glyphosate on leaves of transgenic lines,we identified 66 primary glyphosate-resistant plants.The transformation efficiency was 8.2%.PCR and Southern-blot analyses confirmed the integration of the transgenes in the maize genome.
基金the National 863 Programof China(2002AA243011,2003AA209011).
文摘Some winter wheat varieties were selected in this experiment. The results were as follows： 1） Leaf orientation value （LOV） and leaf area index （LAI） of wheat had different contributions to canopy spectral reflectance （CSR）. For example, LOV affected greatly canopy spectra more than LAI did in jointing stage, but LAI had a greater effect on CSR than LOV did after the ground was near to be covered completely. 2） Twenty treatments including different varieties and densities were arranged in this experiment, and the result of cluster analysis showed that all these treatments can be parted into four clusters according to LAI and LOV： varieties with erect leaves and low LAI （denoted as A）, varieties with erect leaves and high LAI （denoted as B）, varieties with horizontal leaves and low LAI （denoted as C）, varieties with horizontal leaves and high LAI （denoted as D）. Their CSR had difference in 400-700 nm and 700-1 150 nm at jointing stage, especially in different plant types. 3） There was obvious distribution difference among different clusters in scatter plot （X=△R890, Y=R890）, △R890 was the reflectance increment from jointing to booting stage. It was seen from the Y-axis direction that R890 of horizontal varieties were higher than the erect ones, and seen from the X-axis direction that the greater △R890 was, the lower LAI one within the same plant type varieties, which indicted that the combination of plant-type and the population magnitude can be initially identified by this method.
文摘Integrative physical mapping is the centerpieceof and essential for advanced genomics research.Upland cotton(Gossypium hirsutum L.)geneticstandard line TM-1 is used as the referencegenotype to develop a whole-genome,BAC/BIBAC-based integrated physical/genetic map ofthe cotton genome.From the TM-1 line we haveconstructed two BAC libraries with HindIII
基金the National NaturalSciencc Foundation of China (90208022,30471067) IBM Shared University Research (LifeScience).
文摘Genes are continually being created by the processes of genome duplication （ohnolog） and gene duplication （paralog）. Whole-genome duplications have been found to be widespread in plant species and play an important role in plant evolution. Clearly un-overlapping duplicated blocks of whole-genome duplications can be detected in the genome of sequenced rice （Oryza sativa）. Syntenic ohnolog pairs （ohnologues） of the whole-genome duplications in rice were identified based on their syntenic duplicate lines. The paralogs of ohnologues were further scanned using multi-round reciprocal BLAST best-hit searching （E〈e^-14）. The results indicated that an average of 0.55 sister paralogs could be found for every ohnologue in rice. These results suggest that small-scale duplications, as well as whole-genome duplications, play a significant role in the two duplicated rice genomes.
文摘Interspecific introgression contributessignificantly to genetic improvement of cotton(Gossypium hirsutum L.).Cytogenetics hasfigured prominently in the creation ofinterspecific hybrids,synthetic polyploids,backcrosses,and other stocks essential to early-and mid-stage manipulation of germplasm
基金funded by Modern Agro-Industry Technology Research System of China(CARS-12)Independent Innovation Project of SAAS(2022ZZCX004)+5 种基金1+9 Open Competition Project of SAAS(1+9KJGG002,1+9KJGG001)the Accurate Identification Project of Crop Germplasm from Sichuan Provincial Finance DepartmentSichuan Science and Technology Program(2022ZDZX0015)Sichuan Crop Breeding Community(2021YFYZ0018)Disciplinary Construction Project for Modern Agriculture in SAAS(2021XKJS003)Chengdu Science and Technology Project(2021-YF09-00062-SN).
文摘Nitrogen(N)is one of the basic nutrients and signals for plant development and deficiency of it would always limit the productions of crops in the field.Quantitative research on expression of N-stress responsive proteins on a proteome level remains elusive.In order to gain a deep insight into the proteins responding to nitrogen stress in rapeseed(Brassica napus L.),comparative proteomic analysis was performed to investigate changes of protein expression profiles from the root,stem and leaf under different N concentrations,respectively.More than 200 differential abundance proteins(DAPs)were detected and categorized into groups according to annotations,including“binding and catalytic activity”,“involved in primary metabolism and cellular processes”,“stress-response”and so on.Variation in chlorophyll(Chl)content and antioxidant activities further revealed that oxidative stress raised with the increase of N concentration.Bioinformatics analysis based on the expression level of total proteins suggested these DAPs might play important roles in adaptation to N-stress conditions.Generally,these results provides a new aspect into N-stress responding proteins in Brassica plants.
基金supported by the earmarked fund for China Agriculture Research System(Grant No.CARS-01)Young Elite Scientists Sponsorship Program by China Association for Science and Technology(Grant No.2020QNRC001)Hunan Academy of Agricultural Sciences Scientific and Technological Innovation Project,China(Grant No.2017JC10)。
文摘The identification of loci and markers associated with milled grain appearance traits is essential for breeding high-yielding and good-quality rice variety.To detect stable loci for these characteristics,grain length(GL),grain width(GW),grain length/width(GLW),chalkiness degree(CD),chalky-grain rate(CR)and translucency degree(TD)of 378 rice lines were evaluated in three seasons.These lines were derived from a multi-parent advanced generation intercross(MAGIC)population.
文摘Soybean (Glycine max L. Merr.) adaptation to new environments has been hard to predict based on maturity group. The aim of this study was to evaluate the performance of 14 soybean genotypes, from the Soybean Breeding Program of the Federal University of Uberlandia, in their adaptive capacity and seed yield stability at 3 locations and 2 growing seasons. For the adaptability and stability analysis the Toler and Centroid methods were used;5 genotypic groups were identified in the first whereas 4 groups were identified in the latter. By the Toler method group A was composed by 4 genotypes, UFU-001, UFU-003, UFU-0010, and UFU-001. They showed a convex pattern of adaptability and stability. In contrast, the genotypes UFU-008 and UFU-0013 were classified in Group E with a concave pattern of adaptability and stability. Regarding results from the Centroid method, the Genotype UFU-002, with higher seed yield than average, was the only genotype in Ideotype VI with moderate adaptability to favorable environments. In contrast, 10 genotypes were included in the Ideotype V, of medium general adaptability. The genotypes UFU-001, UFU-002, UFU-006, UFU-0010, and UFU-0011 were recommended for use in the Brazilian Cerrado growing region. These genotypes had high seed yield potential in high quality environments.
基金the Researchers Supporting Project No.(RSP-2021/298),King Saud University,Riyadh,Saudi Arabia。
文摘Soil amendments containing carbonized materials increase the soil carbon reservoir,influence plant productivity,and,ultimately,help to clean the environment.There is data on the effect of such additions on soil physicochemical properties or plant growth,but few studies have focused on how these carbonized materials are distributed by termite species in the soil ecosystem.It is the first comprehensive study of the transportation of biochar(BC)by termite species under tropical environmental conditions in Pakistan.The present study was carried out to test the hypothesis that if termite species I)were involved in the distribution of biochar particles II)if yes,then how far these particles were transported during the study period(10 days)and III)check their preference between the enriched BC(EBC)and non-enriched BC.BC was enriched with the cattle slurry after its pyrolysis in the study.The results showed that EBC particles were significantly more widely distributed than non-enriched BC particles,but both types of BC were transported more than 4 cm(ring 4)within 10 days(at the end of the experiment).The current study also revealed that EBC was easily attached to the setae,cuticle,and legs of termites,implying that it could potentially be transported over a greater distance.Furthermore,transportation of EBC over larger distances indicated a potential preference of termite species between the EBC and BC particles.During the study,however,the preference among the termite species was also observed.Under the prevailing study conditions,the Coptotermes heimi and Heteroterme indicola species transported the EBC further than Microtermes obesi and Odontotermes obesus.These findings revealed that transportation preferences were observed among the four termite species.In conclusion,the current study found that termites were involved in the distribution of BC particles,with a preference for EBC and that these have the potential to transport BC particles more than 4 cm within 10 days.Furthermore,two species Coptotermes heimi and Heteroterme indicola may be more suitable candidates for EBC transpiration in Pakistani soils.It was necessary to conduct additional research into the effect of temperature on the transportation process.
文摘Super Absorbent Polyacrylate (SAP) hydrogels absorb and store water thereby aiding plant establishment when incurporated in the soil. The effect of cross-linked SAP hydrogel amendment on the performance of tree seedlings of Picea abies, Pinus sylivestris and Fagus sylvatica grown in temperate soils under water stress and non-water stress periods was investigated in a green house. The objective was to compare the root and shoot biomass of seedlings of the three species grown in sand, loam and clay soils amended with 0.4% w/w hydrogel in non water stress conditions as well as survival, root and shoot biomass after subjection to water stress. The seedlings were grown for 16 weeks, harvested and shoot as well as root biomass determined before water stress. The seedlings were also subjected to water stress and their biomass assessed at death following the water stress. The results showed that root and shoot biomass were generally higher in hydrogel amended soils compared to the controls. Root and shoot biomass of Fagus sylvatica was lower compared to Picea abies and Pinus sylivestris before water stress. The 0.4% hydrogel amendment significantly increased species’ survival in the different soils studied. Although root biomass was higher in hydrogel amended sandy soil compared to other soils, P. sylivestris and F. sylvatica shoot biomass were higher in hydrogel amended clay and loam soils compared to the sandy soil after water stress. Biomass was higher in sand compared to loam and clay soils under non-water and water stressed conditions. Since SAP hydrogel amendment improved the survival and biomass production of tree seedlings before and after water stress, use of SAPs could be promoted to enhance seedling production in water stress and non-water stress environments.
基金supported by National Natural Science Foundation of China(31971865)to LF.
文摘Weeds cause tremendous economic and ecological damage worldwide.The number of genomes established for weed species has sharply increased during the recent decade,with some 26 weed species having been sequenced and de novo genomes assembled.These genomes range from 270 Mb(Barbarea vulgaris)to almost 4.4 Gb(Aegilops tauschii).Importantly,chromosome-level assemblies are now available for 17 of these 26 species,and genomic investigations on weed populations have been conducted in at least 12 species.The resulting genomic data have greatly facilitated studies of weed management and biology,especially origin and evolution.Available weed genomes have indeed revealed valuable weed-derived genetic materials for crop improvement.In this review,we summarize the recent progress made in weed genomics and provide a perspective for further exploitation in this emerging field.
基金the National Key R&D Programe of China (grant no. 2017YFD0300100)Shanghai Agriculture Applied Technology Development Program, China (grant no. G2016060107)+4 种基金Shanghai Natural Science Foundation (17ZR1425500)National High-Tech Research and Development Program of China (863 Plan (grant no.2014AA10A603)Shan ghai Agriculture Applied Tech no logy Developme nt Program, China (grant no. 2017-02-08-00-08-F00071)National Natural Science Foundation of China (grant no. 31501270)Shared Platform of Crop Germplasm Resources in Shanghai (18DZ2293700).
文摘Drought resistance is required in rice breeding to address the challenge of frequent droughts . However, the evolutionary mechanism of rice drought resistance is not fully understood. We investigated the genetic differentiation between upland and lowland rice domesticated in agro-ecosystems with contrasting water-soil conditions using genome-wide SNPs. We estimated morphological differences among upland and lowland rice in drought resistance and productivity through common garden experiments. Upland rice had better drought resistance but poorer productivity. The negative correlations between traits of drought resistance and productivity are attributed to the underlying genetic trade-offs through tight linkages (e.g., DCA1 and OsCesA7) or pleiotropic effects (e.g., LAX1). The genetic trade-offs are comm on and greatly shape the evolutio n of drought resista nee in upland rice . In genomic regions associated with both productivity and drought resistance, signs of balancing selection were detected in upland rice, while signs of directional selection were detected in lowland rice, potentially contributing to their adaptive differentiation. Signs of balancing selection in upland rice resulted from bi-directional selection during its domestication in drought-prone upland agro-ecosystems.Using genome-wide association analysis, we ide ntified several valuable quantitative trait loci associated with drought resista nee, for which highly differentiated genes should be considered candidates. Bi-directional selection breaking tight linkages by accumulating recombination events would be applicable in breeding water-saving and droughtresistance rice.
基金We are grateful to Da-Wen Li and Ailaoshan Station for Subtropical Forest Ecosystem Studies, Chinese Academy of Sciences for field assistance. This work was supported by the National Natural Science Foundation of China （31100410, 31470575 and 30830027）, the National Key Technology R＆D Program of China （2011BAD30B00）, and Chinese Academy Science 135 Program （XTBG-T01, F01）.
文摘Soil microbes are one of the most important determinants of allelopathic effects in the field. However, most studies testing the role of allelopathy in biological invasions did not consider the roles of soil microbes. Here we tested the hypothesis that soil microbes which can degrade allelochemicals may accumulate in soils over time by adaptation and therefore increase the degradation of allelochemicals and alleviate the allelopathic effects in biological invasions. As expected, soil microbes signifi- cantly decreased the allelopathic effects of leaf leachates of eight in the nine invasive plant species studied. In addition, Ageratina adenophora showed lower allelopathic effects in soil with long or intermediately invasion history than those in soil with short invasion history. The two main allelo- chemicals of the invader were degraded more rapidly with increasing invasion history in the soil. Correspondingly,biomass and activity of the soil microbes were higher in the soils with long invasion history than in that with short invasion history. Our results indicate that soil microbes may graduaUy adapt to the allelochemicals of Ageratina and alleviate its allelopathic effects and thus support the above hypothesis. It is necessary to consider the effects of soil microbes when testing the roles of allelopathy or the novel weapons hypothesis in biological invasions.
基金funded by the German Research Foundation (DFG) — 328017493/GRK 2366 (International Research Training Group “Adaptation of maize-based food-feed-energy systems to limited phosphate resources”)
文摘Phosphorus(P)is essential for life and for efficient crop production,but global P use with limited recycling is inefficient in several sectors,including agronomy.Unfortunately,plant physiologists,agronomists,farmers and end users employ different measures for P use efficiency(PUE),which often masks their values at different scales.The term P use effectiveness,which also considers energetic and sustainability measures in addition to P balances,is also a valuable concept.Major physiological and genetic factors for plant P uptake and utilization have been identified,but there has been limited success in genetically improving PUE of modern crop cultivars.In maize,studies on root architectural and morphological traits appear promising.Rhizosphere processes assist in mobilizing and capturing sparingly soluble phosphate from rock phosphate.Combinations of phosphate-solubilizing microorganisms with ammonium-based nitrogen fertilizer,as well as strategies of fertilizer placement near the roots of target crops,can moderately enhance PUE.The desired concentration of P in the products differs,depending on the final use of the crop products as feed,food or for energy conversion,which should be considered during crop production.
基金supported by the China Postdoctoral Science Foundation(2019M662066)the National Postdoctoral Program for Innovative Talents(BX20200301)+1 种基金the National Natural Science Foundation of China(91740108)the Jiangsu Collaborative Innovation Center for Modern Crop.
文摘Dear Editor,Many functional characteristics of plant tissue attribute to highly specialized cells in the tissue.Dissecting cell types and profiling the transcriptome and proteome of individual cell types of plant tissues are important for understanding cellular activities underlying plant development and stress adaptation(Shaw et al.,2021).Single-cell RNA sequencing(scRNA-seq)provides such a tool for studying the transcriptional activities of individual cell types at single-cell resolution in any given organism(Rich-Griffin et al.,2020).
