Pythium stalk rot(PSR)is a destructive disease of maize,severely affecting yield and grain quality.The identification of quantitative trait loci(QTL)or genes for resistance to PSR forms the basis of diseaseresistant h...Pythium stalk rot(PSR)is a destructive disease of maize,severely affecting yield and grain quality.The identification of quantitative trait loci(QTL)or genes for resistance to PSR forms the basis of diseaseresistant hybrids breeding.In this study,a major QTL,Resistance to Pythium stalk rot 1(RPSR1),was identified from a set of recombinant inbred lines derived from MS71 and POP.Using a recombinant progeny testing strategy,RPSR1 was fine-mapped in a 472 kb interval.Through candidate gene expression,gene knock-down and knock-out studies,a leucine-rich repeat receptor-like kinase gene,PEP RECEPTOR 2(ZmPEPR2),was assigned as a PSR resistance gene.These results provide insights into the genetic architecture of resistance to PSR in maize,which should facilitate breeding maize for resistance to stalk rot.展开更多
High-density planting increases maize yield but also canopy crowding and stalk lodging.Aiming this contradiction,a wavy canopy was created using interlaced chemical application(IC)of a plant growth retardant at the V1...High-density planting increases maize yield but also canopy crowding and stalk lodging.Aiming this contradiction,a wavy canopy was created using interlaced chemical application(IC)of a plant growth retardant at the V14 stage with three densities(60,000,75,000,and 90,000 plants ha-1,indicated by D1,D2,and D3,respectively)for two seasons.The results showed that the IC-treated wavy canopy featuring both natural height(IC-H)and dwarfed(IC-L)plants,improved light transmission by 8.54%,8.49%,and 16.49%on average than the corresponding controls(CK)at D1,D2,and D3,respectively.The alleviation of canopy crowding stimulated leaf photosynthesis,sugar availability,basal-internode strength,and decreased plant lodging ratios in both IC-H and IC-L,particularly under higher densities.Meanwhile,the IC populations produced significantly higher yield than CK,with an average increase of 3.38%,16.70%,and 15.28%at D1,D2,and D3,respectively.Collectively,this study proposed a new wavy canopy strategy using plant growth retardant to simultaneously increase yield performance and lodging resistance,thus offering a sustainable solution for further development of high-density maize production.展开更多
Chromosomal DNA double-strand breaks(DSBs)are often generated in the genome of all living organisms.To combat DNA damage,organisms have evolved several DSB repair mechanisms,with nonhomologous end-joining(NHEJ)and hom...Chromosomal DNA double-strand breaks(DSBs)are often generated in the genome of all living organisms.To combat DNA damage,organisms have evolved several DSB repair mechanisms,with nonhomologous end-joining(NHEJ)and homologous recombination(HR)being the two most prominent.Although two major pathways have been extensively studied in Arabidopsis,rice and other mammals,the exact functions and differences between the two DSB repair pathways in maize still remain less well understood.Here,we characterized mre11a and rad50,mutants of HR pathway patterns,which showed drastic degradation of the typically persistent embryo and endosperm during kernel development.Loss of MRE11 or RAD50 function led to chromosomal fragments and chromosomal bridges in anaphase.While we also reported that the NHEJ pathway patterns,KU70 and KU80 are associated with developmental growth and genome stability.ku70 and ku80 both displayed an obvious dwarf phenotype.Cytological analysis of the mutants revealed extensive chromosome fragmentation in metaphase and subsequent stages.Loss of KU70/80 function upregulated the expression of genes involved in cell cycle progression and nuclear division.These results provide insights into how NHEJ and HR are mechanistically executed during different plant developmental periods and highlight a competitive and complementary relationship between the NHEJ and HR pathways for DNA double-strand break repair in maize.展开更多
Maize(Zea mays)is the most widely cultivated crop in the world.Maize production is closely linked to the extensive uptake and utilization of various mineral nutrients.Potassium(K),calcium(Ca),and magnesium(Mg)are esse...Maize(Zea mays)is the most widely cultivated crop in the world.Maize production is closely linked to the extensive uptake and utilization of various mineral nutrients.Potassium(K),calcium(Ca),and magnesium(Mg)are essential metallic macronutrients for plant growth and development.Sodium(Na)is an essential micronutrient for some C4 and CAM plants.Several metallic micronutrients like iron(Fe),manganese(Mn),and zinc(Zn)serve as enzyme components or co-factors in plant cells.Maize has to face the combined ion stress conditions in the natural environment.The limited availability of these nutrients in soils restricts maize production.In saline land,excessive Na could inhibit the uptake of mineral elements.Additionally,aluminum(Al)and heavy metals cadmium(Cd)and lead(Pb)in soils are toxic to maize and pose a threat to food security.Thus,plants must evolve complex mechanisms to increase nutrient uptake and utilization while restraining harmful elements.This review summarizes the research progress on the uptake and transport of metal ions in maize,highlights the regulation mechanism of metal ion transporters under stress conditions,and discusses the future challenges for the improvement of maize with high nutrient utilization efficiency(NUE).展开更多
Maize serves as a crucial cereal crop globally,yet the escalating frequency of drought stress during the reproductive phase poses a significant threat to grain yield by causing an irreversible loss in kernel number.En...Maize serves as a crucial cereal crop globally,yet the escalating frequency of drought stress during the reproductive phase poses a significant threat to grain yield by causing an irreversible loss in kernel number.Enhancing reproductive drought tolerance in maize requires elucidating the physiological mechanisms underlying its response to drought stress,which can then be incorporated into the development of new maize varieties through breeding programs.Additionally,innovative cultivation practices must be devised to complement these genetic improvements.In this review,the timing,duration,and severity of drought stress during the reproductive stage and their effects on maize kernel set are assessed,providing a basis for constructing a framework that links kernel setting to drought stress.Based on this framework,reproductive drought tolerance from tasseling through post-fertilization kernel establishment is subsequently examined.Evidence indicates that drought-induced fertilization failure is primarily due to delayed pollination resulting from slower silk elongation,which is caused by the loss of cell turgor and reduced carbon supply.Meanwhile,kernel abortion after fertilization is mainly triggered by carbohydrate starvation,increased ethylene emission,and the accumulation of abscisic acid(ABA).Therefore,sugar metabolism,hydraulic status,and hormone signaling collectively regulate maize's kernel setting tolerance to drought stress in a synergistic manner.Several novel gene candidates with potential for conferring drought tolerance in maize have been identified,offering promising targets for genetic improvement through genome editing combined with targeted cultivation practices to enhance maize drought tolerance and ensure stable grain yield in future crops.展开更多
Maize(Zea mays L.)is a globally significant crop essential for food,feed,and bioenergy production.The maize kernel,serving as a primary sink for starch,proteins,lipids,and essential micronutrients,is crucial for enhan...Maize(Zea mays L.)is a globally significant crop essential for food,feed,and bioenergy production.The maize kernel,serving as a primary sink for starch,proteins,lipids,and essential micronutrients,is crucial for enhancing maize yield and quality.Previous studies have established the critical role of Polycomb Repressive Complex 2(PRC2)in regulating kernel development.In this study,we applied a reverse genetics approach to investigate the role of ZmFIE1,the homolog of the PRC2 complex component Extra sex combs(Esc),in maize development.The functional loss of ZmFIE1 significantly reduces embryo size in the early stage but has a relatively small impact on mature kernels.Integrating transcriptional and metabolomic profiling suggests that ZmFIE1 is involved in regulating nutrient balance between the endosperm and embryo.In addition,we demonstrate that ZmFIE1 is maternally expressed,and that the maternal inheritance of the fie1 allele significantly affects the imprinting status of paternally imprinted genes.Overall,our results suggest that ZmFIE1 is a key gene involved in the modulation of embryo development via regulating genomic imprinting and nutrient balance between embryo and endosperm,which provides new insights into the regulation mechanism underlying kernel development.展开更多
Transcription factors play critical roles in the regulation of gene expression during maize kernel development.The maize endosperm,a large storage organ,accounting for nearly 90%of the dry weight of mature kernels,ser...Transcription factors play critical roles in the regulation of gene expression during maize kernel development.The maize endosperm,a large storage organ,accounting for nearly 90%of the dry weight of mature kernels,serves as the primary site for starch storage.In this study,we identify an endosperm-specific EREB gene,ZmEREB167,which encodes a nucleus-localized EREB protein.Knockout of ZmEREB167 significantly increases kernel size and weight,as well as starch and protein content,compared with the wild type.In situ hybridization experiments show that ZmEREB167 is highly expressed in the BETL as well as PED regions of maize kernels.Dual-luciferase assays show that ZmEREB167 exhibits transcriptionally repressor activity in maize protoplasts.Transcriptome analysis reveals that a large number of genes are up-regulated in the Zmereb167-C1 mutant compared with the wild type,including key genetic factors such as ZmMRP-1 and ZmMN1,as well as multiple transporters involved in maize endosperm development.Integration of RNA-seq and ChIP-seq results identify 68 target genes modulated by ZmEREB167.We find that ZmEREB167 directly targets OPAQUE2,ZmNRT1.1,ZmIAA12,ZmIAA19,and ZmbZIP20,repressing their expressions.Our study demonstrates that ZmEREB167 functions as a negative regulator in maize endosperm development and affects starch accumulation and kernel size.展开更多
Meiosis,a critical process for sexual reproduction,requires precise regulation to ensure the correct progression of meiotic stages.In yeast and animals,errors in meiotic recombination and homologous chromosomes synaps...Meiosis,a critical process for sexual reproduction,requires precise regulation to ensure the correct progression of meiotic stages.In yeast and animals,errors in meiotic recombination and homologous chromosomes synapsis bring a surveillance mechanism named pachytene checkpoint to prevent pachytene exit.However,most plant mutants with defects in meiotic prophase I continue cell cycle progression,which hindered the characterization of factors controlling the prophase I to metaphase I transition.Here,we characterized a male-sterile mutant in maize,prolonged prophase1(pp1),which exhibited pachytene and diakinesis arrest in male meiosis,and abnormal chromatin condensation.Using mapbased cloning,the PP1 gene was isolated as a PHD family transcription factor,and its transcripts of PP1 were preferentially accumulated in tapetum and male germline cells during microsporogenesis.Transcriptomic analysis of the pp1 mutant revealed downregulation of genes associated with chromatin assembly,cell cycle,and male meiosis,correlating with observed meiotic arrest and chromatin condensation defects.These findings highlight the role of PP1 in maize microsporogenesis,and providing more insights into the mechanisms regulating the meiotic progression in maize.展开更多
Anther is a key male reproductive organ that is essential for the plant life cycle,from the sporophyte to the gametophyte generation.To explore the isoform-level transcriptional landscape of developing anthers in maiz...Anther is a key male reproductive organ that is essential for the plant life cycle,from the sporophyte to the gametophyte generation.To explore the isoform-level transcriptional landscape of developing anthers in maize(Zea mays L.),we analyzed Iso-Seq data from anthers collected at 10 developmental stages,together with strand-specific RNA-seq,CAGE-seq,and PAS-seq data.Of the 152,026 high-confidence full-length isoforms identified,68.8%have not been described;these include 22,365 isoforms that originate from previously unannotated loci and 82,167 novel isoforms that originate from annotated protein-coding genes.Using our newly developed strategy to detect dynamic expression patterns of isoforms,we identify 13,899 differentially variable regions(DVRs);surprisingly,1275 genes contain more than two DVRs,revealing highly efficient utilization of limited genic regions.We identify 7876 long non-coding RNAs(IncRNAs)from 4098 loci,most of which were preferentially expressed during cell differentiation and meiosis.We also detected 371 long-range interactions involving intergenic IncRNAs(lincRNAs);interestingly,243 were lincRNA-gene ones,and the interacting genes were highly expressed in anthers,suggesting that many potential IncRNA regulators of key genes are required for anther development.This study provides valuable resources and fundamental information for studying the essential transcripts of key genes during anther development.展开更多
Dear Editor,Multi-omics association analysis is a key method in crop germplasm research,helping to elucidate the regulatory mechanisms of agronomic traits(Liu et al.,2020;Liang et al.,2021).However,most existing multi...Dear Editor,Multi-omics association analysis is a key method in crop germplasm research,helping to elucidate the regulatory mechanisms of agronomic traits(Liu et al.,2020;Liang et al.,2021).However,most existing multi-omics association studies focus on omics data under a single condition,posing challenges in identifying stress-related agronomically important genes.This difficultymainly arises fromthe increased complexity ofmulti-omics analyseswhen comparing control and stress conditions.展开更多
Understanding gene regulatory networks(GRNs)is essential for improving maize yield and quality through molecular breeding approaches.The lack of comprehensive transcription factor(TF)-DNA interaction data has hindered...Understanding gene regulatory networks(GRNs)is essential for improving maize yield and quality through molecular breeding approaches.The lack of comprehensive transcription factor(TF)-DNA interaction data has hindered accurate GRN predictions,limiting our insight into the regulatory mechanisms.In this study,we performed large-scale profiling of maize TF binding sites.We obtained and collected reliable binding profiles for 513 TFs,identified 394,136 binding sites,and constructed an accuracy-enhanced maize GRN(mGRN+)by integrating chromatin accessibility and gene expression data.The mGRN+comprises 397,699 regulatory relationships.We further divided the mGRN+into multiple modules across six major tis-sues.Using machine-learning algorithms,we optimized the mGRN+to improve the prediction accuracy of gene functions and key regulators.Through independent genetic validation experiments,we further confirmed the reliability of these predictions.This work provides the largest collection of experimental TF binding sites in maize and highly optimized regulatory networks,which serve as valuable resources forstudyingmaize genefunctionand crop improvement.展开更多
During the early systemic infection of plant pathogens,individual cells can harbor pathogens at various stages of infection,ranging from absent to abundant.Consequently,gene expression levels within these cells in res...During the early systemic infection of plant pathogens,individual cells can harbor pathogens at various stages of infection,ranging from absent to abundant.Consequently,gene expression levels within these cells in response to the pathogens exhibit significant variability.These variations are pivotal in determining pathogenicity or susceptibility,yet they remain largely unexplored and poorly understood.Sugarcane mosaic virus(SCMV)is a representative member of the monocot-infecting potyviruses with a polyadeny-lated RNA genome,which can be captured by single-cell RNA sequencing(scRNA-seq).Here,we per-formed scRNA-seq on SCMV-infected maize leaves during early systemic infection(prior to symptom mani-festation)to investigate the co-variation patterns between viral accumulation and intracellular gene expression alterations.We identifiedfive cell types and found that mesophyll-4(MS4)cells exhibited the highest levels of viral accumulation in most cells.Early systemic infection of SCMV resulted in a greater up-regulation of differentially expressed genes,which were mainly enriched in biological processes related to translation,peptide biosynthesis,and metabolism.Co-variation analysis of the altered maize gene expres-sion and viral accumulation levels in MS1,2,and 4 revealed several patterns,and the co-expression rela-tionships between them were mainly positive.Furthermore,functional studies identified several potential anti-or pro-viral factors that may play crucial roles during the early stage of SCMV systemic infection.These results not only provide new insights into plant gene regulation during viral infection but also offer a foundation for future investigations of host–virus interactions across molecular,cellular,and physiolog-ical scales.展开更多
Diversifying crop rotation aims to balance production and ecological concerns.However,yield and water use efficiency(WUE)of crop in diversified rotation systems have not been well documented,especially under limited i...Diversifying crop rotation aims to balance production and ecological concerns.However,yield and water use efficiency(WUE)of crop in diversified rotation systems have not been well documented,especially under limited irrigation.Here,we conducted a 6-year experiment with five treatments:1)wheatmaize cropping system(WM),as control;2)WMME,spring maize→WM rotation;3)WMML,spring millet→WM rotation;4)WMMP,spring peanut→WM rotation;and 5)WMMS,spring soybean→WM rotation,to explore how diversified rotations affected yield and WUE of wheat.Results showed that approximately 60% higher precipitation during wheat growing season in Cycle 1(2015-2017)resulted in yield increases by 33.8%-55.7% compared to those in Cycle 2(2017-2019)and Cycle3(2019-2021).Grain yield and WUE of wheat were 16.7% and 9.6% higher in Cycle 1,81.5% and 86.8% higher in Cycle 2,and 56.1% and 78.7% higher in Cycle 3 on average in diversified rotations compared to those in WM,respectively.Further analysis revealed that spike number and aboveground biomass were the main contributors to the increments,which can be explained by the increased evapotranspiration during the middle-late wheat growth stages(e.g.,regreening,jointing,and anthesis)in diversified rotations.In general,diversified rotations enhanced synchronization of soil water supply with crop water demand by affecting the spatiotemporal dynamics of soil moisture under varied precipitation conditions,thereby increasing yield and WUE of wheat.Hence,diversified spring crops→WM rotations offer a sustainable and efficient strategy for enhancing wheat production and water conservation in dry areas.展开更多
Understanding the role of heterotic genes in contributing to heterosis is essential for advancing hybrid breeding.We analyzed plant height(PH),ear height(EH),and transcriptomic data from a maize hybrid pop-ulation.Gen...Understanding the role of heterotic genes in contributing to heterosis is essential for advancing hybrid breeding.We analyzed plant height(PH),ear height(EH),and transcriptomic data from a maize hybrid pop-ulation.Genome-wide association studies(GWASs)revealed that dominance effects of quantitative trait loci(QTLs)play a significant role in hybrid traits and mid-parent heterosis.By integrating GWAS,expression GWAS(eGWAS),and module eGWAS analysis,we prioritized six candidate heterotic genes underlying six QTLs,including one QTL that spans the bZIP29 gene.In the hybrid population,bZIP29 exhibits additive expression and dominance effects for both hybrid traits and mid-parent heterosis,with its favorable allele correlating positively with PH and EH.bZIP29 demonstrates dominance or over-dominance patterns in hy-brids derived from crosses between transgenic and wild-type lines,contingent upon its expression.A tsCUT&Tag assay revealed that bZIP29 protein binds directly to a gene regulated by its associated expres-sion QTL(eQTL)and six genes within expression modules governed by its associated module-eQTLs(meQTLs).Regulatory networks involving bZIP29 are more extensive in hybrid subpopulations than in the parental population.This study offers insights into key heterotic genes and networks that underpin the robust growth of hybrid maize.展开更多
Maize(Zea mays L.)is not only an important cereal crop,but also a model plant species for genetic,cytologic,genomic,and molecular studies.Maize possesses tremendous phenotypic and genetic diversity.During the past few...Maize(Zea mays L.)is not only an important cereal crop,but also a model plant species for genetic,cytologic,genomic,and molecular studies.Maize possesses tremendous phenotypic and genetic diversity.During the past few decades,researchers have made significant advances in multiple areas,including the genomic compositions and variations of maize and its ancestors,the genetic and genomic bases of maize domestication and evolution,the genetic architecture of various agronomic traits(yield,quality,biotic and abiotic stress responses,nutrient use efficiency,fertility and heterosis),and the development of novel molecular breeding technologies.In this review,we summarize these research achievements and provide a perspective for future maize research and breeding.展开更多
Maize(Zea mays)is one of the most important crops in the world,but its yield and quality are seriously affected by diverse diseases.Identifying broad-spectrum resistance genes is crucial for developing effective strat...Maize(Zea mays)is one of the most important crops in the world,but its yield and quality are seriously affected by diverse diseases.Identifying broad-spectrum resistance genes is crucial for developing effective strategies to control the disease in maize.In a genome-wide study in maize,we identified a G-type lectin receptor kinase ZmLecRK1,as a new resistance protein against Pythium aphanidermatum,one of the causal pathogens of stalk rot in maize.Genetic analysis showed that the specific ZmLecRK1 allele can confer resistance to multiple pathogens in maize.The cell death and disease resistance phenotype mediated by the resistant variant of ZmLecRK1 requires the co-receptor ZmBAK1.A naturally occurring A404S variant in the extracellular domain of ZmLecRK1 determines the ZmLecRK1-ZmBAK1 interaction and the formation of ZmLecRK1-related protein complexes.Interestingly,the ZmLecRK1 susceptible variant was found to possess the amino acid S404 that is present in the ancestral variants of ZmLecRK1 and conserved among the majority of grass species,while the resistance variant of ZmLecRK1 with A404 is only present in a few maize inbred lines.Substitution of S by A at position 404 in ZmLecRK1-like proteins of sorghum and rice greatly enhances their ability to induce cell death.Further transcriptomic analysis reveals that ZmLecRK1 likely regulates gene expression related to the pathways in cell wall organization or biogenesis in response to pathogen infection.Taken together,these results suggest that the ZmLecRK1 resistance variant enhances its binding affinity to the co-receptor ZmBAK1,thereby enhancing the formation of active complexes for defense in maize.Our work highlights the biotechnological potential for generating disease-resistant crops by precisely modulating the activity of ZmLecRK1 and its homologs through targeted base editing.展开更多
Understanding how maize(Zea mays)responds to cold stress is crucial for facilitating breeding programs of cold-tolerant varieties.Despite extensive utilization of the genome-wide association study(GWAs)approach for ex...Understanding how maize(Zea mays)responds to cold stress is crucial for facilitating breeding programs of cold-tolerant varieties.Despite extensive utilization of the genome-wide association study(GWAs)approach for exploring favorable natural alleles associated with maize cold tolerance,few studies have successfully identified candidate genes that contribute to maize cold tolerance.In this study,we used a diverse panel of inbred maize lines collected from different germplasm sources to perform a GWAS on var-iations in the relative injured area of maize true leaves during cold stress-a trait very closely correlated with maize cold tolerance.We identified HsF21,which encodes a B-class heat shock transcription factor(HSF)that positively regulates cold tolerance at both the seedling and germination stages.Natural varia-tions in the promoter of the cold-tolerant HSF21Hap1 allele led to increased HSF21 expression under cold stress by inhibiting binding of the basic leucine zipper bziP68 transcription factor,a negative regulator of cold tolerance.By integrating transcriptome deep sequencing,DNA affinity purification sequencing,and targeted lipidomic analysis,we revealed the function of HsF21 in regulating lipid metabolism homeo-stasis to modulate cold tolerance in maize.In addition,we found that HsF21 confers maize cold tolerance without incurring yield penalties.Collectively,this study establishes HsF21 as a key regulator that en-hances cold tolerance in maize,providing valuable genetic resources for breeding of cold-tolerant maize varieties.展开更多
Maize(Zea mays)cultivation is strongly affected by both abiotic and biotic stress,leading to reduced growth and productivity.It has recently become clear that regulators of plant stress responses,including the phytoho...Maize(Zea mays)cultivation is strongly affected by both abiotic and biotic stress,leading to reduced growth and productivity.It has recently become clear that regulators of plant stress responses,including the phytohormones abscisic acid(ABA),ethylene(ET),and jasmonic acid(JA),together with reactive oxygen species(ROS),shape plant growth and development.Beyond their well established functions in stress responses,these molecules play crucial roles in balancing growth and defense,which must be finely tuned to achieve high yields in crops while maintaining some level of defense.In this review,we provide an in-depth analysis of recent research on the developmental functions of stress regulators,focusing specifically on maize.By unraveling the contributions of these regulators to maize development,we present new avenues for enhancing maize cultivation and growth while highlighting the potential risks associated with manipulating stress regulators to enhance grain yields in the face of environmental challenges.展开更多
The seed storage materials accumulate during seed development,and are essential for seed germination and seedling establishment.Here we employed two bi-parental populations of an F2:3 population developed from a cross...The seed storage materials accumulate during seed development,and are essential for seed germination and seedling establishment.Here we employed two bi-parental populations of an F2:3 population developed from a cross of improved 220(I220,small seeds with low starch)and PH4CV(large seeds with high starch),as well as recombinant-inbred lines(RILs)of X178(high starch)and its improved introgression line I178(low starch),to identify the genes that control seed storage materials.We identified a total of 12 QTLs for starch,protein and oil,which explained 3.44-10.79%of the phenotypic variances.Among them,qSTA2-1 identified in F2:3 and qSTA2-2 identified in the RILs partially overlapped at an interval of 7.314-9.554 Mb,and they explained 3.44-10.21%of the starch content variation,so they were selected for further study.Fine mapping of qSTA2-2 with the backcrossed populations of ^(I220)/PH4CV in each generation narrowed it down to a 199.7 kb interval that contains 14 open reading frames(ORFs).Transcriptomic analysis of developing seeds from the near-isogenic lines(NILs)of ^(I220)/PH4CV(BC_(5)F_(2))showed that only 11 ORFs were expressed in 20 days after pollination(DAP)seeds.Five of them were upregulated and six of them were downregulated in NIL^(I220),and the differentially expressed genes(DEGs)between NIL^(I220) and NIL^(PH4CV) were enriched in starch metabolism,hormone signal transduction and glycosaminoglycan degradation.Of the eleven NIL^(I220) differential expressed ORFs,ORF4(Zm00001d002260)and ORF5(Zm00001d002261)carry 75%protein sequence similarity,both encodes an glycolate oxidase,were the possible candidates of qSTA2-2.Further analysis and validation indicated that mutation of the qSTA2-2 locus resulted in the dysfunction of ABA accumulation,the embryo/endosperm ratio and the starch and hormone levels.展开更多
基金supported by National Natural Science Foundation of China(32302371 to Junbin Chen)the National Key Research and Development Program,Ministry of Science and Technology of China(2022YFD1201802 to Wangsheng Zhu)Research Program from State Key Laboratory of Maize Biobreeding(SKLMB2424 to Wangsheng Zhu).
文摘Pythium stalk rot(PSR)is a destructive disease of maize,severely affecting yield and grain quality.The identification of quantitative trait loci(QTL)or genes for resistance to PSR forms the basis of diseaseresistant hybrids breeding.In this study,a major QTL,Resistance to Pythium stalk rot 1(RPSR1),was identified from a set of recombinant inbred lines derived from MS71 and POP.Using a recombinant progeny testing strategy,RPSR1 was fine-mapped in a 472 kb interval.Through candidate gene expression,gene knock-down and knock-out studies,a leucine-rich repeat receptor-like kinase gene,PEP RECEPTOR 2(ZmPEPR2),was assigned as a PSR resistance gene.These results provide insights into the genetic architecture of resistance to PSR in maize,which should facilitate breeding maize for resistance to stalk rot.
基金supported by the National Key Research and Development Program of China(2023YFD2303302,2022YFD2300803)the National Natural Science Foundation of China(32160445)the China Agriculture Research System of MOF and MARA(CARS-02-16).
文摘High-density planting increases maize yield but also canopy crowding and stalk lodging.Aiming this contradiction,a wavy canopy was created using interlaced chemical application(IC)of a plant growth retardant at the V14 stage with three densities(60,000,75,000,and 90,000 plants ha-1,indicated by D1,D2,and D3,respectively)for two seasons.The results showed that the IC-treated wavy canopy featuring both natural height(IC-H)and dwarfed(IC-L)plants,improved light transmission by 8.54%,8.49%,and 16.49%on average than the corresponding controls(CK)at D1,D2,and D3,respectively.The alleviation of canopy crowding stimulated leaf photosynthesis,sugar availability,basal-internode strength,and decreased plant lodging ratios in both IC-H and IC-L,particularly under higher densities.Meanwhile,the IC populations produced significantly higher yield than CK,with an average increase of 3.38%,16.70%,and 15.28%at D1,D2,and D3,respectively.Collectively,this study proposed a new wavy canopy strategy using plant growth retardant to simultaneously increase yield performance and lodging resistance,thus offering a sustainable solution for further development of high-density maize production.
基金supported by the National Natural Science Foundation of China(32372116)to Yan He.
文摘Chromosomal DNA double-strand breaks(DSBs)are often generated in the genome of all living organisms.To combat DNA damage,organisms have evolved several DSB repair mechanisms,with nonhomologous end-joining(NHEJ)and homologous recombination(HR)being the two most prominent.Although two major pathways have been extensively studied in Arabidopsis,rice and other mammals,the exact functions and differences between the two DSB repair pathways in maize still remain less well understood.Here,we characterized mre11a and rad50,mutants of HR pathway patterns,which showed drastic degradation of the typically persistent embryo and endosperm during kernel development.Loss of MRE11 or RAD50 function led to chromosomal fragments and chromosomal bridges in anaphase.While we also reported that the NHEJ pathway patterns,KU70 and KU80 are associated with developmental growth and genome stability.ku70 and ku80 both displayed an obvious dwarf phenotype.Cytological analysis of the mutants revealed extensive chromosome fragmentation in metaphase and subsequent stages.Loss of KU70/80 function upregulated the expression of genes involved in cell cycle progression and nuclear division.These results provide insights into how NHEJ and HR are mechanistically executed during different plant developmental periods and highlight a competitive and complementary relationship between the NHEJ and HR pathways for DNA double-strand break repair in maize.
基金supported by grants from the Biological Breeding-National Science and Technology Major Project(2023ZD04072)the National Natural Science Foundation of China(32302660,32025004,and 31921001).
文摘Maize(Zea mays)is the most widely cultivated crop in the world.Maize production is closely linked to the extensive uptake and utilization of various mineral nutrients.Potassium(K),calcium(Ca),and magnesium(Mg)are essential metallic macronutrients for plant growth and development.Sodium(Na)is an essential micronutrient for some C4 and CAM plants.Several metallic micronutrients like iron(Fe),manganese(Mn),and zinc(Zn)serve as enzyme components or co-factors in plant cells.Maize has to face the combined ion stress conditions in the natural environment.The limited availability of these nutrients in soils restricts maize production.In saline land,excessive Na could inhibit the uptake of mineral elements.Additionally,aluminum(Al)and heavy metals cadmium(Cd)and lead(Pb)in soils are toxic to maize and pose a threat to food security.Thus,plants must evolve complex mechanisms to increase nutrient uptake and utilization while restraining harmful elements.This review summarizes the research progress on the uptake and transport of metal ions in maize,highlights the regulation mechanism of metal ion transporters under stress conditions,and discusses the future challenges for the improvement of maize with high nutrient utilization efficiency(NUE).
基金financially supported by the Natural Key Research and Development Program of China(2023YFD2301500)。
文摘Maize serves as a crucial cereal crop globally,yet the escalating frequency of drought stress during the reproductive phase poses a significant threat to grain yield by causing an irreversible loss in kernel number.Enhancing reproductive drought tolerance in maize requires elucidating the physiological mechanisms underlying its response to drought stress,which can then be incorporated into the development of new maize varieties through breeding programs.Additionally,innovative cultivation practices must be devised to complement these genetic improvements.In this review,the timing,duration,and severity of drought stress during the reproductive stage and their effects on maize kernel set are assessed,providing a basis for constructing a framework that links kernel setting to drought stress.Based on this framework,reproductive drought tolerance from tasseling through post-fertilization kernel establishment is subsequently examined.Evidence indicates that drought-induced fertilization failure is primarily due to delayed pollination resulting from slower silk elongation,which is caused by the loss of cell turgor and reduced carbon supply.Meanwhile,kernel abortion after fertilization is mainly triggered by carbohydrate starvation,increased ethylene emission,and the accumulation of abscisic acid(ABA).Therefore,sugar metabolism,hydraulic status,and hormone signaling collectively regulate maize's kernel setting tolerance to drought stress in a synergistic manner.Several novel gene candidates with potential for conferring drought tolerance in maize have been identified,offering promising targets for genetic improvement through genome editing combined with targeted cultivation practices to enhance maize drought tolerance and ensure stable grain yield in future crops.
基金supported by STI2030-Major Projects(2023ZD04069,Z231100003723004)the National Science Fund for Distinguished Young Scholars(32425041)the Chinese Universities Scientific Fund(2024TC165).
文摘Maize(Zea mays L.)is a globally significant crop essential for food,feed,and bioenergy production.The maize kernel,serving as a primary sink for starch,proteins,lipids,and essential micronutrients,is crucial for enhancing maize yield and quality.Previous studies have established the critical role of Polycomb Repressive Complex 2(PRC2)in regulating kernel development.In this study,we applied a reverse genetics approach to investigate the role of ZmFIE1,the homolog of the PRC2 complex component Extra sex combs(Esc),in maize development.The functional loss of ZmFIE1 significantly reduces embryo size in the early stage but has a relatively small impact on mature kernels.Integrating transcriptional and metabolomic profiling suggests that ZmFIE1 is involved in regulating nutrient balance between the endosperm and embryo.In addition,we demonstrate that ZmFIE1 is maternally expressed,and that the maternal inheritance of the fie1 allele significantly affects the imprinting status of paternally imprinted genes.Overall,our results suggest that ZmFIE1 is a key gene involved in the modulation of embryo development via regulating genomic imprinting and nutrient balance between embryo and endosperm,which provides new insights into the regulation mechanism underlying kernel development.
基金supported by STI 2030-Major Project(2023ZD04069)National Key Research and Development Program of China(2023YFD1202900)+3 种基金The National Science Fund for Distinguished Young Scholars(32425041)The“Breakthrough”Science and Technology Project of Tongliao(TL2024TW001)Science and Technology Demonstration Project of Shandong Province(2024SFGC0402)Pinduoduo-China Agricultural University Research Fund(PC2023A01004).
文摘Transcription factors play critical roles in the regulation of gene expression during maize kernel development.The maize endosperm,a large storage organ,accounting for nearly 90%of the dry weight of mature kernels,serves as the primary site for starch storage.In this study,we identify an endosperm-specific EREB gene,ZmEREB167,which encodes a nucleus-localized EREB protein.Knockout of ZmEREB167 significantly increases kernel size and weight,as well as starch and protein content,compared with the wild type.In situ hybridization experiments show that ZmEREB167 is highly expressed in the BETL as well as PED regions of maize kernels.Dual-luciferase assays show that ZmEREB167 exhibits transcriptionally repressor activity in maize protoplasts.Transcriptome analysis reveals that a large number of genes are up-regulated in the Zmereb167-C1 mutant compared with the wild type,including key genetic factors such as ZmMRP-1 and ZmMN1,as well as multiple transporters involved in maize endosperm development.Integration of RNA-seq and ChIP-seq results identify 68 target genes modulated by ZmEREB167.We find that ZmEREB167 directly targets OPAQUE2,ZmNRT1.1,ZmIAA12,ZmIAA19,and ZmbZIP20,repressing their expressions.Our study demonstrates that ZmEREB167 functions as a negative regulator in maize endosperm development and affects starch accumulation and kernel size.
基金supported by National Key Research and Development Program of China(2022YFF1003501)Biological BreedingMajor Projects(2023ZD04076)+1 种基金Funds from State Key Laboratory of Maize Bio-breeding(SKLMB2404,SKLMB2440)Anhui Natural Science Foundation(2308085QC92).
文摘Meiosis,a critical process for sexual reproduction,requires precise regulation to ensure the correct progression of meiotic stages.In yeast and animals,errors in meiotic recombination and homologous chromosomes synapsis bring a surveillance mechanism named pachytene checkpoint to prevent pachytene exit.However,most plant mutants with defects in meiotic prophase I continue cell cycle progression,which hindered the characterization of factors controlling the prophase I to metaphase I transition.Here,we characterized a male-sterile mutant in maize,prolonged prophase1(pp1),which exhibited pachytene and diakinesis arrest in male meiosis,and abnormal chromatin condensation.Using mapbased cloning,the PP1 gene was isolated as a PHD family transcription factor,and its transcripts of PP1 were preferentially accumulated in tapetum and male germline cells during microsporogenesis.Transcriptomic analysis of the pp1 mutant revealed downregulation of genes associated with chromatin assembly,cell cycle,and male meiosis,correlating with observed meiotic arrest and chromatin condensation defects.These findings highlight the role of PP1 in maize microsporogenesis,and providing more insights into the mechanisms regulating the meiotic progression in maize.
基金supported by the Excellent Young Scientists Fund(Category B)(32422063)the National Key Research and Development Program of China(2022YFF1003500)the Zhengzhou University Qiushi Postdoctoral Research Funding Program.For open access,the authors have applied for a Creative Commons Attribution(CC BY)license for any Author Accepted Manuscript version arising from this submission.
文摘Anther is a key male reproductive organ that is essential for the plant life cycle,from the sporophyte to the gametophyte generation.To explore the isoform-level transcriptional landscape of developing anthers in maize(Zea mays L.),we analyzed Iso-Seq data from anthers collected at 10 developmental stages,together with strand-specific RNA-seq,CAGE-seq,and PAS-seq data.Of the 152,026 high-confidence full-length isoforms identified,68.8%have not been described;these include 22,365 isoforms that originate from previously unannotated loci and 82,167 novel isoforms that originate from annotated protein-coding genes.Using our newly developed strategy to detect dynamic expression patterns of isoforms,we identify 13,899 differentially variable regions(DVRs);surprisingly,1275 genes contain more than two DVRs,revealing highly efficient utilization of limited genic regions.We identify 7876 long non-coding RNAs(IncRNAs)from 4098 loci,most of which were preferentially expressed during cell differentiation and meiosis.We also detected 371 long-range interactions involving intergenic IncRNAs(lincRNAs);interestingly,243 were lincRNA-gene ones,and the interacting genes were highly expressed in anthers,suggesting that many potential IncRNA regulators of key genes are required for anther development.This study provides valuable resources and fundamental information for studying the essential transcripts of key genes during anther development.
基金supported by the Biological Breeding-Major Projects(2023ZD04076)the Pinduoduo-China Agricultural University Research Fund(PC2023B01012)+1 种基金the 2115 Talent Development Program of China Agricultural University,the National Natural Science Foundation of China(32201718)the Science and Technology Demonstration Project of Shandong Province(2024SFGC0402).
文摘Dear Editor,Multi-omics association analysis is a key method in crop germplasm research,helping to elucidate the regulatory mechanisms of agronomic traits(Liu et al.,2020;Liang et al.,2021).However,most existing multi-omics association studies focus on omics data under a single condition,posing challenges in identifying stress-related agronomically important genes.This difficultymainly arises fromthe increased complexity ofmulti-omics analyseswhen comparing control and stress conditions.
基金supported by the Biological Breeding-Major Projects(2023ZD0403005)the National Natural Science Foundation of China(32372123,32301846)+1 种基金the National Key Research and Development Program of China(2023YFF1000400)supported by the University of Arizona College of Agriculture,Life and Environmental Sciences,and the USDA.
文摘Understanding gene regulatory networks(GRNs)is essential for improving maize yield and quality through molecular breeding approaches.The lack of comprehensive transcription factor(TF)-DNA interaction data has hindered accurate GRN predictions,limiting our insight into the regulatory mechanisms.In this study,we performed large-scale profiling of maize TF binding sites.We obtained and collected reliable binding profiles for 513 TFs,identified 394,136 binding sites,and constructed an accuracy-enhanced maize GRN(mGRN+)by integrating chromatin accessibility and gene expression data.The mGRN+comprises 397,699 regulatory relationships.We further divided the mGRN+into multiple modules across six major tis-sues.Using machine-learning algorithms,we optimized the mGRN+to improve the prediction accuracy of gene functions and key regulators.Through independent genetic validation experiments,we further confirmed the reliability of these predictions.This work provides the largest collection of experimental TF binding sites in maize and highly optimized regulatory networks,which serve as valuable resources forstudyingmaize genefunctionand crop improvement.
基金supported by grants from the National Natural Science Foundation of China(grant 32072384,W2412104)the China Agriculture Research System of MOF and MARA(CARS-02)+2 种基金This study was also supported by the Ministry of Agriculture and Rural Affairs of China(NK2023070202)S.C.G.is supported by startup funds from the University of California,Riversideby a grant from the National Institute of General Medical Sciences of the National Institutes of Health(award no.R35GM151194).
文摘During the early systemic infection of plant pathogens,individual cells can harbor pathogens at various stages of infection,ranging from absent to abundant.Consequently,gene expression levels within these cells in response to the pathogens exhibit significant variability.These variations are pivotal in determining pathogenicity or susceptibility,yet they remain largely unexplored and poorly understood.Sugarcane mosaic virus(SCMV)is a representative member of the monocot-infecting potyviruses with a polyadeny-lated RNA genome,which can be captured by single-cell RNA sequencing(scRNA-seq).Here,we per-formed scRNA-seq on SCMV-infected maize leaves during early systemic infection(prior to symptom mani-festation)to investigate the co-variation patterns between viral accumulation and intracellular gene expression alterations.We identifiedfive cell types and found that mesophyll-4(MS4)cells exhibited the highest levels of viral accumulation in most cells.Early systemic infection of SCMV resulted in a greater up-regulation of differentially expressed genes,which were mainly enriched in biological processes related to translation,peptide biosynthesis,and metabolism.Co-variation analysis of the altered maize gene expres-sion and viral accumulation levels in MS1,2,and 4 revealed several patterns,and the co-expression rela-tionships between them were mainly positive.Furthermore,functional studies identified several potential anti-or pro-viral factors that may play crucial roles during the early stage of SCMV systemic infection.These results not only provide new insights into plant gene regulation during viral infection but also offer a foundation for future investigations of host–virus interactions across molecular,cellular,and physiolog-ical scales.
基金supported by grants from the Biological Breeding-National Science and Technology Major Project(2023ZD0402701 and 2024ZD04077)the National Natural Science Foundation of China(32425041)+1 种基金the National Key Research and Development Program of China(2021YFD1200701)the Joint Research on Maize Improvement of Henan(2022010202).
文摘Dear Editor,Maize(Zea mays L.)is a globally crucial crop that exhibits serious genotype dependency,which renders its genetic transformation challenging.Agrobacterium(Agrobacterium tumefaciens)-mediated transformation depends on(1)the recipient’s susceptibility to Agrobacterium infection and(2)the ability to form embryogenic callus.
基金supported by the National Natural Science Foundation of China(32172125 and U21A20218)。
文摘Diversifying crop rotation aims to balance production and ecological concerns.However,yield and water use efficiency(WUE)of crop in diversified rotation systems have not been well documented,especially under limited irrigation.Here,we conducted a 6-year experiment with five treatments:1)wheatmaize cropping system(WM),as control;2)WMME,spring maize→WM rotation;3)WMML,spring millet→WM rotation;4)WMMP,spring peanut→WM rotation;and 5)WMMS,spring soybean→WM rotation,to explore how diversified rotations affected yield and WUE of wheat.Results showed that approximately 60% higher precipitation during wheat growing season in Cycle 1(2015-2017)resulted in yield increases by 33.8%-55.7% compared to those in Cycle 2(2017-2019)and Cycle3(2019-2021).Grain yield and WUE of wheat were 16.7% and 9.6% higher in Cycle 1,81.5% and 86.8% higher in Cycle 2,and 56.1% and 78.7% higher in Cycle 3 on average in diversified rotations compared to those in WM,respectively.Further analysis revealed that spike number and aboveground biomass were the main contributors to the increments,which can be explained by the increased evapotranspiration during the middle-late wheat growth stages(e.g.,regreening,jointing,and anthesis)in diversified rotations.In general,diversified rotations enhanced synchronization of soil water supply with crop water demand by affecting the spatiotemporal dynamics of soil moisture under varied precipitation conditions,thereby increasing yield and WUE of wheat.Hence,diversified spring crops→WM rotations offer a sustainable and efficient strategy for enhancing wheat production and water conservation in dry areas.
基金supported by the National Key R&D Program of China(2023YFF1000400)the Biological Breeding-National Science and Technology Major Project(2023ZD04076)+1 种基金the China Agriculture Research System of Maize(CARS-02-13)the Innovation Program of the Chinese Academy of Agricultural Sciences.
文摘Understanding the role of heterotic genes in contributing to heterosis is essential for advancing hybrid breeding.We analyzed plant height(PH),ear height(EH),and transcriptomic data from a maize hybrid pop-ulation.Genome-wide association studies(GWASs)revealed that dominance effects of quantitative trait loci(QTLs)play a significant role in hybrid traits and mid-parent heterosis.By integrating GWAS,expression GWAS(eGWAS),and module eGWAS analysis,we prioritized six candidate heterotic genes underlying six QTLs,including one QTL that spans the bZIP29 gene.In the hybrid population,bZIP29 exhibits additive expression and dominance effects for both hybrid traits and mid-parent heterosis,with its favorable allele correlating positively with PH and EH.bZIP29 demonstrates dominance or over-dominance patterns in hy-brids derived from crosses between transgenic and wild-type lines,contingent upon its expression.A tsCUT&Tag assay revealed that bZIP29 protein binds directly to a gene regulated by its associated expres-sion QTL(eQTL)and six genes within expression modules governed by its associated module-eQTLs(meQTLs).Regulatory networks involving bZIP29 are more extensive in hybrid subpopulations than in the parental population.This study offers insights into key heterotic genes and networks that underpin the robust growth of hybrid maize.
基金supported by the National Natural Science Foundation of China(32321005).
文摘Maize(Zea mays L.)is not only an important cereal crop,but also a model plant species for genetic,cytologic,genomic,and molecular studies.Maize possesses tremendous phenotypic and genetic diversity.During the past few decades,researchers have made significant advances in multiple areas,including the genomic compositions and variations of maize and its ancestors,the genetic and genomic bases of maize domestication and evolution,the genetic architecture of various agronomic traits(yield,quality,biotic and abiotic stress responses,nutrient use efficiency,fertility and heterosis),and the development of novel molecular breeding technologies.In this review,we summarize these research achievements and provide a perspective for future maize research and breeding.
基金supported by Biological Breeding-National Science and Technology Major Project(no.2023ZD04070,W.Z.)the National Key Research and Development Program,Ministry of Science and Technology of China(no.2022YFD1201802,W.Z.)+1 种基金the National Natural Science Foundation of China(no.32472499,W.Z.)the Pinduoduo-China Agricultural University Research Fund(no.PC2023A01005,Y.-L.P.).
文摘Maize(Zea mays)is one of the most important crops in the world,but its yield and quality are seriously affected by diverse diseases.Identifying broad-spectrum resistance genes is crucial for developing effective strategies to control the disease in maize.In a genome-wide study in maize,we identified a G-type lectin receptor kinase ZmLecRK1,as a new resistance protein against Pythium aphanidermatum,one of the causal pathogens of stalk rot in maize.Genetic analysis showed that the specific ZmLecRK1 allele can confer resistance to multiple pathogens in maize.The cell death and disease resistance phenotype mediated by the resistant variant of ZmLecRK1 requires the co-receptor ZmBAK1.A naturally occurring A404S variant in the extracellular domain of ZmLecRK1 determines the ZmLecRK1-ZmBAK1 interaction and the formation of ZmLecRK1-related protein complexes.Interestingly,the ZmLecRK1 susceptible variant was found to possess the amino acid S404 that is present in the ancestral variants of ZmLecRK1 and conserved among the majority of grass species,while the resistance variant of ZmLecRK1 with A404 is only present in a few maize inbred lines.Substitution of S by A at position 404 in ZmLecRK1-like proteins of sorghum and rice greatly enhances their ability to induce cell death.Further transcriptomic analysis reveals that ZmLecRK1 likely regulates gene expression related to the pathways in cell wall organization or biogenesis in response to pathogen infection.Taken together,these results suggest that the ZmLecRK1 resistance variant enhances its binding affinity to the co-receptor ZmBAK1,thereby enhancing the formation of active complexes for defense in maize.Our work highlights the biotechnological potential for generating disease-resistant crops by precisely modulating the activity of ZmLecRK1 and its homologs through targeted base editing.
基金supported by Biological Breeding-National Science and Technology Major Project of China(2023ZD0407104)the National Natural Science Foundation of China(32272025 and 31730011)the Pinduoduo-China Agricultural University Research Fund(PC2023B01001),and the Chinese Universities Scientific Fund.
文摘Understanding how maize(Zea mays)responds to cold stress is crucial for facilitating breeding programs of cold-tolerant varieties.Despite extensive utilization of the genome-wide association study(GWAs)approach for exploring favorable natural alleles associated with maize cold tolerance,few studies have successfully identified candidate genes that contribute to maize cold tolerance.In this study,we used a diverse panel of inbred maize lines collected from different germplasm sources to perform a GWAS on var-iations in the relative injured area of maize true leaves during cold stress-a trait very closely correlated with maize cold tolerance.We identified HsF21,which encodes a B-class heat shock transcription factor(HSF)that positively regulates cold tolerance at both the seedling and germination stages.Natural varia-tions in the promoter of the cold-tolerant HSF21Hap1 allele led to increased HSF21 expression under cold stress by inhibiting binding of the basic leucine zipper bziP68 transcription factor,a negative regulator of cold tolerance.By integrating transcriptome deep sequencing,DNA affinity purification sequencing,and targeted lipidomic analysis,we revealed the function of HsF21 in regulating lipid metabolism homeo-stasis to modulate cold tolerance in maize.In addition,we found that HsF21 confers maize cold tolerance without incurring yield penalties.Collectively,this study establishes HsF21 as a key regulator that en-hances cold tolerance in maize,providing valuable genetic resources for breeding of cold-tolerant maize varieties.
基金supported by the National Natural Science Foundation of China(U21A20212)the China Postdoctoral Science Foundation(2021M701172)+1 种基金the Chinese Universities Scientific Fund(2022TC136,2023RC057)the Open Funds of the State Key Laboratory of Plant Physiology and Biochemistry(SKLPPBKF2113)。
文摘Maize(Zea mays)cultivation is strongly affected by both abiotic and biotic stress,leading to reduced growth and productivity.It has recently become clear that regulators of plant stress responses,including the phytohormones abscisic acid(ABA),ethylene(ET),and jasmonic acid(JA),together with reactive oxygen species(ROS),shape plant growth and development.Beyond their well established functions in stress responses,these molecules play crucial roles in balancing growth and defense,which must be finely tuned to achieve high yields in crops while maintaining some level of defense.In this review,we provide an in-depth analysis of recent research on the developmental functions of stress regulators,focusing specifically on maize.By unraveling the contributions of these regulators to maize development,we present new avenues for enhancing maize cultivation and growth while highlighting the potential risks associated with manipulating stress regulators to enhance grain yields in the face of environmental challenges.
基金supported by grants from the STI 2030-Major Projects,China(2022ZD040190101,2022ZD040190502)the National Natural Science Foundation of China(32072130,32272162 and 31701437)+1 种基金the Project of Sanya Yazhou Bay Science and Technology City,China(SCKJ-JYRC-2023-64)the 2115 Talent Development Program of China Agricultural University,and the China Agriculture Research System(CARS-02-13)。
文摘The seed storage materials accumulate during seed development,and are essential for seed germination and seedling establishment.Here we employed two bi-parental populations of an F2:3 population developed from a cross of improved 220(I220,small seeds with low starch)and PH4CV(large seeds with high starch),as well as recombinant-inbred lines(RILs)of X178(high starch)and its improved introgression line I178(low starch),to identify the genes that control seed storage materials.We identified a total of 12 QTLs for starch,protein and oil,which explained 3.44-10.79%of the phenotypic variances.Among them,qSTA2-1 identified in F2:3 and qSTA2-2 identified in the RILs partially overlapped at an interval of 7.314-9.554 Mb,and they explained 3.44-10.21%of the starch content variation,so they were selected for further study.Fine mapping of qSTA2-2 with the backcrossed populations of ^(I220)/PH4CV in each generation narrowed it down to a 199.7 kb interval that contains 14 open reading frames(ORFs).Transcriptomic analysis of developing seeds from the near-isogenic lines(NILs)of ^(I220)/PH4CV(BC_(5)F_(2))showed that only 11 ORFs were expressed in 20 days after pollination(DAP)seeds.Five of them were upregulated and six of them were downregulated in NIL^(I220),and the differentially expressed genes(DEGs)between NIL^(I220) and NIL^(PH4CV) were enriched in starch metabolism,hormone signal transduction and glycosaminoglycan degradation.Of the eleven NIL^(I220) differential expressed ORFs,ORF4(Zm00001d002260)and ORF5(Zm00001d002261)carry 75%protein sequence similarity,both encodes an glycolate oxidase,were the possible candidates of qSTA2-2.Further analysis and validation indicated that mutation of the qSTA2-2 locus resulted in the dysfunction of ABA accumulation,the embryo/endosperm ratio and the starch and hormone levels.
