Rice and wheat provide nearly 40%of human calorie and protein requirements.They share a common ancestor and belong to the Poaceae(grass)family.Characterizing their genetic homology is crucial for developing new cultiv...Rice and wheat provide nearly 40%of human calorie and protein requirements.They share a common ancestor and belong to the Poaceae(grass)family.Characterizing their genetic homology is crucial for developing new cultivars with enhanced traits.Several wheat genes and gene families have been characterized based on their rice orthologs.Rice–wheat orthology can identify genetic regions that regulate similar traits in both crops.Rice–wheat comparative genomics can identify candidate wheat genes in a genomic region identified by association or QTL mapping,deduce their putative functions and biochemical pathways,and develop molecular markers for marker-assisted breeding.A knowledge of gene homology facilitates the transfer between crops of genes or genomic regions associated with desirable traits by genetic engineering,gene editing,or wide crossing.展开更多
Plant height is one of the most important agronomic traits associated with yield in maize.In this study,a gibberellins(GA)-insensitive dwarf mutant,m34,was screened from inbred line Ye478 by treatment with the chemica...Plant height is one of the most important agronomic traits associated with yield in maize.In this study,a gibberellins(GA)-insensitive dwarf mutant,m34,was screened from inbred line Ye478 by treatment with the chemical mutagen ethylmethanesulfonate(EMS).Compared to Ye478,m34 showed a dwarf phenotype with shorter internodes,and smaller leaf length and width,but with similar leaf number.Furthermore,m34 exhibited smaller guard cells in internodes than Ye478,suggesting that smaller cells might contribute to its dwarf phenotype.Genetic analysis indicated that the m34 dwarf phenotype was controlled by a recessive nuclear gene.An F2 population derived from a cross between m34 and B73 was used for mutational gene cloning and this gene was mapped to a chromosome region between umc2189 and umc1553 in chromosome 1 bin1.10,which harbored a previously identified dwarf gene Zm VP8.Sequencing analysis showed a nucleotide substitution(G1606 to A1606)in the sixth exon of ZmVP8,which resulted in an amino acid change(E531 to K531)from Ye478 to m34.This amino acid change resulted in anα-helix changing to aβ-sheet in the secondary protein structure and the‘SPEC’domain changed to a‘BOT1NT’domain in the tertiary protein structure.Taken together,these results suggested that m34 is a novel allelic mutant originally derived from Ye478 that is useful for further ZmVP8 functional analysis in maize.展开更多
Deep-sowing is an important method for avoiding drought stress in crop species,including maize.Identifying candidate genes is the groundwork for investigating the molecular mechanism underlying maize deep-sowing toler...Deep-sowing is an important method for avoiding drought stress in crop species,including maize.Identifying candidate genes is the groundwork for investigating the molecular mechanism underlying maize deep-sowing tolerance.This study evaluated four traits(mesocotyl length at 10 and 20 cm planting depths and seedling emergence rate on days 6 and 12)related to deep-sowing tolerance using a large maize population containing 386 inbred lines genotyped with 0.5 million high-quality single nucleotide polymorphisms(SNPs).The genomewide association study detected that 273 SNPs were in linkage disequilibrium(LD)with the genetic basis of maize deep-sowing tolerance.The RNA-sequencing analysis identified 1944 and 2098 differentially expressed genes(DEGs)in two comparisons,which shared 281 DEGs.By comparing the genomic locations of the 273 SNPs with those of the 281 DEGs,we identified seven candidate genes,of which GRMZM2G119769 encoded a sucrose non-fermenting 1 kinase interactor-like protein.GRMZM2G119769 was selected as the candidate gene because its homologs in other plants were related to organ length,auxin,or light response.Candidate gene association mapping revealed that natural variations in GRMZM2G119769 were related to phenotypic variations in maize mesocotyl length.Gene expression of GRMZM2G119769 was higher in deep-sowing tolerant inbred lines.These results suggest that GRMZM2G119769 is the most likely candidate gene.This study provides information on the deep-sowing tolerance of maize germplasms and identifies candidate genes,which would be useful for further research on maize deep-sowing tolerance.展开更多
Gene resources associated with plant stature and flowering time are invaluable for maize breeding.In this study,using an F2:3population derived from a natural semi-dwarf mutant grmm and a normal inbred line Si 273,we ...Gene resources associated with plant stature and flowering time are invaluable for maize breeding.In this study,using an F2:3population derived from a natural semi-dwarf mutant grmm and a normal inbred line Si 273,we identified a major pleiotropic QTL on the distal long arm of chromosome 1(qPH1_dla),and found that qPH1_dla controlled plant height,flowering time,ear and yield traits.qPH1_dla was finemapped to a 16 kb interval containing ZmAMP1,which was annotated as a glutamate carboxypeptidase.Allelism tests using two independent allelic mutants confirmed that ZmAMP1 was the causal gene.Realtime quantitative PCR and genomic sequence analysis suggested that a nonsynonymous mutation at the598th base of ZmAMP1 gene was the causal sequence variant for the dwarfism of grmm.This novel ZmAMP1 allele was named ZmAMP1_grmm.RNA sequencing using two pairs of near isogenic lines(NILs)showed that 84 up-regulated and 68 down-regulated genes in dwarf NILs were enriched in 15metabolic pathways.Finally,introgression of ZmAMP1_grmm into Zhengdan 958 and Xianyu 335 generated two improved F1lines.In field tests,they were semi-dwarf,early-flowering,lodging-resistant,and high-yielding under high-density planting conditions,suggesting that ZmAMP1_grmm is a promising Green Revolution gene for maize hybrid breeding.展开更多
文摘Rice and wheat provide nearly 40%of human calorie and protein requirements.They share a common ancestor and belong to the Poaceae(grass)family.Characterizing their genetic homology is crucial for developing new cultivars with enhanced traits.Several wheat genes and gene families have been characterized based on their rice orthologs.Rice–wheat orthology can identify genetic regions that regulate similar traits in both crops.Rice–wheat comparative genomics can identify candidate wheat genes in a genomic region identified by association or QTL mapping,deduce their putative functions and biochemical pathways,and develop molecular markers for marker-assisted breeding.A knowledge of gene homology facilitates the transfer between crops of genes or genomic regions associated with desirable traits by genetic engineering,gene editing,or wide crossing.
基金supported by the National Key R&D Program of China(2016YFD0101803)the earmarked fund for China Agriculture Research System(CARS-02-10)+1 种基金the National Natural Science Foundation of China(31771891)the Chinese University Scientific Fund(2015ZH001)
文摘Plant height is one of the most important agronomic traits associated with yield in maize.In this study,a gibberellins(GA)-insensitive dwarf mutant,m34,was screened from inbred line Ye478 by treatment with the chemical mutagen ethylmethanesulfonate(EMS).Compared to Ye478,m34 showed a dwarf phenotype with shorter internodes,and smaller leaf length and width,but with similar leaf number.Furthermore,m34 exhibited smaller guard cells in internodes than Ye478,suggesting that smaller cells might contribute to its dwarf phenotype.Genetic analysis indicated that the m34 dwarf phenotype was controlled by a recessive nuclear gene.An F2 population derived from a cross between m34 and B73 was used for mutational gene cloning and this gene was mapped to a chromosome region between umc2189 and umc1553 in chromosome 1 bin1.10,which harbored a previously identified dwarf gene Zm VP8.Sequencing analysis showed a nucleotide substitution(G1606 to A1606)in the sixth exon of ZmVP8,which resulted in an amino acid change(E531 to K531)from Ye478 to m34.This amino acid change resulted in anα-helix changing to aβ-sheet in the secondary protein structure and the‘SPEC’domain changed to a‘BOT1NT’domain in the tertiary protein structure.Taken together,these results suggested that m34 is a novel allelic mutant originally derived from Ye478 that is useful for further ZmVP8 functional analysis in maize.
基金supported by the National Key R&D Program of China(2018YFD0100903)the China Agriculture Research System of MOF and MARA(CARS-02-13)the Natural Science Fund of Liaoning Province,China(20170540806)。
文摘Deep-sowing is an important method for avoiding drought stress in crop species,including maize.Identifying candidate genes is the groundwork for investigating the molecular mechanism underlying maize deep-sowing tolerance.This study evaluated four traits(mesocotyl length at 10 and 20 cm planting depths and seedling emergence rate on days 6 and 12)related to deep-sowing tolerance using a large maize population containing 386 inbred lines genotyped with 0.5 million high-quality single nucleotide polymorphisms(SNPs).The genomewide association study detected that 273 SNPs were in linkage disequilibrium(LD)with the genetic basis of maize deep-sowing tolerance.The RNA-sequencing analysis identified 1944 and 2098 differentially expressed genes(DEGs)in two comparisons,which shared 281 DEGs.By comparing the genomic locations of the 273 SNPs with those of the 281 DEGs,we identified seven candidate genes,of which GRMZM2G119769 encoded a sucrose non-fermenting 1 kinase interactor-like protein.GRMZM2G119769 was selected as the candidate gene because its homologs in other plants were related to organ length,auxin,or light response.Candidate gene association mapping revealed that natural variations in GRMZM2G119769 were related to phenotypic variations in maize mesocotyl length.Gene expression of GRMZM2G119769 was higher in deep-sowing tolerant inbred lines.These results suggest that GRMZM2G119769 is the most likely candidate gene.This study provides information on the deep-sowing tolerance of maize germplasms and identifies candidate genes,which would be useful for further research on maize deep-sowing tolerance.
基金supported by the Hainan Provincial Joint Project of Sanya Yazhou Bay Science and Technology City(320LH043)the Key Scientific and Technological Research Project in Henan Province(222102110091)+2 种基金the China Agriculture Research System(CARS-02-13)the Hainan Yazhou Bay Seed Laboratory(B21HJ0223)the Chinese Academy of Agricultural Sciences(CAAS)Innovation Project(CAAS-ZDRW202004)。
文摘Gene resources associated with plant stature and flowering time are invaluable for maize breeding.In this study,using an F2:3population derived from a natural semi-dwarf mutant grmm and a normal inbred line Si 273,we identified a major pleiotropic QTL on the distal long arm of chromosome 1(qPH1_dla),and found that qPH1_dla controlled plant height,flowering time,ear and yield traits.qPH1_dla was finemapped to a 16 kb interval containing ZmAMP1,which was annotated as a glutamate carboxypeptidase.Allelism tests using two independent allelic mutants confirmed that ZmAMP1 was the causal gene.Realtime quantitative PCR and genomic sequence analysis suggested that a nonsynonymous mutation at the598th base of ZmAMP1 gene was the causal sequence variant for the dwarfism of grmm.This novel ZmAMP1 allele was named ZmAMP1_grmm.RNA sequencing using two pairs of near isogenic lines(NILs)showed that 84 up-regulated and 68 down-regulated genes in dwarf NILs were enriched in 15metabolic pathways.Finally,introgression of ZmAMP1_grmm into Zhengdan 958 and Xianyu 335 generated two improved F1lines.In field tests,they were semi-dwarf,early-flowering,lodging-resistant,and high-yielding under high-density planting conditions,suggesting that ZmAMP1_grmm is a promising Green Revolution gene for maize hybrid breeding.
