Wheat is one of the major food crops in the world.Functional validation of the genes in increasing the grain yield of wheat by genetic engineering is essential for feeding the ever-growing global population.This study...Wheat is one of the major food crops in the world.Functional validation of the genes in increasing the grain yield of wheat by genetic engineering is essential for feeding the ever-growing global population.This study investigated the role of ABP7,a bHLH transcription factor from maize involved in kernel development,in regulating grain yield-related traits in transgenic wheat.Molecular characterization showed that transgenic lines HB123 and HB287 contained multicopy integration of ABP7 in the genome with higher transgene expression.At the same time,QB205 was a transgenic event of single copy insertion with no significant difference in ABP7 expression compared to wild-type(WT) plants.Phenotyping under field conditions showed that ABP7 over-expressing transgenic lines HB123 and HB287 exhibited improved grain yield-related traits(e.g.,grain number per spike,grain weight per spike,thousand-grain weight,grain length,and grain width) and increased grain yield per plot,compared to WT plants,whereas line QB205 did not.In addition,total chlorophyll,chlorophyll a,chlorophyll b,and total soluble sugars were largely increased in the flag leaves of both HB123and HB287 transgenic lines compared to the WT.These results strongly suggest that ABP7 positively regulates yieldrelated traits and plot grain yield in transgenic wheat.Consequently,ABP7 can be utilized in wheat breeding for grain yield improvement.展开更多
Abiotic stresses, especially drought and salt, severely affect maize production, which is one of the most important cereal crops in the world. Breeding stress-tolerant maize through biotechnology is urgently needed to...Abiotic stresses, especially drought and salt, severely affect maize production, which is one of the most important cereal crops in the world. Breeding stress-tolerant maize through biotechnology is urgently needed to maintain maize production. Therefore, it is important to identify new genes that can enhance both drought and salt stress tolerance for molecular breeding. In this study, we identified a maize ABA （abscisic acid）-responsive element （ABRE） binding protein from a 17-day post-pollination （dpp） maize embryo cDNA library by yeast one-hybrid screen using the ABRE2 sequence of the maize Cat1 gene as bait. This protein, designated, ABRE binding protein 2 （ABP2）, belongs to the bZIP transcription factor family. Endogenous expression of ABP2 in maize can be detected in different tissues at various development stages, and can be induced by drought, salt, reactive oxygen species （ROS）-generating agents, and ABA treatment. Constitutive expression of ABP2 in transgenic Arabidopsis plants enhanced tolerance to drought and salt stress, and increased sensitivity to ABA. In exploring the mechanism by which ABP2 can stimulate abiotic stress tolerance, we found that ROS levels were reduced and expression of stress-responsive and carbon metabolism-related genes was enhanced by constitutive ABP2 expression in transgenic plants. In Short, we identified a maize bZIP transcription factor which can enhance both drought and salt tolerance of plants.展开更多
Increasing the planting density is one way to enhance grain production in maize.However,high planting density brings about growth and developmental defects such as barrenness,which is the major factor limiting grain y...Increasing the planting density is one way to enhance grain production in maize.However,high planting density brings about growth and developmental defects such as barrenness,which is the major factor limiting grain yield.In this study,the barrenness was characterized in an association panel comprising 280 inbred lines under normal(67500 plants ha–1,ND)and high(120000 plants ha–1,HD)planting densities in 2017 and 2018.The population was genotyped using 776254 single nucleotide polymorphism(SNP)markers with criteria of minor allele frequency>5%and<20%missing data.A genome-wide association study(GWAS)was conducted for barrenness under ND and HD,as well as the barrenness ratio(HD/ND),by applying a Mixed Linear Model that controls both population structure and relative kinship(Q+K).In total,20 SNPs located in nine genes were significantly(P<6.44×10–8)associated with barrenness under the different planting densities.Among them,seven SNPs for barrenness at ND and HD were located in two genes,four of which were common under both ND and HD.In addition,13 SNPs for the barrenness ratio were located in seven genes.A complementary pathway analysis indicated that the metabolic pathways of amino acids,such as glutamate and arginine,and the mitogen-activated protein kinase(MAPK)signaling pathway might play important roles in tolerance to high planting density.These results provide insights into the genetic basis of high planting density tolerance and will facilitate high yield maize breeding.展开更多
文摘Wheat is one of the major food crops in the world.Functional validation of the genes in increasing the grain yield of wheat by genetic engineering is essential for feeding the ever-growing global population.This study investigated the role of ABP7,a bHLH transcription factor from maize involved in kernel development,in regulating grain yield-related traits in transgenic wheat.Molecular characterization showed that transgenic lines HB123 and HB287 contained multicopy integration of ABP7 in the genome with higher transgene expression.At the same time,QB205 was a transgenic event of single copy insertion with no significant difference in ABP7 expression compared to wild-type(WT) plants.Phenotyping under field conditions showed that ABP7 over-expressing transgenic lines HB123 and HB287 exhibited improved grain yield-related traits(e.g.,grain number per spike,grain weight per spike,thousand-grain weight,grain length,and grain width) and increased grain yield per plot,compared to WT plants,whereas line QB205 did not.In addition,total chlorophyll,chlorophyll a,chlorophyll b,and total soluble sugars were largely increased in the flag leaves of both HB123and HB287 transgenic lines compared to the WT.These results strongly suggest that ABP7 positively regulates yieldrelated traits and plot grain yield in transgenic wheat.Consequently,ABP7 can be utilized in wheat breeding for grain yield improvement.
基金supported by the National Natural Science Foundation of China (30870202)the National Key Research and Development Program of China (2016YFD0101002)the National Special Program for Genetically Modified Organism (GMO) Development of China (2016ZX08003004)
文摘Abiotic stresses, especially drought and salt, severely affect maize production, which is one of the most important cereal crops in the world. Breeding stress-tolerant maize through biotechnology is urgently needed to maintain maize production. Therefore, it is important to identify new genes that can enhance both drought and salt stress tolerance for molecular breeding. In this study, we identified a maize ABA （abscisic acid）-responsive element （ABRE） binding protein from a 17-day post-pollination （dpp） maize embryo cDNA library by yeast one-hybrid screen using the ABRE2 sequence of the maize Cat1 gene as bait. This protein, designated, ABRE binding protein 2 （ABP2）, belongs to the bZIP transcription factor family. Endogenous expression of ABP2 in maize can be detected in different tissues at various development stages, and can be induced by drought, salt, reactive oxygen species （ROS）-generating agents, and ABA treatment. Constitutive expression of ABP2 in transgenic Arabidopsis plants enhanced tolerance to drought and salt stress, and increased sensitivity to ABA. In exploring the mechanism by which ABP2 can stimulate abiotic stress tolerance, we found that ROS levels were reduced and expression of stress-responsive and carbon metabolism-related genes was enhanced by constitutive ABP2 expression in transgenic plants. In Short, we identified a maize bZIP transcription factor which can enhance both drought and salt tolerance of plants.
基金the 2020 Research Program of Sanya Yazhou Bay Science and Technology City,China(SKJC-2020-02-005)the Agricultural Science and Technology Innovation Program(ASTIP)of Chinese Academy of Agricultural Sciences(CAAS-ZDRW202004 and CAAS-ZDRW202109).
文摘Increasing the planting density is one way to enhance grain production in maize.However,high planting density brings about growth and developmental defects such as barrenness,which is the major factor limiting grain yield.In this study,the barrenness was characterized in an association panel comprising 280 inbred lines under normal(67500 plants ha–1,ND)and high(120000 plants ha–1,HD)planting densities in 2017 and 2018.The population was genotyped using 776254 single nucleotide polymorphism(SNP)markers with criteria of minor allele frequency>5%and<20%missing data.A genome-wide association study(GWAS)was conducted for barrenness under ND and HD,as well as the barrenness ratio(HD/ND),by applying a Mixed Linear Model that controls both population structure and relative kinship(Q+K).In total,20 SNPs located in nine genes were significantly(P<6.44×10–8)associated with barrenness under the different planting densities.Among them,seven SNPs for barrenness at ND and HD were located in two genes,four of which were common under both ND and HD.In addition,13 SNPs for the barrenness ratio were located in seven genes.A complementary pathway analysis indicated that the metabolic pathways of amino acids,such as glutamate and arginine,and the mitogen-activated protein kinase(MAPK)signaling pathway might play important roles in tolerance to high planting density.These results provide insights into the genetic basis of high planting density tolerance and will facilitate high yield maize breeding.
