Drought is the most important environmental stress affecting agriculture worldwide. Exploiting yield potential and maintaining yield stability of crops in water-limited environments are urgent tasks that must be under...Drought is the most important environmental stress affecting agriculture worldwide. Exploiting yield potential and maintaining yield stability of crops in water-limited environments are urgent tasks that must be undertaken in order to guarantee food supply for the increasing world population. Tremendous efforts have been devoted to identifying key regulators in plant drought response through genetic, molecular, and biochemical studies using, in most cases, the model species Arabidopsis thaliana. However, only a small portion of these regulators have been explored as potential candidate genes for their application in the improvement of drought tolerance in crops. Based on biological functions, these genes can be classified into the following three categories： （1） stress-responsive transcriptional regulation （e.g. DREB1, AREB, NF-YB）; （2） post-transcriptional RNA or protein modifications such as phosphorylation/dephosphorylation （e.g. SnRK2, ABI1） and farnesylation （e.g. ERA1）; and （3） osomoprotectant metabolism or molecular chaperones （e.g. CspB）. While continuing down the path to discovery of new target genes, serious efforts are also focused on fine-tuning the expression of the known candidate genes for stress tolerance in specific temporal and spatial patterns to avoid negative effects in plant growth and development. These efforts are starting to bear fruit by showing yield improvements in several crops under a variety of water-deprivation conditions. As most such evaluations have been performed under controlled growth environments, a gap still remains between early success in the laboratory and the application of these techniques to the elite cultivars of staple crops in the field. Nevertheless, significant progress has been made in the identification of signaling pathways and master regulators for drought tolerance. The knowledge acquired will facilitate the genetic engineering of single or multiple targets and quantitative trait loci in key crops to create commercialrade cultiv展开更多
Trehalose Is a nonreduclng dlsaccharlde of glucose that functions as a protectant In the stabilization of blologlcal structures and enhances stress tolerance to abiotic stresses in organisms. We report here the expres...Trehalose Is a nonreduclng dlsaccharlde of glucose that functions as a protectant In the stabilization of blologlcal structures and enhances stress tolerance to abiotic stresses in organisms. We report here the expression of a Grlfola frondosa trehalose synthase （TSase） gene for Improving drought tolerance In sugarcane （Saccharum offlclnarum L.）. The expression of the transgene was under the control of two tandem copies of the CaMV35S promoter and transferred Into sugarcane by Agrobacterium tumefaciens EHA105. The transgenlc plants accumulated high levels of trehalose, up to 8.805-12.863 mg/g fresh weight, whereas It was present at undetectable level in nontransgenlc plants. It has been reported that transgenlc plants transformed with Escherlchla coil TPS （trehalose-6-phosphatesynthase） and/or TPP （trehalose-6-phosphate phosphatase） are severely stunted and have root morphologlc alterations. Interestingly, our transgenlc sugarcane plants had no obvious morphological changes and no growth Inhibition in the field. Trehalose accumulation in 35S-35S：TSase plants resulted In In- creased drought tolerance, as shown by the drought and the drought physiological Indexes, such as the rate of bound water/free water, plasma membrane permeability, malondlaldehyde content, chlorophyll a and b contents, and activity of SOD and POD of the excised leaves. These results suggest that transgenlc plants transformed with the TSase gene can accumulate high levels of trehalose and have enhanced tolerance to drought.展开更多
Trehalose is a non-reducing disaccharide of glucose that functions as a protectant in the stabilization of biological structures and enhances the tolerance of organisms to abiotic stress. In the present study, we repo...Trehalose is a non-reducing disaccharide of glucose that functions as a protectant in the stabilization of biological structures and enhances the tolerance of organisms to abiotic stress. In the present study, we report on the expression of the Grifola frondosa Fr. Trehalose synthase (Tsase) gene for manipulating abiotic stress tolerance in tobacco (Nicotiana tabaccum L.). The expression of the transgene was under the control of two tandem copies of the CaMV3 5 S promoter and was transferred into tobacco by Agrobacterium tumefaciens EHA105. Compared with non-transgenic plants, transgenic plants were able to accumulate high levels of products of trehalose, which were increased up to 2.126–2.556 mg/g FW, although levels were undetectable in non-transgenic plants. This level of trehalose in transgenic plants was 400-fold higher than that of transgenic tobacco plants cotransformed with Escherichia coli TPS and TPP on independent expression cassettes, twofold higher than that of transgenic rice plants transformed with a bi functional fusion gene (TPSP) of the trehalose-6-phosphate (T-6-P) synthase (TPS) and T-6-P phosphatase (TPP) of E. coli, and 12-fold higher than that of transgenic tobacco plants transformed the yeast TPS1 gene. It has been reported that transgenic plants with E. coli TPS and/or TPP were severely stunted and had morphological alterations of their roots. Interestingly, our transgenic plants have obvious morphological changes, including thick and deep-coloured leaves, but show no growth inhibition; moreover, these morphological changes can restore to normal type in T2 progenies. Trehalose accumulation in 35S–35S:Tsase plants resulted in increased tolerance to drought and salt, as shown by the results of tests on drought, salt tolerance, and drought physiological indices, such as water content in excised leaves, malondialdehyde content, chlorophyll a and b contents, and the activity of superoxide dismutase and peroxidase in excised leaves. These results suggest that transgenic plants transformed w展开更多
This review updates the present status of the field of molecular markers and marker-assisted selection(MAS),using the example of drought tolerance in barley.The accuracy of selected quantitative trait loci(QTLs),candi...This review updates the present status of the field of molecular markers and marker-assisted selection(MAS),using the example of drought tolerance in barley.The accuracy of selected quantitative trait loci(QTLs),candidate genes and suggested markers was assessed in the barley genome cv.Morex.Six common strategies are described for molecular marker development,candidate gene identification and verification,and their possible applications in MAS to improve the grain yield and yield components in barley under drought stress.These strategies are based on the following five principles:(1)Molecular markers are designated as genomic‘tags’,and their‘prediction’is strongly dependent on their distance from a candidate gene on genetic or physical maps;(2)plants react differently under favourable and stressful conditions or depending on their stage of development;(3)each candidate gene must be verified by confirming its expression in the relevant conditions,e.g.,drought;(4)the molecular marker identified must be validated for MAS for tolerance to drought stress and improved grain yield;and(5)the small number of molecular markers realized for MAS in breeding,from among the many studies targeting candidate genes,can be explained by the complex nature of drought stress,and multiple stress-responsive genes in each barley genotype that are expressed differentially depending on many other factors.展开更多
Background:Cotton is mainly grown for its natural fiber and edible oil.The fiber obtained from cotton is the indispensable raw material for the textile industries.The ever changing climatic condition,threatens cotton ...Background:Cotton is mainly grown for its natural fiber and edible oil.The fiber obtained from cotton is the indispensable raw material for the textile industries.The ever changing climatic condition,threatens cotton production due to a lack of sufficient water for its cultivation.Effects of drought stress are estimated to affect more than 50%of the cotton growing regions.To elucidate the drought tolerance phenomenon in cotton,a backcross population was developed from G.tomentosum,a drought tolerant donor parent and G.hirsutum which is highly susceptible to drought stress.Results:A genetic map of 10888 SNP markers was developed from 200 BC_2F_2 populations.The map spanned 4191.3 centi-Morgan(c M),with an average distance of 0.1047 c M,covering 51%and 49%of At and Dt sub genomes,respectively.Thirty stable Quantitative trait loci(QTLs)were detected,in which more than a half were detected in the At subgenome.Eighty-nine candidate genes were mined within the QTL regions for three traits:cell membrane stability(CMS),saturated leaf weight(SLW)and chlorophyll content.The genes had varied physiochemical properties.A majority of the genes were interrupted by introns,and only 15 genes were intronless,accounting for 17%of the mined genes.The genes were found to be involved molecular function(MF),cellular component(CC)and biological process(BP),which are the main gene ontological(GO)functions.A number of mi RNAs were detected,such as mi R164,which is associated with NAC and MYB genes,with a profound role in enhancing drought tolerance in plants.Through RT-q PCR analysis,5 genes were found to be the key genes involved in enhancing drought tolerance in cotton.Wild cotton harbors a number of favorable alleles,which can be exploited to aid in improving the narrow genetic base of the elite cotton cultivars.The detection of 30 stable QTLs and 89 candidate genes found to be contributed by the donor parent,G.tomentosum,showed the significant genes harbored by the wild progenitors which can be exploited in developing more robust cott展开更多
Drought is one of the most important environmental constraints limiting plant growth, development and crop yield. Many drought-inducible genes have been identified by molecular and genomic analyses in Arabidopsis, ric...Drought is one of the most important environmental constraints limiting plant growth, development and crop yield. Many drought-inducible genes have been identified by molecular and genomic analyses in Arabidopsis, rice and other crops. To better understand reaction mechanism of plant to drought tolerance, we mainly focused on introducing the research of transcription factors （TFs） in signal transduction and regulatory network of gene expression conferring drought. A TF could bind multiple target genes to increase one or more kinds of stress tolerance. Sometimes, several TFs might act together with a target gene. So drought-tolerance genes or TFs might respond to high-salinity, cold or other stresses. The crosstalk of multiple stresses signal pathways is a crucial aspect of understanding stress signaling.展开更多
文摘Drought is the most important environmental stress affecting agriculture worldwide. Exploiting yield potential and maintaining yield stability of crops in water-limited environments are urgent tasks that must be undertaken in order to guarantee food supply for the increasing world population. Tremendous efforts have been devoted to identifying key regulators in plant drought response through genetic, molecular, and biochemical studies using, in most cases, the model species Arabidopsis thaliana. However, only a small portion of these regulators have been explored as potential candidate genes for their application in the improvement of drought tolerance in crops. Based on biological functions, these genes can be classified into the following three categories： （1） stress-responsive transcriptional regulation （e.g. DREB1, AREB, NF-YB）; （2） post-transcriptional RNA or protein modifications such as phosphorylation/dephosphorylation （e.g. SnRK2, ABI1） and farnesylation （e.g. ERA1）; and （3） osomoprotectant metabolism or molecular chaperones （e.g. CspB）. While continuing down the path to discovery of new target genes, serious efforts are also focused on fine-tuning the expression of the known candidate genes for stress tolerance in specific temporal and spatial patterns to avoid negative effects in plant growth and development. These efforts are starting to bear fruit by showing yield improvements in several crops under a variety of water-deprivation conditions. As most such evaluations have been performed under controlled growth environments, a gap still remains between early success in the laboratory and the application of these techniques to the elite cultivars of staple crops in the field. Nevertheless, significant progress has been made in the identification of signaling pathways and master regulators for drought tolerance. The knowledge acquired will facilitate the genetic engineering of single or multiple targets and quantitative trait loci in key crops to create commercialrade cultiv
基金National Natural Science Foundation of China （30160045）,the Hainan Provincial Natural Science Foundation of China （30101）, the 948 Project of the Ministry of Agriculture, China （2003-Q06） and the Yunnan Provincial Natural Science Foundation of China （2002C0002M）.
文摘Trehalose Is a nonreduclng dlsaccharlde of glucose that functions as a protectant In the stabilization of blologlcal structures and enhances stress tolerance to abiotic stresses in organisms. We report here the expression of a Grlfola frondosa trehalose synthase （TSase） gene for Improving drought tolerance In sugarcane （Saccharum offlclnarum L.）. The expression of the transgene was under the control of two tandem copies of the CaMV35S promoter and transferred Into sugarcane by Agrobacterium tumefaciens EHA105. The transgenlc plants accumulated high levels of trehalose, up to 8.805-12.863 mg/g fresh weight, whereas It was present at undetectable level in nontransgenlc plants. It has been reported that transgenlc plants transformed with Escherlchla coil TPS （trehalose-6-phosphatesynthase） and/or TPP （trehalose-6-phosphate phosphatase） are severely stunted and have root morphologlc alterations. Interestingly, our transgenlc sugarcane plants had no obvious morphological changes and no growth Inhibition in the field. Trehalose accumulation in 35S-35S：TSase plants resulted In In- creased drought tolerance, as shown by the drought and the drought physiological Indexes, such as the rate of bound water/free water, plasma membrane permeability, malondlaldehyde content, chlorophyll a and b contents, and activity of SOD and POD of the excised leaves. These results suggest that transgenlc plants transformed with the TSase gene can accumulate high levels of trehalose and have enhanced tolerance to drought.
文摘Trehalose is a non-reducing disaccharide of glucose that functions as a protectant in the stabilization of biological structures and enhances the tolerance of organisms to abiotic stress. In the present study, we report on the expression of the Grifola frondosa Fr. Trehalose synthase (Tsase) gene for manipulating abiotic stress tolerance in tobacco (Nicotiana tabaccum L.). The expression of the transgene was under the control of two tandem copies of the CaMV3 5 S promoter and was transferred into tobacco by Agrobacterium tumefaciens EHA105. Compared with non-transgenic plants, transgenic plants were able to accumulate high levels of products of trehalose, which were increased up to 2.126–2.556 mg/g FW, although levels were undetectable in non-transgenic plants. This level of trehalose in transgenic plants was 400-fold higher than that of transgenic tobacco plants cotransformed with Escherichia coli TPS and TPP on independent expression cassettes, twofold higher than that of transgenic rice plants transformed with a bi functional fusion gene (TPSP) of the trehalose-6-phosphate (T-6-P) synthase (TPS) and T-6-P phosphatase (TPP) of E. coli, and 12-fold higher than that of transgenic tobacco plants transformed the yeast TPS1 gene. It has been reported that transgenic plants with E. coli TPS and/or TPP were severely stunted and had morphological alterations of their roots. Interestingly, our transgenic plants have obvious morphological changes, including thick and deep-coloured leaves, but show no growth inhibition; moreover, these morphological changes can restore to normal type in T2 progenies. Trehalose accumulation in 35S–35S:Tsase plants resulted in increased tolerance to drought and salt, as shown by the results of tests on drought, salt tolerance, and drought physiological indices, such as water content in excised leaves, malondialdehyde content, chlorophyll a and b contents, and the activity of superoxide dismutase and peroxidase in excised leaves. These results suggest that transgenic plants transformed w
基金supported by Bolashak International Fellowships,Center for International Programs,Ministry of Education and Science,KazakhstanAP14869777 supported by the Ministry of Education and Science,KazakhstanResearch Projects BR10764991 and BR10765000 supported by the Ministry of Agriculture,Kazakhstan。
文摘This review updates the present status of the field of molecular markers and marker-assisted selection(MAS),using the example of drought tolerance in barley.The accuracy of selected quantitative trait loci(QTLs),candidate genes and suggested markers was assessed in the barley genome cv.Morex.Six common strategies are described for molecular marker development,candidate gene identification and verification,and their possible applications in MAS to improve the grain yield and yield components in barley under drought stress.These strategies are based on the following five principles:(1)Molecular markers are designated as genomic‘tags’,and their‘prediction’is strongly dependent on their distance from a candidate gene on genetic or physical maps;(2)plants react differently under favourable and stressful conditions or depending on their stage of development;(3)each candidate gene must be verified by confirming its expression in the relevant conditions,e.g.,drought;(4)the molecular marker identified must be validated for MAS for tolerance to drought stress and improved grain yield;and(5)the small number of molecular markers realized for MAS in breeding,from among the many studies targeting candidate genes,can be explained by the complex nature of drought stress,and multiple stress-responsive genes in each barley genotype that are expressed differentially depending on many other factors.
基金program was financially sponsored by the National Natural Science Foundation of China(31671745,31530053)the National key research and development plan(2016YFD0100306)。
文摘Background:Cotton is mainly grown for its natural fiber and edible oil.The fiber obtained from cotton is the indispensable raw material for the textile industries.The ever changing climatic condition,threatens cotton production due to a lack of sufficient water for its cultivation.Effects of drought stress are estimated to affect more than 50%of the cotton growing regions.To elucidate the drought tolerance phenomenon in cotton,a backcross population was developed from G.tomentosum,a drought tolerant donor parent and G.hirsutum which is highly susceptible to drought stress.Results:A genetic map of 10888 SNP markers was developed from 200 BC_2F_2 populations.The map spanned 4191.3 centi-Morgan(c M),with an average distance of 0.1047 c M,covering 51%and 49%of At and Dt sub genomes,respectively.Thirty stable Quantitative trait loci(QTLs)were detected,in which more than a half were detected in the At subgenome.Eighty-nine candidate genes were mined within the QTL regions for three traits:cell membrane stability(CMS),saturated leaf weight(SLW)and chlorophyll content.The genes had varied physiochemical properties.A majority of the genes were interrupted by introns,and only 15 genes were intronless,accounting for 17%of the mined genes.The genes were found to be involved molecular function(MF),cellular component(CC)and biological process(BP),which are the main gene ontological(GO)functions.A number of mi RNAs were detected,such as mi R164,which is associated with NAC and MYB genes,with a profound role in enhancing drought tolerance in plants.Through RT-q PCR analysis,5 genes were found to be the key genes involved in enhancing drought tolerance in cotton.Wild cotton harbors a number of favorable alleles,which can be exploited to aid in improving the narrow genetic base of the elite cotton cultivars.The detection of 30 stable QTLs and 89 candidate genes found to be contributed by the donor parent,G.tomentosum,showed the significant genes harbored by the wild progenitors which can be exploited in developing more robust cott
基金Supported by Cultivation of New Varieties of Genetically Modified Major Projects (2011ZX08004-005)Soybean Industry Technology System(CARS-04-PS08)
文摘Drought is one of the most important environmental constraints limiting plant growth, development and crop yield. Many drought-inducible genes have been identified by molecular and genomic analyses in Arabidopsis, rice and other crops. To better understand reaction mechanism of plant to drought tolerance, we mainly focused on introducing the research of transcription factors （TFs） in signal transduction and regulatory network of gene expression conferring drought. A TF could bind multiple target genes to increase one or more kinds of stress tolerance. Sometimes, several TFs might act together with a target gene. So drought-tolerance genes or TFs might respond to high-salinity, cold or other stresses. The crosstalk of multiple stresses signal pathways is a crucial aspect of understanding stress signaling.
