ABA is one of the 5 phytohormones in higher plants, which is also the most important hormone that regulates higher plants in response to environmental stress, by ABA signal transduction. Understanding ABA signal trans...ABA is one of the 5 phytohormones in higher plants, which is also the most important hormone that regulates higher plants in response to environmental stress, by ABA signal transduction. Understanding ABA signal transduction at the molecular level is crucial to biology and ecology, and rational breeding complied with corresponding eco-environmental changes. Great advancements have taken place over the past 10 years by application of the Arabidopsis experimental system. Many components involved in ABA signal transduction have been isolated and identified and a clear overall picture of gene expression and control for this transduction has become an accepted fact. On the basis of the work in our laboratory, in conjunction with the data available at the moment, the authors have attempted to integrate ABA signal transduction pathways into a common one and give some insights into the relationship between ABA signal transduction and other hormone signal transduction pathways, with an emphasis upon the ABA signal transduction during higher plant seed development. A future challenge in this field is that different experimental systems are applied and various receptors and genes need to be characterized through the utilization of microarray chips.展开更多
A cDNA clone encoding an ABA-responsiveprotein HVA1,was isolated by differentialscreening from barley aleurone layers(Hong etal.).Expression of the HVA1 gene is shownto be developmentally regulated,organ-specif-ic,an... A cDNA clone encoding an ABA-responsiveprotein HVA1,was isolated by differentialscreening from barley aleurone layers(Hong etal.).Expression of the HVA1 gene is shownto be developmentally regulated,organ-specif-ic,and ABA-and stress-induced(Hong et展开更多
The phytohormone abscisic acid(ABA)plays an important role in plant growth and development,for example in seed dormancy and germination,as well as in plant responses to environmental stresses,such as drought and high ...The phytohormone abscisic acid(ABA)plays an important role in plant growth and development,for example in seed dormancy and germination,as well as in plant responses to environmental stresses,such as drought and high salinity.Previous studies have shown that ABA regulates the expression of genes with an ABA-responsive element(ABRE)and their corresponding physiological responses.Bioinformatics analysis identified a GRAM domain-containing gene family that has a multiple ABRE cis-element,which was termed the ABA-responsive protein(ABR)family.To analyze the function of the ABR family,we identified homozygous T-DNA insertion mutants and constructed abr1,2,3 double mutants and triple mutant.The abr1,abr2 and abr3single mutants showed a normal phenotype;however,the germination of seeds of the double mutants and triple mutant were insensitive to ABA,NaCl,mannitol and glucose.ABR1-GFP was distributed as a punctate structure in the cytosol and may be localized in the endomembrane system.The ABR2-GFP and ABR3-GFP proteins localized in the cytoplasm.In addition,ABR1,ABR2 and ABR3 were expressed in various tissues,and could be induced by several abiotic stresses,especially by ABA.The expressions of these genes were significantly suppressed in aba2,abi1 and abi2 null mutants.These results suggested that the ABR family may act downstream of ABI1 and ABI2 in the ABA signal transduction process in plants.展开更多
Pre‐harvest sprouting（PHS） seriously affects wheat yield and quality of the grain. ABI3 is a key factor in the activation of seed development and repression of germination in Arabidopsis. An ABI3‐interacting prot...Pre‐harvest sprouting（PHS） seriously affects wheat yield and quality of the grain. ABI3 is a key factor in the activation of seed development and repression of germination in Arabidopsis. An ABI3‐interacting protein（AIP2） could polyubiquitinate ABI3, impair seed dormancy and promote seed germination in Arabidopsis. In this study,two wheat AIP2 genes, TaAIP2A and TaAIP2B, were isolated.Subcellular localization assay and yeast two‐hybrid analysis revealed that TaAIP2A and TaAIP2B may function through interaction with wheat Viviporous‐1（TaVp1）. The transcripts TaAIP2A and TaAIP2B were more abundant in wheat PHS susceptible cultivars than that of resistant ones, and decreased gradually following seed development. Expression of TaAIP2A and TaAIP2B in Arabidopsis aip2‐1 mutant lines resulted in earlier flowering, promotion of seed germination,and reduced ABA sensitivity, respectively, somehow mimicking the phenotype of the wild type, with TaAIP2B having a stronger role in these aspects. Furthermore, the expression ofupstream genes ABI1 and ABI2 were upregulated, whereas that of downstream genes ABI3 and ABI5 were downregulated in both TaAIP2A and TaAIP2B complemented lines upon ABA treatment. These results suggested that wheat AIP2s could negatively regulate the ABA signaling pathway and play important roles in seed germination, and thus wheat PHS resistance finally.展开更多
基金the National Key Basic Research Development Program (Grant No. 2000018605 and 1999011708) the Major Research Plan of NSFC (Grant No. 90102012) and the Chinese National Outstanding Youth Fund (Grant No. 40025106)
文摘ABA is one of the 5 phytohormones in higher plants, which is also the most important hormone that regulates higher plants in response to environmental stress, by ABA signal transduction. Understanding ABA signal transduction at the molecular level is crucial to biology and ecology, and rational breeding complied with corresponding eco-environmental changes. Great advancements have taken place over the past 10 years by application of the Arabidopsis experimental system. Many components involved in ABA signal transduction have been isolated and identified and a clear overall picture of gene expression and control for this transduction has become an accepted fact. On the basis of the work in our laboratory, in conjunction with the data available at the moment, the authors have attempted to integrate ABA signal transduction pathways into a common one and give some insights into the relationship between ABA signal transduction and other hormone signal transduction pathways, with an emphasis upon the ABA signal transduction during higher plant seed development. A future challenge in this field is that different experimental systems are applied and various receptors and genes need to be characterized through the utilization of microarray chips.
文摘 A cDNA clone encoding an ABA-responsiveprotein HVA1,was isolated by differentialscreening from barley aleurone layers(Hong etal.).Expression of the HVA1 gene is shownto be developmentally regulated,organ-specif-ic,and ABA-and stress-induced(Hong et
基金supported by the National Natural Science Foundation of China(91117002)
文摘The phytohormone abscisic acid(ABA)plays an important role in plant growth and development,for example in seed dormancy and germination,as well as in plant responses to environmental stresses,such as drought and high salinity.Previous studies have shown that ABA regulates the expression of genes with an ABA-responsive element(ABRE)and their corresponding physiological responses.Bioinformatics analysis identified a GRAM domain-containing gene family that has a multiple ABRE cis-element,which was termed the ABA-responsive protein(ABR)family.To analyze the function of the ABR family,we identified homozygous T-DNA insertion mutants and constructed abr1,2,3 double mutants and triple mutant.The abr1,abr2 and abr3single mutants showed a normal phenotype;however,the germination of seeds of the double mutants and triple mutant were insensitive to ABA,NaCl,mannitol and glucose.ABR1-GFP was distributed as a punctate structure in the cytosol and may be localized in the endomembrane system.The ABR2-GFP and ABR3-GFP proteins localized in the cytoplasm.In addition,ABR1,ABR2 and ABR3 were expressed in various tissues,and could be induced by several abiotic stresses,especially by ABA.The expressions of these genes were significantly suppressed in aba2,abi1 and abi2 null mutants.These results suggested that the ABR family may act downstream of ABI1 and ABI2 in the ABA signal transduction process in plants.
基金partly funded by the China National Basic Research Program supported by the Chinese Ministry of Science and Technology(2009CB118300)
文摘Pre‐harvest sprouting（PHS） seriously affects wheat yield and quality of the grain. ABI3 is a key factor in the activation of seed development and repression of germination in Arabidopsis. An ABI3‐interacting protein（AIP2） could polyubiquitinate ABI3, impair seed dormancy and promote seed germination in Arabidopsis. In this study,two wheat AIP2 genes, TaAIP2A and TaAIP2B, were isolated.Subcellular localization assay and yeast two‐hybrid analysis revealed that TaAIP2A and TaAIP2B may function through interaction with wheat Viviporous‐1（TaVp1）. The transcripts TaAIP2A and TaAIP2B were more abundant in wheat PHS susceptible cultivars than that of resistant ones, and decreased gradually following seed development. Expression of TaAIP2A and TaAIP2B in Arabidopsis aip2‐1 mutant lines resulted in earlier flowering, promotion of seed germination,and reduced ABA sensitivity, respectively, somehow mimicking the phenotype of the wild type, with TaAIP2B having a stronger role in these aspects. Furthermore, the expression ofupstream genes ABI1 and ABI2 were upregulated, whereas that of downstream genes ABI3 and ABI5 were downregulated in both TaAIP2A and TaAIP2B complemented lines upon ABA treatment. These results suggested that wheat AIP2s could negatively regulate the ABA signaling pathway and play important roles in seed germination, and thus wheat PHS resistance finally.
