The G proteinα-subunit,GPA1,is an integral component of several signaling pathways in plants,including response to abiotic stress.However,the molecular mechanism behind these processes remains largely unknown in the ...The G proteinα-subunit,GPA1,is an integral component of several signaling pathways in plants,including response to abiotic stress.However,the molecular mechanism behind these processes remains largely unknown in the cucumber plant(Cucumis sativus L.).In order to further understand the role of CsGPA1 in cucumber under drought stress,changes in plant growth,physiological parameters,and gene expression of CsAQPs were all measured under water stress induced by polyethylene glycol(PEG)using wild type(WT)and CsGPA1-interference(RNAi)cucumber seedlings.Our results demonstrated that the RNAi plants had lower drought tolerance,displaying seriously withered leaves,lower relative growth rate,lower root-shoot ratio,and lower root activity under drought stress compared to WT plants.Physiological studies indicated that the suppression of CsGPA1 weakened drought stress tolerance due to higherwater loss rate in the leaves,higher levels of hydrogen peroxide(H2O2),increased malondialdehyde(MDA)content,lower free proline content,lower soluble sugar content,lower soluble protein content,and decreased antioxidant enzyme activities.qRT-PCR analysis demonstrated that the interference of CsGPA1 up-regulated the expression of most AQP genes(except for CsPIP2;3 in leaves)and down-regulated the expression of CsPIP1;2,CsPIP1;4,CsPIP2;1,and CsPIP2;4 in roots under drought stress when compared to WT plants.Our results demonstrated that CsGPA1 could function as a positive regulator in drought stress response by decreasing the accumulation of reactive oxygen species(ROS),improving permeable potentials,and reducing water loss in cucumber plants.展开更多
L-galactono-1, 4-lactone dehydrogenase(GLDH) is an important enzyme that catalyzes the last step of the ascorbate biosynthetic pathways in plants. A full-length c DNA clone encoding GLDH was isolated from potato(Solan...L-galactono-1, 4-lactone dehydrogenase(GLDH) is an important enzyme that catalyzes the last step of the ascorbate biosynthetic pathways in plants. A full-length c DNA clone encoding GLDH was isolated from potato(Solanum tuberosum L. ‘Favorita') leaf and subcloned into a binary vector, p BI121, to construct sense and antisense recombinant plant expression vectors. The recombinants were introduced into potato via Agrobacterium-mediated transformation, and plants were confirmed as transgenic using PCR and quantitative real-time PCR. Two anti-sense potato lines(G1 and G2) and three sense lines(G3, G4 and G5) were obtained. The GLDH activity of G4 and G5 were increased in vivo. Moreover, the ascorbic acid(As A) and dehydroascorbate(DHA) contents were up-regulated in both leaves and tubers. However, the shoots of G1 were suppressed and its leaves were deformed. Additionally, the As A contents in G1 leaves and tubers decreased by 28.8% and 10.3%, respectively. The GLDH activity in leaves treated with L-galactono-1,4- lactone(L-Gal L) increased in all lines, as did the As A and DHA contents. These results indicate that GLDH activity plays an important role in regulating the As A level as well as the growth and development of potato plants.展开更多
基金This work was supported by the earmarked fund for The National Key Research and Development Program of China(Grant No.2018YFD1000800)National Nature Science Foundation of China(Grant No.32072650)+1 种基金Science and Technology Innovation Program of the Chinese Academy of Agricultural Sciences(Grant No.CAAS-ASTIP-IVFCAAS)the support by the Key Laboratory of Horticultural Crop Biology and Germplasm Innovation,Ministry of Agriculture,China.
文摘The G proteinα-subunit,GPA1,is an integral component of several signaling pathways in plants,including response to abiotic stress.However,the molecular mechanism behind these processes remains largely unknown in the cucumber plant(Cucumis sativus L.).In order to further understand the role of CsGPA1 in cucumber under drought stress,changes in plant growth,physiological parameters,and gene expression of CsAQPs were all measured under water stress induced by polyethylene glycol(PEG)using wild type(WT)and CsGPA1-interference(RNAi)cucumber seedlings.Our results demonstrated that the RNAi plants had lower drought tolerance,displaying seriously withered leaves,lower relative growth rate,lower root-shoot ratio,and lower root activity under drought stress compared to WT plants.Physiological studies indicated that the suppression of CsGPA1 weakened drought stress tolerance due to higherwater loss rate in the leaves,higher levels of hydrogen peroxide(H2O2),increased malondialdehyde(MDA)content,lower free proline content,lower soluble sugar content,lower soluble protein content,and decreased antioxidant enzyme activities.qRT-PCR analysis demonstrated that the interference of CsGPA1 up-regulated the expression of most AQP genes(except for CsPIP2;3 in leaves)and down-regulated the expression of CsPIP1;2,CsPIP1;4,CsPIP2;1,and CsPIP2;4 in roots under drought stress when compared to WT plants.Our results demonstrated that CsGPA1 could function as a positive regulator in drought stress response by decreasing the accumulation of reactive oxygen species(ROS),improving permeable potentials,and reducing water loss in cucumber plants.
基金support provided by the National Natural Science Foundation of China(30771473)the Science and Technology Innovation Program of the Chinese Academy of Agricultural Sciences(CAAS-ASTIP-IVFCAAS)Special Fund for Agroscientific Research in the Public Interest and the Key Laboratory of Horticultural Crop Biology and Germplasm Innovation,Ministry of Agriculture,China
文摘L-galactono-1, 4-lactone dehydrogenase(GLDH) is an important enzyme that catalyzes the last step of the ascorbate biosynthetic pathways in plants. A full-length c DNA clone encoding GLDH was isolated from potato(Solanum tuberosum L. ‘Favorita') leaf and subcloned into a binary vector, p BI121, to construct sense and antisense recombinant plant expression vectors. The recombinants were introduced into potato via Agrobacterium-mediated transformation, and plants were confirmed as transgenic using PCR and quantitative real-time PCR. Two anti-sense potato lines(G1 and G2) and three sense lines(G3, G4 and G5) were obtained. The GLDH activity of G4 and G5 were increased in vivo. Moreover, the ascorbic acid(As A) and dehydroascorbate(DHA) contents were up-regulated in both leaves and tubers. However, the shoots of G1 were suppressed and its leaves were deformed. Additionally, the As A contents in G1 leaves and tubers decreased by 28.8% and 10.3%, respectively. The GLDH activity in leaves treated with L-galactono-1,4- lactone(L-Gal L) increased in all lines, as did the As A and DHA contents. These results indicate that GLDH activity plays an important role in regulating the As A level as well as the growth and development of potato plants.
