Background Mepiquat chloride(MC)is a widely used plant growth regulator in cotton(Gossypium hirsutum L.).It regulates endogenous hormone content and crosstalk to control plant height and promote lateral root(LR)develo...Background Mepiquat chloride(MC)is a widely used plant growth regulator in cotton(Gossypium hirsutum L.).It regulates endogenous hormone content and crosstalk to control plant height and promote lateral root(LR)development.However,the roles of cytokinins(CTKs)in the MC-induced increase in LR number in cotton seedlings remain unclear.Therefore,in this study,whole-genome transcriptome analysis was performed to elucidate the molecular mechanisms,CTK transformation,and CTK signaling pathway response to MC in cotton roots.Results In the present study,MC reduced the contents of the active CTK trans-zeatin(tZ)and N^(6)-isopentenyladenine(iP)but increased the levels of the nucleoside CTK trans-zeatin riboside(tZR)and N^(6)-isopentenyladenine riboside(iPR).RNA-seq data showed that the CTK biosynthesis genes GhIPTs and active CTK catabolism genes GhCKXs were obviously upregulated after MC treatment.The CTK-activating enzyme gene GhLOGs was repressed compared with the control.Furthermore,MC inhibited the expression of GhAHK4 and GhARR2/12,which are involved in the CTK signaling pathway,and activated the IAA-IAA14-ARF7/19 signaling module.Meanwhile,MC increased the expression levels of genes involved in sucrose synthesis,the cell cycle,cell division,and cell wall biosynthesis pathways.Silencing the GhCKX family separately decreased the LR number and active indole-3-acetic acid(IAA)level.The expression levels of GhPIN1,GhARF7,GhARF19,GhLBD16,GhLBD18,GhLBD29,and GhLBD33 were downregulated,but GhARR2/12 and GhIAA14 were upregulated.The total content of active CTKs was noticeably increased.The results of silencing the GhLOGs family were opposite to those of silencing GhCKXs.Silencing GhARR12 could upregulate GhPIN1 expression and increase LR number.In addition,the silenced GhCKXs,GhLOGs,and GhARR12 were less responsive to MCinduced LR growth than the control.Conclusion These results suggested that MC treatment could upregulate CTK-nucleoside biosynthesis and CTK metabolism genes to decrease active CTK levels,promoting crosstalk between CTKs and auxin signaling pathways to enhance LR initiation.展开更多
Background:Soil salinity seriously affects cotton growth,leading to the reduction of yield and fiber quality.Recently,genetic engineering has become an efficient tool to increase abiotic stress tolerance in crops.Resu...Background:Soil salinity seriously affects cotton growth,leading to the reduction of yield and fiber quality.Recently,genetic engineering has become an efficient tool to increase abiotic stress tolerance in crops.Results:In this study,isopentyl transferase(IPT),a key enzyme involved in cytokinin(CTK) biosynthesis from Agrobacterium tumefaciens,was selected to generate transgenic cotton via Agrobacterium-mediated transformation.A senescence-inducible SAG12 promoter from Arabidopsis was fused with the IPT gene.Ectopic-expression of SAG12::IPT significantly promoted seed germination or seedling tolerance to salt stress.Two IPTtransgenic lines,OE3 as a tolerant line during seed germination,and OE8 as a tolerant line at seedling stage,were selected for further physiological analysis.The data showed that ectopic-expression of SAG12::IPT induced the accumulation of CTKs not only in leaves and roots,but also in germinating seeds.Moreover,ectopic-expressing IPT increased the activity of antioxidant enzymes,which was associated with the less reactive oxygen species(ROS) accumulation compared with control plants.Also,ectopic-expression of IPT produced higher K^+/Na^+ratio in cotton shoot and root Conclusion:The senescence-induced CTK accumulation in cotton seeds and seedlings positively regulates salt stress partially by elevating ROS scavenging capability.展开更多
The development of plant branching plays a pivotal role in the morphogenesis of plants. It is affected by the genes and also by the environment. Recent studies of plant branching had made great progresses in the devel...The development of plant branching plays a pivotal role in the morphogenesis of plants. It is affected by the genes and also by the environment. Recent studies of plant branching had made great progresses in the development of the branch control of the physiology, biochemistry, functional genomics, comparative genomics and other aspects. Moreover, we got many mutants associated with the branch development from pea, Arabidopsis, petunia, rice, tomato and corn, such as the formation of axillary meristem-related revoluta （rev）, pinhead, monoculml （mocl）, laterral suppressor （ls）, blind/torosa and other mutants. Preliminary study showed that the formation of meristem development was controlled by regulating hormones and transcription factor interaction network, but the development was both conservative and distinctive in different Mycobacterium species展开更多
基金supported by the National Natural Science Foundation of China(Grant No.31471434)。
文摘Background Mepiquat chloride(MC)is a widely used plant growth regulator in cotton(Gossypium hirsutum L.).It regulates endogenous hormone content and crosstalk to control plant height and promote lateral root(LR)development.However,the roles of cytokinins(CTKs)in the MC-induced increase in LR number in cotton seedlings remain unclear.Therefore,in this study,whole-genome transcriptome analysis was performed to elucidate the molecular mechanisms,CTK transformation,and CTK signaling pathway response to MC in cotton roots.Results In the present study,MC reduced the contents of the active CTK trans-zeatin(tZ)and N^(6)-isopentenyladenine(iP)but increased the levels of the nucleoside CTK trans-zeatin riboside(tZR)and N^(6)-isopentenyladenine riboside(iPR).RNA-seq data showed that the CTK biosynthesis genes GhIPTs and active CTK catabolism genes GhCKXs were obviously upregulated after MC treatment.The CTK-activating enzyme gene GhLOGs was repressed compared with the control.Furthermore,MC inhibited the expression of GhAHK4 and GhARR2/12,which are involved in the CTK signaling pathway,and activated the IAA-IAA14-ARF7/19 signaling module.Meanwhile,MC increased the expression levels of genes involved in sucrose synthesis,the cell cycle,cell division,and cell wall biosynthesis pathways.Silencing the GhCKX family separately decreased the LR number and active indole-3-acetic acid(IAA)level.The expression levels of GhPIN1,GhARF7,GhARF19,GhLBD16,GhLBD18,GhLBD29,and GhLBD33 were downregulated,but GhARR2/12 and GhIAA14 were upregulated.The total content of active CTKs was noticeably increased.The results of silencing the GhLOGs family were opposite to those of silencing GhCKXs.Silencing GhARR12 could upregulate GhPIN1 expression and increase LR number.In addition,the silenced GhCKXs,GhLOGs,and GhARR12 were less responsive to MCinduced LR growth than the control.Conclusion These results suggested that MC treatment could upregulate CTK-nucleoside biosynthesis and CTK metabolism genes to decrease active CTK levels,promoting crosstalk between CTKs and auxin signaling pathways to enhance LR initiation.
基金supported by The Genetically Modified Organisms Breeding Major Projects of China Grant(2016ZX08005-004)
文摘Background:Soil salinity seriously affects cotton growth,leading to the reduction of yield and fiber quality.Recently,genetic engineering has become an efficient tool to increase abiotic stress tolerance in crops.Results:In this study,isopentyl transferase(IPT),a key enzyme involved in cytokinin(CTK) biosynthesis from Agrobacterium tumefaciens,was selected to generate transgenic cotton via Agrobacterium-mediated transformation.A senescence-inducible SAG12 promoter from Arabidopsis was fused with the IPT gene.Ectopic-expression of SAG12::IPT significantly promoted seed germination or seedling tolerance to salt stress.Two IPTtransgenic lines,OE3 as a tolerant line during seed germination,and OE8 as a tolerant line at seedling stage,were selected for further physiological analysis.The data showed that ectopic-expression of SAG12::IPT induced the accumulation of CTKs not only in leaves and roots,but also in germinating seeds.Moreover,ectopic-expressing IPT increased the activity of antioxidant enzymes,which was associated with the less reactive oxygen species(ROS) accumulation compared with control plants.Also,ectopic-expression of IPT produced higher K^+/Na^+ratio in cotton shoot and root Conclusion:The senescence-induced CTK accumulation in cotton seeds and seedlings positively regulates salt stress partially by elevating ROS scavenging capability.
基金Supported by the Natural Science Projects of Heilongjiang Province (2303409)
文摘The development of plant branching plays a pivotal role in the morphogenesis of plants. It is affected by the genes and also by the environment. Recent studies of plant branching had made great progresses in the development of the branch control of the physiology, biochemistry, functional genomics, comparative genomics and other aspects. Moreover, we got many mutants associated with the branch development from pea, Arabidopsis, petunia, rice, tomato and corn, such as the formation of axillary meristem-related revoluta （rev）, pinhead, monoculml （mocl）, laterral suppressor （ls）, blind/torosa and other mutants. Preliminary study showed that the formation of meristem development was controlled by regulating hormones and transcription factor interaction network, but the development was both conservative and distinctive in different Mycobacterium species
