为了了解小麦ABA受体基因TaPYL9(Pyrabactin resistance like 9)在非生物胁迫下的功能,通过同源克隆法获得小麦TaPYL9基因,对其进行生物信息学分析,并采用实时荧光定量PCR(qRT-PCR)技术检测该基因在ABA、NaCl和PEG处理下的表达情况。结...为了了解小麦ABA受体基因TaPYL9(Pyrabactin resistance like 9)在非生物胁迫下的功能,通过同源克隆法获得小麦TaPYL9基因,对其进行生物信息学分析,并采用实时荧光定量PCR(qRT-PCR)技术检测该基因在ABA、NaCl和PEG处理下的表达情况。结果表明,TaPYL9 cDNA全长1173 bp,开放阅读框618 bp,编码1个包含205个氨基酸残基的不稳定的亲水蛋白,该蛋白以α-螺旋为主,含有1个由2个α-螺旋和7个β-折叠组成的PYL螺旋手柄结构;TaPYL9蛋白与山羊草AsPYL9-like蛋白亲缘关系最近,与拟南芥AtPYL9蛋白属于同一亚族;TaPYL9蛋白和AsPYL9-like蛋白保守基序相同,与拟南芥13个PYL中的AtPYL9蛋白的保守基序相似性最高;TaPYL9在ABA、NaCl和PEG处理下总体上表达量上升。综上,TaPYL9为小麦ABA受体蛋白,对ABA敏感,可能参与小麦高盐和干旱胁迫应答的调控。展开更多
Unveiling the signal transduction of phytohormone abscisic acid （ABA） and its regulatory mechanisms is critical for developing the strategies toward improving plant responses to stressful environments. ABA signaling...Unveiling the signal transduction of phytohormone abscisic acid （ABA） and its regulatory mechanisms is critical for developing the strategies toward improving plant responses to stressful environments. ABA signaling is perceived and mediated by multiple PYR/PYL receptors, whose post-translational modifications, especially phosphorylation, remain largely unknown. In this study, we demonstrate thatArabidopsis ELl-like （AEL） protein, a casein kinase that regulates various physiological processes, phosphorylate PYR/PYLs to promote their ubiquitination and degradation, resulting in suppressed ABA responses. Arabidopsis ael triple mutants display hypersensitive responses to ABA treatment, which is consistent with the suppressed degradation of PYR/PYL proteins. PYR/PYLs are phosphorylated in vivo and mutation of the conserved AEL phosphorylation sites results in reduced phosphorylation, ubiquitination, and degradation of PYR/PYLs, and hence enhanced ABA responses. Taken together, these results demonstrate that AEL-mediated phosphorylation plays crucial roles in regulating the stability and function of PYR/ PYLs, providing significant insights into the post-translational regulation of PYR/PYL receptors and ABA signaling.展开更多
The phytohormone abscisic acid （ABA） regulates many key processes in plants, such as seed germina- tion, seedling growth, and abiotic stress tolerance. In recent years, a minimal set of core components of a major AB...The phytohormone abscisic acid （ABA） regulates many key processes in plants, such as seed germina- tion, seedling growth, and abiotic stress tolerance. In recent years, a minimal set of core components of a major ABA signaling pathway has been discovered. These components include a RCAR/PYR/PYL family of ABA receptors, a group of PP2C phosphatases, and three SnRK2 kinases. However, how the interactions between the receptors and their targets are regulated by other proteins remains largely unknown. In a companion paper published in this issue, we showed that ROP11, a member of the plant- specific Rho-like small GTPase family, negatively regulates multiple ABA responses in Arabidopsis. The current work demonstrated that the constitutively active ROP11 （CA-ROP11） can modulate the RCAR1/PYL9-mediated ABA signaling pathway based on reconstitution assays in Arabidopsis thaliana protoplasts. Furthermore, using luciferase complementation imaging, yeast two-hybrid assays, co- immunoprecipitation assays in Nicotiana benthamiana and bimolecular fluorescence complementation assays, we demonstrated that CA-ROP11 directly interacts with ABI1, a signaling component downstream of RCAR1/PYL9. Finally, we provided biochemical evidence that CA-ROP11 protects ABI1 phosphatase activity from inhibition by RCAR1/PYL9 and thus negatively regulates ABA signaling in plant cells. A model of how ROP11 acts to negatively regulate ABA signaling is presented.展开更多
As abscisic acid(ABA)receptor,the pyrabactin resistance 1-like(PYR/PYL)protein(named PYL for simplicity)plays an important part to unveil the signal transduction of ABA and its regulatory mechanisms.Glycyrrhiza uralen...As abscisic acid(ABA)receptor,the pyrabactin resistance 1-like(PYR/PYL)protein(named PYL for simplicity)plays an important part to unveil the signal transduction of ABA and its regulatory mechanisms.Glycyrrhiza uralensis,a drought-tolerant medicinal plant,is a good model for the mechanism analysis of ABA response and active compound biosynthesis.However,knowledge about PYL family in G.uralensis remains largely unknown.Here,10 PYLs were identified in G.uralensis genome.Characterization analysis indicated that PYLs in G.uralensis(Gu PYLs)are relatively conserved.Phylogenetic analysis showed that Gu PYL1-3 belongs to subfamily I,Gu PYL4-6 and Gu PYL10 belong to subfamily II and Gu PYL7-9 belongs to subfamily III.In addition,transcriptome data presented various expression levels of Gu PYLs under different exogenous ABA stresses.The expression pattern of Gu PYLs was verified by Quantitative real-time polymerase chain reaction(q RT-PCR).The study proved that Gu PYL4,Gu PYL5,Gu PYL8 and Gu PYL9 genes are significantly up-regulated by ABA stress and the response process is dynamic.This study paves the way for elucidating the regulation mechanism of ABA signal to secondary metabolites and improving the cultivation and quality of G.uralensis using agricultural strategies.展开更多
植物激素脱落酸(ABA)参与从种子萌发到植物开花、结果和衰老等多个生长发育过程。研究ABA细胞信号转导的分子机制对进一步阐明其功能具有重要的意义。通过介绍FCA(Flowering Control Locus A)、Mg离子螯合酶H亚基(ABAR/CHLH)、G蛋白偶...植物激素脱落酸(ABA)参与从种子萌发到植物开花、结果和衰老等多个生长发育过程。研究ABA细胞信号转导的分子机制对进一步阐明其功能具有重要的意义。通过介绍FCA(Flowering Control Locus A)、Mg离子螯合酶H亚基(ABAR/CHLH)、G蛋白偶联受体(GCR2)、GTG1/GTG2(GPCR-type G-Proteins1/2)和PYR1/PYL/RCAR在ABA信号传导途径中的作用模式,阐述了其能够接受ABA信号并激活相关下游组分,从而完成其生理功能。展开更多
Seed germination and seedling establishment are important for the reproductive success of plants,but seeds and seedlings typically encounter constantly changing environmental conditions.By inhibiting seed germination ...Seed germination and seedling establishment are important for the reproductive success of plants,but seeds and seedlings typically encounter constantly changing environmental conditions.By inhibiting seed germination and post-germinative growth through the PYR1/PYL/RCAR ABA receptors and PP2C co-receptors,the phytohormone abscisic acid(ABA)prevents premature germination and seedling growth under unfavorable conditions.However,little is known about how the ABA-mediated inhibition of seed germination and seedling establishment is thwarted.Here,we report that ABA Signaling Terminator(ABT),a WD40 protein,efficiently switches off ABA signaling and is critical for seed germination and seedling establishment.ABT is induced by ABA in a PYR1/PYL/RCAR-PP2C-dependent manner.Overexpression of ABT promotes seed germination and seedling greening in the presence of ABA,whereas knockout of ABT has the opposite effect.We found that ABT interacts with the PYR1/PYL/RCAR and PP2C proteins,interferes with the interaction between PYR1/PYL4 and ABI1/ABI2,and hampers the inhibition of ABI1/ABI2 by ABA-bound PYR1/PYL4,thereby terminating ABA signaling.Taken together,our results reveal a core mechanism of ABA signaling termination that is critical for seed germination and seedling establishment in Arabidopsis.展开更多
文摘Unveiling the signal transduction of phytohormone abscisic acid （ABA） and its regulatory mechanisms is critical for developing the strategies toward improving plant responses to stressful environments. ABA signaling is perceived and mediated by multiple PYR/PYL receptors, whose post-translational modifications, especially phosphorylation, remain largely unknown. In this study, we demonstrate thatArabidopsis ELl-like （AEL） protein, a casein kinase that regulates various physiological processes, phosphorylate PYR/PYLs to promote their ubiquitination and degradation, resulting in suppressed ABA responses. Arabidopsis ael triple mutants display hypersensitive responses to ABA treatment, which is consistent with the suppressed degradation of PYR/PYL proteins. PYR/PYLs are phosphorylated in vivo and mutation of the conserved AEL phosphorylation sites results in reduced phosphorylation, ubiquitination, and degradation of PYR/PYLs, and hence enhanced ABA responses. Taken together, these results demonstrate that AEL-mediated phosphorylation plays crucial roles in regulating the stability and function of PYR/ PYLs, providing significant insights into the post-translational regulation of PYR/PYL receptors and ABA signaling.
基金supported by the 973National Basic Research Program of the Ministry of Science and Technology of China(2009CB119100)the National Natural Science Foundation of China(90717121)
文摘The phytohormone abscisic acid （ABA） regulates many key processes in plants, such as seed germina- tion, seedling growth, and abiotic stress tolerance. In recent years, a minimal set of core components of a major ABA signaling pathway has been discovered. These components include a RCAR/PYR/PYL family of ABA receptors, a group of PP2C phosphatases, and three SnRK2 kinases. However, how the interactions between the receptors and their targets are regulated by other proteins remains largely unknown. In a companion paper published in this issue, we showed that ROP11, a member of the plant- specific Rho-like small GTPase family, negatively regulates multiple ABA responses in Arabidopsis. The current work demonstrated that the constitutively active ROP11 （CA-ROP11） can modulate the RCAR1/PYL9-mediated ABA signaling pathway based on reconstitution assays in Arabidopsis thaliana protoplasts. Furthermore, using luciferase complementation imaging, yeast two-hybrid assays, co- immunoprecipitation assays in Nicotiana benthamiana and bimolecular fluorescence complementation assays, we demonstrated that CA-ROP11 directly interacts with ABI1, a signaling component downstream of RCAR1/PYL9. Finally, we provided biochemical evidence that CA-ROP11 protects ABI1 phosphatase activity from inhibition by RCAR1/PYL9 and thus negatively regulates ABA signaling in plant cells. A model of how ROP11 acts to negatively regulate ABA signaling is presented.
基金supported by the National Science and Technology Major Project for“Significant New Drugs Development”(No.2019ZX09201005-006-003)the ChinesAcademy of Medical Sciences(CAMS)Innovation Fund for Medical Sciences(CIFMS)(No.2016-I2M-3-016)。
文摘As abscisic acid(ABA)receptor,the pyrabactin resistance 1-like(PYR/PYL)protein(named PYL for simplicity)plays an important part to unveil the signal transduction of ABA and its regulatory mechanisms.Glycyrrhiza uralensis,a drought-tolerant medicinal plant,is a good model for the mechanism analysis of ABA response and active compound biosynthesis.However,knowledge about PYL family in G.uralensis remains largely unknown.Here,10 PYLs were identified in G.uralensis genome.Characterization analysis indicated that PYLs in G.uralensis(Gu PYLs)are relatively conserved.Phylogenetic analysis showed that Gu PYL1-3 belongs to subfamily I,Gu PYL4-6 and Gu PYL10 belong to subfamily II and Gu PYL7-9 belongs to subfamily III.In addition,transcriptome data presented various expression levels of Gu PYLs under different exogenous ABA stresses.The expression pattern of Gu PYLs was verified by Quantitative real-time polymerase chain reaction(q RT-PCR).The study proved that Gu PYL4,Gu PYL5,Gu PYL8 and Gu PYL9 genes are significantly up-regulated by ABA stress and the response process is dynamic.This study paves the way for elucidating the regulation mechanism of ABA signal to secondary metabolites and improving the cultivation and quality of G.uralensis using agricultural strategies.
文摘植物激素脱落酸(ABA)参与从种子萌发到植物开花、结果和衰老等多个生长发育过程。研究ABA细胞信号转导的分子机制对进一步阐明其功能具有重要的意义。通过介绍FCA(Flowering Control Locus A)、Mg离子螯合酶H亚基(ABAR/CHLH)、G蛋白偶联受体(GCR2)、GTG1/GTG2(GPCR-type G-Proteins1/2)和PYR1/PYL/RCAR在ABA信号传导途径中的作用模式,阐述了其能够接受ABA信号并激活相关下游组分,从而完成其生理功能。
基金supported by the National Key Research and Development Program of China(2016YFA0500503)the Fundamental Research Funds for the Central Universities(2662018PY075)+1 种基金the National Natural Science Foundation of China(31730066,91540112)the Huazhong Agricultural University's Scientific and Technological Self-innovation Foundation(2015RC014).
文摘Seed germination and seedling establishment are important for the reproductive success of plants,but seeds and seedlings typically encounter constantly changing environmental conditions.By inhibiting seed germination and post-germinative growth through the PYR1/PYL/RCAR ABA receptors and PP2C co-receptors,the phytohormone abscisic acid(ABA)prevents premature germination and seedling growth under unfavorable conditions.However,little is known about how the ABA-mediated inhibition of seed germination and seedling establishment is thwarted.Here,we report that ABA Signaling Terminator(ABT),a WD40 protein,efficiently switches off ABA signaling and is critical for seed germination and seedling establishment.ABT is induced by ABA in a PYR1/PYL/RCAR-PP2C-dependent manner.Overexpression of ABT promotes seed germination and seedling greening in the presence of ABA,whereas knockout of ABT has the opposite effect.We found that ABT interacts with the PYR1/PYL/RCAR and PP2C proteins,interferes with the interaction between PYR1/PYL4 and ABI1/ABI2,and hampers the inhibition of ABI1/ABI2 by ABA-bound PYR1/PYL4,thereby terminating ABA signaling.Taken together,our results reveal a core mechanism of ABA signaling termination that is critical for seed germination and seedling establishment in Arabidopsis.
