植物激素脱落酸（abscisic acid,ABA）在植物生长、发育及环境胁迫中起着重要的作用。本研究发现拟南芥PKSes（SOS2-like protein kinases）蛋白激酶家族成员PKS5（SOS2-like protein kinase 5）参与植物ABA响应。PKS5功能获得性点突变...植物激素脱落酸（abscisic acid,ABA）在植物生长、发育及环境胁迫中起着重要的作用。本研究发现拟南芥PKSes（SOS2-like protein kinases）蛋白激酶家族成员PKS5（SOS2-like protein kinase 5）参与植物ABA响应。PKS5功能获得性点突变体pks5-3与pks5-4表现出对ABA的敏感表型。在外源ABA处理下,pks5-3与pks5-4种子萌发率降低,幼苗生长矮小、黄化。体外磷酸化测试显示,PKS5特异磷酸化ABA响应元件ABI5（ABA-insensitive 5）N末端多肽（1~211 aa）。q RT-PCR分析表明pks5-3与pks5-4突变体中ABI5下游ABA响应基因RAB18（RESPONSIVE TO ABA18）与EM6（LATE EMBRYOGENESIS ABUNDANT 6）表达均发生改变。这些研究结果表明,拟南芥PKS5通过磷酸化ABI5的N末端参与植物ABA响应过程。展开更多
Seed germination or dormancy status is strictly controlled by endogenous phytohormone and exogenous environment signals.Abscisic acid(ABA)is the important phytohormone to suppress seed germination.Ambient high tempera...Seed germination or dormancy status is strictly controlled by endogenous phytohormone and exogenous environment signals.Abscisic acid(ABA)is the important phytohormone to suppress seed germination.Ambient high temperature(HT)also suppressed seed germination,or called as secondary seed dormancy,through upregulating ABI5,the essential component of ABA signal pathway.Previous result shows that appropriate nitric oxide(NO)breaks seed dormancy through triggering S-nitrosoglutathion reductase(GSNOR1)-dependent S-nitrosylation modification of ABI5 protein,subsequently inducing the degradation of ABI5.Here we found that HT induced the degradation of GSNOR1 protein and reduced its activity,thus accumulated more reactive nitrogen species(RNS)to damage seeds viability.Furthermore,HT increased the S-nitrosylation modification of GSNOR1 protein,and triggered the degradation of GSNOR1,therefore stabilizing ABI5 to suppress seed germination.Consistently,the ABI5 protein abundance was lower in the transgenic line overexpressing GSNOR1,but higher in the gsnor mutant after HT stress.Genetic analysis showed that GSNOR1 affected seeds germination through ABI5 under HT.Taken together,our data reveals a new mechanism by which HT triggers the degradation of GSNOR1,and thus stabilizing ABI5 to suppress seed germination,such mechanism provides the possibility to enhance seed germination tolerance to HT through genetic modification of GNSOR1.展开更多
Nitrate is a major nitrogen resource for plant growth and development and acts as both a crucial nutrient and a signaling molecule for plants;hence,understanding nitrate signaling is important for crop production.Absc...Nitrate is a major nitrogen resource for plant growth and development and acts as both a crucial nutrient and a signaling molecule for plants;hence,understanding nitrate signaling is important for crop production.Abscisic acid(ABA)has been demonstrated to be involved in nitrate signaling,but the underlying mechanism is largely unknown in apple.In this study,we found that exogenous ABA inhibited the transport of nitrate from roots to shoots in apple,and the transcription of the nitrate transporter MdNRT1.5/MdNPF7.3 was noticeably reduced at the transcriptional level by ABA,which inhibited the transport of nitrate from roots to shoots.Then,it was found that the ABA-responsive transcription factor MdABI5 bound directly to the ABRE recognition site of the MdNRT1.5 promoter and suppressed its expression.Overexpression of MdABI5 inhibited ABA-mediated transport of nitrate from roots to shoots.Overall,these results demonstrate that MdABI5 regulates the transport of nitrate from roots to shoots partially by mediating the expression of MdNRT1.5,illuminating the molecular mechanism by which ABA regulates nitrate transport in apple.展开更多
Seed viability is an essential feature for genetic resource conservation as well as sustainable crop production.Long-term storage induces seed viability deterioration or seed aging,accompanied by the accumulation of t...Seed viability is an essential feature for genetic resource conservation as well as sustainable crop production.Long-term storage induces seed viability deterioration or seed aging,accompanied by the accumulation of toxic reactive oxygen species(ROS)to suppress seed germination.Controlled deterioration treatment(CDT)is a gen-eral approach for mimicking seed aging.The transcription factor ANAC089 was previously reported to modulate seed primary germination.In this study,we evaluated the ability of ANAC089 to control seed viability during aging.Compared with that in the wild-type line,the mutation of ANAC089 significantly increased H_(2)O_(2),thereby reducing seed viability after CDT,while the overexpression of ANAC089 reduced H_(2)O_(2) and improved seed long-evity,indicating a critical role for ANAC089 in maintaining seed viability through H_(2)O_(2) signaling.A series of stu-dies have shown that ANAC089 targets and negatively regulates the level of ABI5,an important transmitter of abscisic acid(ABA)signals,to affect seed viability after CDT.Furthermore,ABI5 negatively regulated the expres-sion of VTC2,which is involved in the biosynthesis of the antioxidant ascorbic acid and H_(2)O_(2) scavenging.As a result,ANAC089 attenuates the generation of H_(2)O_(2),thereby enhancing seed viability through the ABI5-VTC2 module during the seed aging process.Taken together,our results reveal a novel mechanism by which ANAC089 enhances seed viability by coordinating ABI5 and VTC2 expression,ultimately preventing the overac-cumulation of H_(2)O_(2),which would have led to reduced seed viability.展开更多
Seed germination is a crucial checkpoint for plant survival under unfavorable environmental conditions. Ab- scisic acid （ABA） signaling plays a vital role in integrating environmental information to regulate seed ge...Seed germination is a crucial checkpoint for plant survival under unfavorable environmental conditions. Ab- scisic acid （ABA） signaling plays a vital role in integrating environmental information to regulate seed germination. It has been well known that MCMI/AGAMOUS/DEFICIENS/SRF （MADS）-box transcription factors are key regulators of seed and flower development in Arabidopsis. However, little is known about their functions in seed germination. Here we report that MADS-box transcription factor AGL21 is a negative regulator of seed germination and post-germination growth by controlling the expression of ABA-INSENSITIVE 5 （ABIb＇） in Arabidopsis. The AGL21-overexpressing plants were hypersensitive to ABA, salt, and osmotic stresses during seed germination and early post-germination growth, whereas ag121 mutants were less sensitive. We found that AGL21 positively regulated ABI5 expression in seeds. Consistently, genetic analyses showed that AGL21 is epistatic to ABI5 in controlling seed germination. Chromatin immunoprecipitation assays further demonstrated that AGL21 could directly bind to the ABI5 promoter in plant cells. Moreover, we found that AGL21 responded to multiple environmental stresses and plant hormones during seed germination. Taken together, our results suggest that AGL21 acts as a surveillance integrator that incorporates environmental cues and endogenous hormonal signals into ABA signaling to regulate seed germination and early post-germination growth.展开更多
Under conditions of aluminum(Al) toxicity,which severely inhibits root growth in acidic soils, plants rapidly alter their gene expression to optimize physiological fitness for survival. Abscisic acid(ABA) has been sug...Under conditions of aluminum(Al) toxicity,which severely inhibits root growth in acidic soils, plants rapidly alter their gene expression to optimize physiological fitness for survival. Abscisic acid(ABA) has been suggested as a mediator between Al stress and gene expression, but the underlying mechanisms remain largely unknown. Here,we investigated ABA-mediated Al-stress responses, using integrated physiological and molecular biology approaches.We demonstrate that Al stress caused ABA accumulation in the root apex of rice bean(Vigna umbellata [Thunb.] Ohwi &Ohashi), which positively regulated Al tolerance. However,this was not associated with known Al-tolerance mechanisms. Transcriptomic analysis revealed that nearly one-third of the responsive genes were shared between the Al-stress and ABA treatments. We further identified a transcription factor, ABI5, as being positively involved in Al tolerance. Arabidopsis abi5 mutants displayed increased sensitivity to Al, which was not related to the regulation of AtALMT1 and AtMATE expression. Functional categorization of ABI5-mediated genes revealed the importance of cell wall modification and osmoregulation in Al tolerance, a finding supported by osmotic stress treatment on Al tolerance. Our results suggest that ABA signal transduction pathways provide an additional layer of regulatory control over Al tolerance in plants.展开更多
文摘植物激素脱落酸（abscisic acid,ABA）在植物生长、发育及环境胁迫中起着重要的作用。本研究发现拟南芥PKSes（SOS2-like protein kinases）蛋白激酶家族成员PKS5（SOS2-like protein kinase 5）参与植物ABA响应。PKS5功能获得性点突变体pks5-3与pks5-4表现出对ABA的敏感表型。在外源ABA处理下,pks5-3与pks5-4种子萌发率降低,幼苗生长矮小、黄化。体外磷酸化测试显示,PKS5特异磷酸化ABA响应元件ABI5（ABA-insensitive 5）N末端多肽（1~211 aa）。q RT-PCR分析表明pks5-3与pks5-4突变体中ABI5下游ABA响应基因RAB18（RESPONSIVE TO ABA18）与EM6（LATE EMBRYOGENESIS ABUNDANT 6）表达均发生改变。这些研究结果表明,拟南芥PKS5通过磷酸化ABI5的N末端参与植物ABA响应过程。
基金funded by the National Natural Science Foundation of China(Grants No.31970289).
文摘Seed germination or dormancy status is strictly controlled by endogenous phytohormone and exogenous environment signals.Abscisic acid(ABA)is the important phytohormone to suppress seed germination.Ambient high temperature(HT)also suppressed seed germination,or called as secondary seed dormancy,through upregulating ABI5,the essential component of ABA signal pathway.Previous result shows that appropriate nitric oxide(NO)breaks seed dormancy through triggering S-nitrosoglutathion reductase(GSNOR1)-dependent S-nitrosylation modification of ABI5 protein,subsequently inducing the degradation of ABI5.Here we found that HT induced the degradation of GSNOR1 protein and reduced its activity,thus accumulated more reactive nitrogen species(RNS)to damage seeds viability.Furthermore,HT increased the S-nitrosylation modification of GSNOR1 protein,and triggered the degradation of GSNOR1,therefore stabilizing ABI5 to suppress seed germination.Consistently,the ABI5 protein abundance was lower in the transgenic line overexpressing GSNOR1,but higher in the gsnor mutant after HT stress.Genetic analysis showed that GSNOR1 affected seeds germination through ABI5 under HT.Taken together,our data reveals a new mechanism by which HT triggers the degradation of GSNOR1,and thus stabilizing ABI5 to suppress seed germination,such mechanism provides the possibility to enhance seed germination tolerance to HT through genetic modification of GNSOR1.
基金This work was supported by grants from the National Key R&D Program of China(2018YFD1000100)National Natural Science Foundation of China(31772288 and 31972378)+1 种基金China Agriculture Research System of MOF and MARA(CARS-27)the Agricultural Variety Improvement Project of Shandong Province(2019LZGC007).
文摘Nitrate is a major nitrogen resource for plant growth and development and acts as both a crucial nutrient and a signaling molecule for plants;hence,understanding nitrate signaling is important for crop production.Abscisic acid(ABA)has been demonstrated to be involved in nitrate signaling,but the underlying mechanism is largely unknown in apple.In this study,we found that exogenous ABA inhibited the transport of nitrate from roots to shoots in apple,and the transcription of the nitrate transporter MdNRT1.5/MdNPF7.3 was noticeably reduced at the transcriptional level by ABA,which inhibited the transport of nitrate from roots to shoots.Then,it was found that the ABA-responsive transcription factor MdABI5 bound directly to the ABRE recognition site of the MdNRT1.5 promoter and suppressed its expression.Overexpression of MdABI5 inhibited ABA-mediated transport of nitrate from roots to shoots.Overall,these results demonstrate that MdABI5 regulates the transport of nitrate from roots to shoots partially by mediating the expression of MdNRT1.5,illuminating the molecular mechanism by which ABA regulates nitrate transport in apple.
基金supported by the National Natural Science Foundation of China(31970289 to X.H.and 32170562 to P.L.).
文摘Seed viability is an essential feature for genetic resource conservation as well as sustainable crop production.Long-term storage induces seed viability deterioration or seed aging,accompanied by the accumulation of toxic reactive oxygen species(ROS)to suppress seed germination.Controlled deterioration treatment(CDT)is a gen-eral approach for mimicking seed aging.The transcription factor ANAC089 was previously reported to modulate seed primary germination.In this study,we evaluated the ability of ANAC089 to control seed viability during aging.Compared with that in the wild-type line,the mutation of ANAC089 significantly increased H_(2)O_(2),thereby reducing seed viability after CDT,while the overexpression of ANAC089 reduced H_(2)O_(2) and improved seed long-evity,indicating a critical role for ANAC089 in maintaining seed viability through H_(2)O_(2) signaling.A series of stu-dies have shown that ANAC089 targets and negatively regulates the level of ABI5,an important transmitter of abscisic acid(ABA)signals,to affect seed viability after CDT.Furthermore,ABI5 negatively regulated the expres-sion of VTC2,which is involved in the biosynthesis of the antioxidant ascorbic acid and H_(2)O_(2) scavenging.As a result,ANAC089 attenuates the generation of H_(2)O_(2),thereby enhancing seed viability through the ABI5-VTC2 module during the seed aging process.Taken together,our results reveal a novel mechanism by which ANAC089 enhances seed viability by coordinating ABI5 and VTC2 expression,ultimately preventing the overac-cumulation of H_(2)O_(2),which would have led to reduced seed viability.
基金This work was supported by the China National Natural Science Funds for Distinguished Young Scholar （grant no. 31500231 to L.-H.Yo）, China Postdoctoral Science Foundation, No.9 Special Fund （grant no. 2016T90577 to L.-H.Y.）, and Chinese Academy of Sciences （grant no. KSCX3-EW-N- 07 to C.-B.X.）.
文摘Seed germination is a crucial checkpoint for plant survival under unfavorable environmental conditions. Ab- scisic acid （ABA） signaling plays a vital role in integrating environmental information to regulate seed germination. It has been well known that MCMI/AGAMOUS/DEFICIENS/SRF （MADS）-box transcription factors are key regulators of seed and flower development in Arabidopsis. However, little is known about their functions in seed germination. Here we report that MADS-box transcription factor AGL21 is a negative regulator of seed germination and post-germination growth by controlling the expression of ABA-INSENSITIVE 5 （ABIb＇） in Arabidopsis. The AGL21-overexpressing plants were hypersensitive to ABA, salt, and osmotic stresses during seed germination and early post-germination growth, whereas ag121 mutants were less sensitive. We found that AGL21 positively regulated ABI5 expression in seeds. Consistently, genetic analyses showed that AGL21 is epistatic to ABI5 in controlling seed germination. Chromatin immunoprecipitation assays further demonstrated that AGL21 could directly bind to the ABI5 promoter in plant cells. Moreover, we found that AGL21 responded to multiple environmental stresses and plant hormones during seed germination. Taken together, our results suggest that AGL21 acts as a surveillance integrator that incorporates environmental cues and endogenous hormonal signals into ABA signaling to regulate seed germination and early post-germination growth.
基金supported by the National Natural Science Foundation of China (31501827, 31222049, 31071849, and 31572193)National Basic Research Program of China (973 Program, 2014CB441002)+1 种基金the Open Foundation for State Key Laboratory of Plant Physiology and Biochemistrythe Innovation Team for Farmland Non-pollution Production of Yunnan Province (2017HC015)
文摘Under conditions of aluminum(Al) toxicity,which severely inhibits root growth in acidic soils, plants rapidly alter their gene expression to optimize physiological fitness for survival. Abscisic acid(ABA) has been suggested as a mediator between Al stress and gene expression, but the underlying mechanisms remain largely unknown. Here,we investigated ABA-mediated Al-stress responses, using integrated physiological and molecular biology approaches.We demonstrate that Al stress caused ABA accumulation in the root apex of rice bean(Vigna umbellata [Thunb.] Ohwi &Ohashi), which positively regulated Al tolerance. However,this was not associated with known Al-tolerance mechanisms. Transcriptomic analysis revealed that nearly one-third of the responsive genes were shared between the Al-stress and ABA treatments. We further identified a transcription factor, ABI5, as being positively involved in Al tolerance. Arabidopsis abi5 mutants displayed increased sensitivity to Al, which was not related to the regulation of AtALMT1 and AtMATE expression. Functional categorization of ABI5-mediated genes revealed the importance of cell wall modification and osmoregulation in Al tolerance, a finding supported by osmotic stress treatment on Al tolerance. Our results suggest that ABA signal transduction pathways provide an additional layer of regulatory control over Al tolerance in plants.
