Nitrate is an important nitrogen source and signaling molecule that regulates plant growth and development.Although several components of the nitrate signaling pathway have been identified,the detailed mechanisms are ...Nitrate is an important nitrogen source and signaling molecule that regulates plant growth and development.Although several components of the nitrate signaling pathway have been identified,the detailed mechanisms are still unclear.Our previous results showed that OsMADS25 can regulate root development in response to nitrate signals,but the mechanism is still unknown.Here,we try to answer two key questions:how does OsMADS25 move from the cytoplasm to the nucleus,and what are the direct target genes activated by OsMADS25 to regulate root growth after it moves to the nucleus in response to nitrate?Our results demonstrated that OsMADS25 moves from the cytoplasm to the nucleus in the presence of nitrate in an OsNAR2.1-dependentmanner.Chromatin immunoprecipitation sequencing,chromatin immunoprecipitation qPCR,yeast one-hybrid,and luciferase experiments showed that OsMADS25 directly activates the expression of OsMADS27 and OsARF7,which are reported to be associated with root growth.Finally,OsMADS25-RNAi lines,the Osnar2.1 mutant,and OsMADS25-RNAi Osnar2.1 lines exhibited significantly reduced root growth compared with the wild type in response to nitrate supply,and expression of OsMADS27 and OsARF7 was significantly suppressed in these lines.Collectively,these results reveal a new mechanismby which OsMADS25 interacts with OsNAR2.1.This interaction is required for nuclear accumulation of OsMADS25,which promotes OsMADS27 and OsARF7 expression and root growth in a nitratedependent manner.展开更多
Salt stress is a major constraint on plant growth and yield.Nitrogen(N)fertilizers are known to alleviate salt stress.However,the underlying molecular mechanisms remain unclear.Here,we show that nitratedependent salt ...Salt stress is a major constraint on plant growth and yield.Nitrogen(N)fertilizers are known to alleviate salt stress.However,the underlying molecular mechanisms remain unclear.Here,we show that nitratedependent salt tolerance is mediated by OsMADS27 in rice.The expression of OsMADS27 is specifically induced by nitrate.The salt-inducible expression of OsMADS27 is also nitrate dependent.OsMADS27 knockout mutants are more sensitive to salt stress than the wild type,whereas OsMADS27 overexpression lines are more tolerant.Transcriptomic analyses revealed that OsMADS27 upregulates the expression of a number of known stress-responsive genes as well as those involved in ion homeostasis and antioxidation.We demonstrate that OsMADS27 directly binds to the promoters of OsHKT1.1 and OsSPL7 to regulate their expression.Notably,OsMADS27-mediated salt tolerance is nitrate dependent and positively correlated with nitrate concentration.Our results reveal the role of nitrate-responsive OsMADS27 and its downstream target genes in salt tolerance,providing a molecular mechanism for the enhancement of salt tolerance by nitrogen fertilizers in rice.OsMADS27 overexpression increased grain yield under salt stress in the presence of sufficient nitrate,suggestingthatOsMADS27 is a promising candidate for the improvementof salt tolerance inrice.展开更多
基金funded by the National Key Research and Development Program of China(2021YFF1000400)the Zhejiang Provincial Natural Science Foundation of China(grant no.LZ22C130002)the National Natural Science Foundation of China(grant no.U2202204).
文摘Nitrate is an important nitrogen source and signaling molecule that regulates plant growth and development.Although several components of the nitrate signaling pathway have been identified,the detailed mechanisms are still unclear.Our previous results showed that OsMADS25 can regulate root development in response to nitrate signals,but the mechanism is still unknown.Here,we try to answer two key questions:how does OsMADS25 move from the cytoplasm to the nucleus,and what are the direct target genes activated by OsMADS25 to regulate root growth after it moves to the nucleus in response to nitrate?Our results demonstrated that OsMADS25 moves from the cytoplasm to the nucleus in the presence of nitrate in an OsNAR2.1-dependentmanner.Chromatin immunoprecipitation sequencing,chromatin immunoprecipitation qPCR,yeast one-hybrid,and luciferase experiments showed that OsMADS25 directly activates the expression of OsMADS27 and OsARF7,which are reported to be associated with root growth.Finally,OsMADS25-RNAi lines,the Osnar2.1 mutant,and OsMADS25-RNAi Osnar2.1 lines exhibited significantly reduced root growth compared with the wild type in response to nitrate supply,and expression of OsMADS27 and OsARF7 was significantly suppressed in these lines.Collectively,these results reveal a new mechanismby which OsMADS25 interacts with OsNAR2.1.This interaction is required for nuclear accumulation of OsMADS25,which promotes OsMADS27 and OsARF7 expression and root growth in a nitratedependent manner.
基金The Strategic Priority Research Program of the Chinese Academy of Sciences(grant no.XDA24010303 to C.B.X.).
文摘Salt stress is a major constraint on plant growth and yield.Nitrogen(N)fertilizers are known to alleviate salt stress.However,the underlying molecular mechanisms remain unclear.Here,we show that nitratedependent salt tolerance is mediated by OsMADS27 in rice.The expression of OsMADS27 is specifically induced by nitrate.The salt-inducible expression of OsMADS27 is also nitrate dependent.OsMADS27 knockout mutants are more sensitive to salt stress than the wild type,whereas OsMADS27 overexpression lines are more tolerant.Transcriptomic analyses revealed that OsMADS27 upregulates the expression of a number of known stress-responsive genes as well as those involved in ion homeostasis and antioxidation.We demonstrate that OsMADS27 directly binds to the promoters of OsHKT1.1 and OsSPL7 to regulate their expression.Notably,OsMADS27-mediated salt tolerance is nitrate dependent and positively correlated with nitrate concentration.Our results reveal the role of nitrate-responsive OsMADS27 and its downstream target genes in salt tolerance,providing a molecular mechanism for the enhancement of salt tolerance by nitrogen fertilizers in rice.OsMADS27 overexpression increased grain yield under salt stress in the presence of sufficient nitrate,suggestingthatOsMADS27 is a promising candidate for the improvementof salt tolerance inrice.
