多肽信号分子调控生物体的生长发育过程,在动物、细菌、真菌中广泛存在,而植物多肽成分的信号分子直到1991年才首次报道,但随后即从植物中陆续分离出多种多肽类生长调节因子。快速碱化因子(rap id alkalin ization factor,RALF)就是其...多肽信号分子调控生物体的生长发育过程,在动物、细菌、真菌中广泛存在,而植物多肽成分的信号分子直到1991年才首次报道,但随后即从植物中陆续分离出多种多肽类生长调节因子。快速碱化因子(rap id alkalin ization factor,RALF)就是其中的一种,它广泛存在于植物中。被证明在植物多个器官的不同发育时期都表达,具有使植物组织生长的培养基碱化、抑制根生长等多种作用。现对RALF同源基因的特征以及表达情况、RALF多肽的结构及生理功能等进行介绍,为RALF的进一步研究提供参考。展开更多
Rapid alkalinization factors(RALFs)are cysteine-rich peptides that play important roles in a variety of biological processes,such as cell elongation and immune signaling.Recent studies in Arabidopsis have shown that R...Rapid alkalinization factors(RALFs)are cysteine-rich peptides that play important roles in a variety of biological processes,such as cell elongation and immune signaling.Recent studies in Arabidopsis have shown that RALFs regulate pollen tube growth via plasma membrane receptor-like kinases(RLKs).However,the downstream signal transduction mechanisms of RLKs in pollen tubes are unknown.Here,we identified PbrRALF2,a pear(Pyrus bretschneideri)pollen RALF peptide that inhibits pollen tube growth.We found that PbrRALF2 interacts with a malectin-like domain-containing RLK,PbrCrRLK1L13.The relative affinity between PbrRALF2 and PbrCrRLK1L13 was at the submicromolar level,which is consistent with the values of ligand–receptor kinase pairs and the physiological concentration for PbrRALF2-mediated inhibition of pollen tube growth.After binding to its extracellular domain,PbrRALF2 activated the phosphorylation of PbrCrRLK1L13 in a dose-dependent manner.We further showed that the MAP kinase PbrMPK18 is a downstream target of PbrCrRLK1L13 that mediates PbrRALF2-elicited reactive oxygen species(ROS)production.The excessive accumulation of ROS inhibits pollen tube growth.We show that MPK acts as a mediator for CrRLK1L to stimulate ROS production,which might represent a general mechanism by which RALF and CrRLK1L function in signaling pathways.展开更多
文摘多肽信号分子调控生物体的生长发育过程,在动物、细菌、真菌中广泛存在,而植物多肽成分的信号分子直到1991年才首次报道,但随后即从植物中陆续分离出多种多肽类生长调节因子。快速碱化因子(rap id alkalin ization factor,RALF)就是其中的一种,它广泛存在于植物中。被证明在植物多个器官的不同发育时期都表达,具有使植物组织生长的培养基碱化、抑制根生长等多种作用。现对RALF同源基因的特征以及表达情况、RALF多肽的结构及生理功能等进行介绍,为RALF的进一步研究提供参考。
基金This work was supported by the National Key Research and Development Program of China(2018YFD1000107)the National Natural Science Foundation of China(31772256 and 31772276)the Priority Academic Program Development of Jiangsu Higher Education Institutions.
文摘Rapid alkalinization factors(RALFs)are cysteine-rich peptides that play important roles in a variety of biological processes,such as cell elongation and immune signaling.Recent studies in Arabidopsis have shown that RALFs regulate pollen tube growth via plasma membrane receptor-like kinases(RLKs).However,the downstream signal transduction mechanisms of RLKs in pollen tubes are unknown.Here,we identified PbrRALF2,a pear(Pyrus bretschneideri)pollen RALF peptide that inhibits pollen tube growth.We found that PbrRALF2 interacts with a malectin-like domain-containing RLK,PbrCrRLK1L13.The relative affinity between PbrRALF2 and PbrCrRLK1L13 was at the submicromolar level,which is consistent with the values of ligand–receptor kinase pairs and the physiological concentration for PbrRALF2-mediated inhibition of pollen tube growth.After binding to its extracellular domain,PbrRALF2 activated the phosphorylation of PbrCrRLK1L13 in a dose-dependent manner.We further showed that the MAP kinase PbrMPK18 is a downstream target of PbrCrRLK1L13 that mediates PbrRALF2-elicited reactive oxygen species(ROS)production.The excessive accumulation of ROS inhibits pollen tube growth.We show that MPK acts as a mediator for CrRLK1L to stimulate ROS production,which might represent a general mechanism by which RALF and CrRLK1L function in signaling pathways.
