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
This study explores the broad-spectrum application of OsRALF26,a small secreted peptide belonging to the rapid alkalinization factor(RALF)family in rice.We found that the rice genome carries numerous lineage-specific ...This study explores the broad-spectrum application of OsRALF26,a small secreted peptide belonging to the rapid alkalinization factor(RALF)family in rice.We found that the rice genome carries numerous lineage-specific OsRALFs,suggesting that this evolutionary expansion could be the result of an arms race with pathogens.Among them,we focused on the Oryza-specific Os RALF26 and its closest homolog,OsRALF27,analyzing their effects across a range of plant species from monocots to dicots.The exogenous application of OsRALF26 significantly reduced bacterial populations in rice challenged with Xanthomonas oryzae pv.oryzae(Xoo)and in Arabidopsis and tomato challenged with Pseudomonas syringae pv.tomato DC3000(Pst DC3000),whereas Os RALF27 did not enhance resistance.展开更多
The molecular mechanism by which plants defend against plant root-knot nematodes(RKNs)is largely unknown.The plant receptor kinase FERONIA and its peptide ligands,rapid alkalinization factors(RALFs),regulate plant imm...The molecular mechanism by which plants defend against plant root-knot nematodes(RKNs)is largely unknown.The plant receptor kinase FERONIA and its peptide ligands,rapid alkalinization factors(RALFs),regulate plant immune responses and cell expansion,which are two important factors for successful RKN parasitism.In this study,we found that mutation of FERONIA in Arabidopsis thaliana resulted in plants showing low susceptibility to the RKN Meloidogyne incognita.To identify the underlying mechanisms associated with this phenomenon,we identified 18 novel RALF-likes from multiple species of RKNs and showed that two RALF-likes(i.e.,MiRALF1 and MiRALF3)from M.incognita were expressed in the esophageal gland with high expression during the parasitic stages of nematode development.These nematode RALF-likes also possess the typical activities of plant RALFs and can directly bind to the extracellular domain of FERONIA to modulate specific steps of nematode parasitism-related immune responses and cell expansion.Genetically,both MiRALF1/3 and FERONIA are required for RKN parasitism in Arabidopsis and rice.Collectively,our study suggests that nematode-encoded RALFs facilitate parasitism via plant-encoded FERONIA and provides a novel paradigm for studying host-pathogen interactions.展开更多
The molecular links between extracellular signals and the regulation of localized protein synthesis in plant cells are poorly understood.Here,we show that in Arabidopsis thaliana,the extracellular peptide RALF1 and it...The molecular links between extracellular signals and the regulation of localized protein synthesis in plant cells are poorly understood.Here,we show that in Arabidopsis thaliana,the extracellular peptide RALF1 and its receptor,the FERONIA receptor kinase,promote root hair(RH)tip growth by modulating protein synthesis.We found that RALF1 promotes FERONIA-mediated phosphorylation of elF4E1,a eukaryotic translation initiation factor that plays a crucial role in the control of mRNA translation rate.Phosphorylated elF4E1 increases mRNA affinity and modulates mRNA translation and,thus,protein synthesis.The mRNAs targeted by the RALF1-FERONIA-elF4E1 module include ROP2 and RSL4,which are important regulators of RH cell polarity and growth.RALF1 and FERONIA are expressed in a polar manner in RHs,which facilitate elF4E1 polar丨ocalization and thus may control local f?OP2 translation.Moreover,we demonstrated that high-level accumulation of RSL4 exerts negative-feedback regulation of RALF1 expression by directly binding the RALF1 gene promoter,determining the final RH size.Our study reveals that the link between RALF1-FERONIA signaling and protein synthesis constitutes a novel component regulating cell expansion in these polar growing cells.展开更多
Pollen tube growth is essential for successful double fertilization, which is critical for grain yield in crop plants. Rapid alkalinization factors(RALFs) function as ligands for signal transduction during fertilizati...Pollen tube growth is essential for successful double fertilization, which is critical for grain yield in crop plants. Rapid alkalinization factors(RALFs) function as ligands for signal transduction during fertilization. However, functional studies on RALF in monocot plants are lacking.Herein, we functionally characterized two pollen-specific RALFs in rice(Oryza sativa) using multiple clustered regularly interspaced palindromic repeats(CRISPR)/CRISPR-associated protein 9-induced loss-of-function mutants,peptide treatment, expression analyses, and tag reporter lines. Among the 41 RALF members in rice, OsRALF17 was specifically expressed at the highest level in pollen and pollen tubes.Exogenously applied OsRALF17 or OsRALF19peptide inhibited pollen tube germination and elongation at high concentrations but enhanced tube elongation at low concentrations, indicating growth regulation. Double mutants of OsRALF17 and OsRALF19(ralf17/19) exhibited almost full male sterility with defects in pollen hydration, germination, and tube elongation,which was partially recovered by exogenous treatment with OsRALF17 peptide. This study revealed that two partially functionally redundant OsRALF17 and OsRALF19 bind to Oryza sativa male-gene transfer defective 2(OsMTD2) and transmit reactive oxygen species signals for pollen tube germination and integrity maintenance in rice. Transcriptomic analysis confirmed their common downstream genes, in osmtd2 and ralf17/19. This study provides new insights into the role of RALF, expanding our knowledge of the biological role of RALF in regulating rice fertilization.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.
基金supported by the National Research Foundation of Korea grant funded by the Korea government(Grant Nos.NRF-2020R1A2C1007778 and RS-2024-00454908)。
文摘This study explores the broad-spectrum application of OsRALF26,a small secreted peptide belonging to the rapid alkalinization factor(RALF)family in rice.We found that the rice genome carries numerous lineage-specific OsRALFs,suggesting that this evolutionary expansion could be the result of an arms race with pathogens.Among them,we focused on the Oryza-specific Os RALF26 and its closest homolog,OsRALF27,analyzing their effects across a range of plant species from monocots to dicots.The exogenous application of OsRALF26 significantly reduced bacterial populations in rice challenged with Xanthomonas oryzae pv.oryzae(Xoo)and in Arabidopsis and tomato challenged with Pseudomonas syringae pv.tomato DC3000(Pst DC3000),whereas Os RALF27 did not enhance resistance.
基金the National Natural Science Foundation of China(NSFC-31871396,31571444,31400232,and 31672012)the Young Elite Scientist Sponsorship Program from CAST(YESS20160001)the Science and Technology Inn ovation Project of Chinese Academy of Agricultural Sciences(2060302-51).
文摘The molecular mechanism by which plants defend against plant root-knot nematodes(RKNs)is largely unknown.The plant receptor kinase FERONIA and its peptide ligands,rapid alkalinization factors(RALFs),regulate plant immune responses and cell expansion,which are two important factors for successful RKN parasitism.In this study,we found that mutation of FERONIA in Arabidopsis thaliana resulted in plants showing low susceptibility to the RKN Meloidogyne incognita.To identify the underlying mechanisms associated with this phenomenon,we identified 18 novel RALF-likes from multiple species of RKNs and showed that two RALF-likes(i.e.,MiRALF1 and MiRALF3)from M.incognita were expressed in the esophageal gland with high expression during the parasitic stages of nematode development.These nematode RALF-likes also possess the typical activities of plant RALFs and can directly bind to the extracellular domain of FERONIA to modulate specific steps of nematode parasitism-related immune responses and cell expansion.Genetically,both MiRALF1/3 and FERONIA are required for RKN parasitism in Arabidopsis and rice.Collectively,our study suggests that nematode-encoded RALFs facilitate parasitism via plant-encoded FERONIA and provides a novel paradigm for studying host-pathogen interactions.
基金grants from the National Natural Science Foundation of China(NSFC-31400232,31871396,31571444)Young Elite Scientist Sponsorship program of CAST(YESS20160001)+1 种基金the Open Research Fund of the State Key Laboratory of Hybrid Rice(Hunan Hybrid Rice Research Center)to F.Y.and from ANPCyT(PICT2016-0132 and PICT2017-0066),ICGEB(CRP/ARG16-03)Instituto Milenio iBio-Iniciativa Cientffica Milenio MINECON to J.M.E.
文摘The molecular links between extracellular signals and the regulation of localized protein synthesis in plant cells are poorly understood.Here,we show that in Arabidopsis thaliana,the extracellular peptide RALF1 and its receptor,the FERONIA receptor kinase,promote root hair(RH)tip growth by modulating protein synthesis.We found that RALF1 promotes FERONIA-mediated phosphorylation of elF4E1,a eukaryotic translation initiation factor that plays a crucial role in the control of mRNA translation rate.Phosphorylated elF4E1 increases mRNA affinity and modulates mRNA translation and,thus,protein synthesis.The mRNAs targeted by the RALF1-FERONIA-elF4E1 module include ROP2 and RSL4,which are important regulators of RH cell polarity and growth.RALF1 and FERONIA are expressed in a polar manner in RHs,which facilitate elF4E1 polar丨ocalization and thus may control local f?OP2 translation.Moreover,we demonstrated that high-level accumulation of RSL4 exerts negative-feedback regulation of RALF1 expression by directly binding the RALF1 gene promoter,determining the final RH size.Our study reveals that the link between RALF1-FERONIA signaling and protein synthesis constitutes a novel component regulating cell expansion in these polar growing cells.
基金supported by grants from the National Research Foundation, Ministry of Education, Science and Technology (2019R1C1C1002636 and RS-2023-00217064 to Y.-J.K., 2021R1A4A2001968 to S.T.K., and 2021M3E5E6025387 and 2021R1A5A1032428 to K.-H.J.)the New Breeding Technologies Development Program (PJ01661002 to K.-H.J.)the Rural Development Administration, Republic of Korea。
文摘Pollen tube growth is essential for successful double fertilization, which is critical for grain yield in crop plants. Rapid alkalinization factors(RALFs) function as ligands for signal transduction during fertilization. However, functional studies on RALF in monocot plants are lacking.Herein, we functionally characterized two pollen-specific RALFs in rice(Oryza sativa) using multiple clustered regularly interspaced palindromic repeats(CRISPR)/CRISPR-associated protein 9-induced loss-of-function mutants,peptide treatment, expression analyses, and tag reporter lines. Among the 41 RALF members in rice, OsRALF17 was specifically expressed at the highest level in pollen and pollen tubes.Exogenously applied OsRALF17 or OsRALF19peptide inhibited pollen tube germination and elongation at high concentrations but enhanced tube elongation at low concentrations, indicating growth regulation. Double mutants of OsRALF17 and OsRALF19(ralf17/19) exhibited almost full male sterility with defects in pollen hydration, germination, and tube elongation,which was partially recovered by exogenous treatment with OsRALF17 peptide. This study revealed that two partially functionally redundant OsRALF17 and OsRALF19 bind to Oryza sativa male-gene transfer defective 2(OsMTD2) and transmit reactive oxygen species signals for pollen tube germination and integrity maintenance in rice. Transcriptomic analysis confirmed their common downstream genes, in osmtd2 and ralf17/19. This study provides new insights into the role of RALF, expanding our knowledge of the biological role of RALF in regulating rice fertilization.
