Plants utilize nucleotide-binding,leucine-rich repeat receptors(NLRs)to detect pathogen effectors,leading to effector-triggered immunity.The NLR ZAR1 indirectly recognizes the Xanthomonas campestris pv.campestris effe...Plants utilize nucleotide-binding,leucine-rich repeat receptors(NLRs)to detect pathogen effectors,leading to effector-triggered immunity.The NLR ZAR1 indirectly recognizes the Xanthomonas campestris pv.campestris effector AvrAC and Pseudomonas syringae effector HopZIa by associating with closely related receptor-like cytoplasmic kinase subfamily XII-2(RLCK XII-2)members RKS1 and ZED1,respectively.ZAR1,RKS1,and the AvrAC-modified decoy PBL2ump form a pentameric resistosome in vitro,and the ability of resistosome formation is required for AvrAC-triggered cell death and disease resistance.However,it remains unknown whether the effectors induce ZAR1 oligomerization in the plant cell.In this study,we show that both AvrAC and HopZ1 a can induce oligomerization of ZAR1 in Arabidopsis protoplasts.Residues mediating ZAR1-ZED1 interaction are indispensable for HopZIa-induced ZAR1 oligomerization in vivo and disease resistance.In addition,ZAR1 residues required for the assembly of ZAR1 resistosome in vitro are also essential for HopZIa-induced ZAR1 oligomerization in vivo and disease resistance.Our study provides evidence that pathogen effectors induce ZAR1 resistosome formation in the plant cell and that the resistosome formation triggers disease resistance.展开更多
Plants utilize intracellular nucleotide-binding leucine-rich repeat domain-containing receptors (NLRs) to recognize pathogen effectors and induce a robust defense response named effector-triggered immunity (ETI). The ...Plants utilize intracellular nucleotide-binding leucine-rich repeat domain-containing receptors (NLRs) to recognize pathogen effectors and induce a robust defense response named effector-triggered immunity (ETI). The Arabidopsis NLR protein HOPZ-ACTIVATED RESISTANCE 1 (ZAR1) forms a precomplex with HOPZ-ETI-DEFICIENT 1 (ZED1),a receptor-like cytoplasmic kinase (RLCK) XII-2 subfamily member, to recognize the Pseudomonas syringae effector HopZ1 a. We previously described a dominant mutant of Arabi-dopsis ZED1, zed1-D, which displays temperature-sensitive autoimmunity in a ZAR1-dependent manner. Here, we report that the RLCKs SUPPRESSOR OF ZED1-D1 (SZE1) and SZE2 associate with the ZAR1-ZED1 complex and are required for the ZED7-D-activated autoimmune response and HopZ1a-triggered immunity. We show that SZE1 but not SZE2 has autophosphorylation activity, and that the N-terminal myristoylation of both SZE1 and SZE2 is critical for their plasma membrane localization and ZED1-D-activated autoimmunity. Furthermore, we demonstrate that SZE1 and SZE2 both interact with ZAR1 to form ja functional complex and are required for resistance against P. syringae pv. tomato DC3000 ex-pressing HopZIa. We also provide evidence that SZE1 and SZE2 interact with HopZ1a and function together with ZED1 to change the intramolecular interactions of ZAR1, leading to its activation. Taken together, our re-sults reveal SZE1 and SZE2 as critical signaling components of HopZ1a-triggered immunity.展开更多
基金grants from National Natural Science Foundation of China(31521001)Ministry of Science and Technology of the People's Republic of China(2016YFD0100601)the Chinese Academy of Sciences international cooperation key project grant GJHZ1311,and the State Key Laboratory of Plant Genomics(SKLPG2016B-2)to J.-M.Z.
文摘Plants utilize nucleotide-binding,leucine-rich repeat receptors(NLRs)to detect pathogen effectors,leading to effector-triggered immunity.The NLR ZAR1 indirectly recognizes the Xanthomonas campestris pv.campestris effector AvrAC and Pseudomonas syringae effector HopZIa by associating with closely related receptor-like cytoplasmic kinase subfamily XII-2(RLCK XII-2)members RKS1 and ZED1,respectively.ZAR1,RKS1,and the AvrAC-modified decoy PBL2ump form a pentameric resistosome in vitro,and the ability of resistosome formation is required for AvrAC-triggered cell death and disease resistance.However,it remains unknown whether the effectors induce ZAR1 oligomerization in the plant cell.In this study,we show that both AvrAC and HopZ1 a can induce oligomerization of ZAR1 in Arabidopsis protoplasts.Residues mediating ZAR1-ZED1 interaction are indispensable for HopZIa-induced ZAR1 oligomerization in vivo and disease resistance.In addition,ZAR1 residues required for the assembly of ZAR1 resistosome in vitro are also essential for HopZIa-induced ZAR1 oligomerization in vivo and disease resistance.Our study provides evidence that pathogen effectors induce ZAR1 resistosome formation in the plant cell and that the resistosome formation triggers disease resistance.
基金National Natural Science Foundation of China (31471160)the Strategic Priority Research Program of Chinese Academy of Sciences PCDB27030102).
文摘Plants utilize intracellular nucleotide-binding leucine-rich repeat domain-containing receptors (NLRs) to recognize pathogen effectors and induce a robust defense response named effector-triggered immunity (ETI). The Arabidopsis NLR protein HOPZ-ACTIVATED RESISTANCE 1 (ZAR1) forms a precomplex with HOPZ-ETI-DEFICIENT 1 (ZED1),a receptor-like cytoplasmic kinase (RLCK) XII-2 subfamily member, to recognize the Pseudomonas syringae effector HopZ1 a. We previously described a dominant mutant of Arabi-dopsis ZED1, zed1-D, which displays temperature-sensitive autoimmunity in a ZAR1-dependent manner. Here, we report that the RLCKs SUPPRESSOR OF ZED1-D1 (SZE1) and SZE2 associate with the ZAR1-ZED1 complex and are required for the ZED7-D-activated autoimmune response and HopZ1a-triggered immunity. We show that SZE1 but not SZE2 has autophosphorylation activity, and that the N-terminal myristoylation of both SZE1 and SZE2 is critical for their plasma membrane localization and ZED1-D-activated autoimmunity. Furthermore, we demonstrate that SZE1 and SZE2 both interact with ZAR1 to form ja functional complex and are required for resistance against P. syringae pv. tomato DC3000 ex-pressing HopZIa. We also provide evidence that SZE1 and SZE2 interact with HopZ1a and function together with ZED1 to change the intramolecular interactions of ZAR1, leading to its activation. Taken together, our re-sults reveal SZE1 and SZE2 as critical signaling components of HopZ1a-triggered immunity.
