Receptor-like cytoplasmic kinases integrate signaling from multiple plant immune receptors and are targeted by a Pseudomonas syringae effector.
Cell-surface-localized plant immune receptors, such as FLS2, detect pathogen-associated molecular patterns (PAMPs) and initiate PAMP-triggered immunity (PTI) through poorly understood signal-transduction pathways. The pathogenic Pseudomonas syringae effector AvrPphB, a cysteine protease, cleaves the Arabidopsis receptor-like cytoplasmic kinase PBS1 to trigger cytoplasmic immune receptor RPS5-specified effector-triggered immunity (ETI). Analyzing the function of AvrPphB in plants lacking RPS5, we find that AvrPphB can inhibit PTI by cleaving additional PBS1-like (PBL) kinases, including BIK1, PBL1, and PBL2. In unstimulated plants, BIK1 and PBL1 interact with FLS2 and are rapidly phosphorylated upon FLS2 activation by its ligand flg22. Genetic and molecular analyses indicate that BIK1, and possibly PBL1, PBL2, and PBS1, integrate immune signaling from multiple immune receptors. Whereas AvrPphB-mediated degradation of one of these kinases, PBS1, is monitored by RPS5 to initiate ETI, this pathogenic effector targets other PBL kinases for PTI inhibition.
Zhang
Jie
J
National Institute of Biological Sciences, Beijing 102206, China.
Li
Wei
W
National Institute of Biological Sciences, Beijing 102206, China.
Xiang
Tingting
T
National Institute of Biological Sciences, Beijing 102206, China; State Key Laboratory of Plant Physiology and Biochemistry, College of Biological Sciences, China Agricultural University, Beijing 100094, China.
Liu
Zixu
Z
National Institute of Biological Sciences, Beijing 102206, China.
Laluk
Kristin
K
Department of Botany and Plant Pathology, Purdue University, West Lafayette, IN 47907, USA.
Ding
Xiaojun
X
National Institute of Biological Sciences, Beijing 102206, China.
Zou
Yan
Y
National Institute of Biological Sciences, Beijing 102206, China.
Gao
Minghui
M
National Institute of Biological Sciences, Beijing 102206, China.
Zhang
Xiaojuan
X
National Institute of Biological Sciences, Beijing 102206, China.
Chen
She
S
National Institute of Biological Sciences, Beijing 102206, China.
Mengiste
Tesfaye
T
Department of Botany and Plant Pathology, Purdue University, West Lafayette, IN 47907, USA.
Zhang
Yuelin
Y
National Institute of Biological Sciences, Beijing 102206, China.
Zhou
Jian-Min
JM
National Institute of Biological Sciences, Beijing 102206, China. Electronic address: zhoujianmin@nibs.ac.cn.
D017360:Arabidopsis / Q000276:immunology* / Q000382:microbiology*; D029681:Arabidopsis Proteins / Q000378:metabolism*; D001426:Bacterial Proteins / Q000378:metabolism*; D010766:Phosphorylation; D010940:Plant Proteins / Q000378:metabolism*; D011485:Protein Binding; D011494:Protein Kinases / Q000378:metabolism; D017346:Protein Serine-Threonine Kinases / Q000378:metabolism*; D044224:Pseudomonas syringae / Q000472:pathogenicity*; D015398:Signal Transduction; D037521:Virulence Factors / Q000378:metabolism*
D029681:Arabidopsis Proteins; D001426:Bacterial Proteins; D010940:Plant Proteins; C465630:RPS5 protein, Arabidopsis; D037521:Virulence Factors; C500179:avrPphB protein, Pseudomonas syringae; D011494:Protein Kinases; C411853:FLS2 protein, Arabidopsis; C477340:PBS1 protein, Arabidopsis; C509522:BIK1 protein, Arabidopsis; D017346:Protein Serine-Threonine Kinases