Pseudomonas syringae effector protein AvrB perturbs Arabidopsis hormone signaling by activating MAP kinase 4.
Pathogenic microbes often modulate phytohormone physiology in the host to their advantage. We previously showed that the Pseudomonas syringae effector protein AvrB perturbs hormone signaling, as exemplified by upregulated expression of jasmonic acid response genes, and enhances plant susceptibility. Here we show that these effects of AvrB require the Arabidopsis mitogen-activated protein kinase MAP kinase 4 (MPK4), HSP90 chaperone components, and the AvrB-interacting protein, RIN4. AvrB interacts with MPK4 and the HSP90 chaperone, and AvrB induces MPK4 activation in a manner promoted by HSP90; RIN4 likely acts downstream of MPK4. These findings link Arabidopsis proteins MPK4, HSP90, and RIN4 into a pathway that P. syringae AvrB activates for the benefit of the bacterium, perturbing hormone signaling and enhancing plant susceptibility.
Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing, China.
Haitao
H
Cui
Yujing
Y
Wang
Li
L
Xue
Jinfang
J
Chu
Cunyu
C
Yan
Jihong
J
Fu
Mingsheng
M
Chen
Roger W
RW
Innes
Jian-Min
JM
Zhou
D017360:Arabidopsis / Q000382:microbiology*; D029681:Arabidopsis Proteins / Q000096:biosynthesis* / Q000378:metabolism; D001426:Bacterial Proteins / Q000502:physiology*; D002352:Carrier Proteins / Q000378:metabolism; D018841:HSP90 Heat-Shock Proteins / Q000378:metabolism; D054884:Host-Pathogen Interactions; D047908:Intracellular Signaling Peptides and Proteins; D020928:Mitogen-Activated Protein Kinases / Q000096:biosynthesis*; D025941:Protein Interaction Mapping; D044224:Pseudomonas syringae / Q000502:physiology*; D015398:Signal Transduction; D037521:Virulence Factors / Q000502:physiology*
D029681:Arabidopsis Proteins; C100931:AvrB protein, Pseudomonas syringae; D001426:Bacterial Proteins; D002352:Carrier Proteins; D018841:HSP90 Heat-Shock Proteins; D047908:Intracellular Signaling Peptides and Proteins; C453279:RIN4 protein, Arabidopsis; D037521:Virulence Factors; C436292:AtMPK4 protein, Arabidopsis; D020928:Mitogen-Activated Protein Kinases