To infect plants, Pseudomonas syringae pv. tomato delivers ~30 type III effector proteins into host cells, many of which interfere with PAMP-triggered immunity (PTI). One effector, AvrPtoB, suppresses PTI using a central domain to bind host BAK1, a kinase that acts with several pattern recognition receptors to activate defense signaling. A second AvrPtoB domain binds and suppresses the PTI-associated kinase Bti9 but is conversely recognized by the protein kinase Pto to activate effector-triggered immunity. We report the crystal structure of the AvrPtoB-BAK1 complex, which revealed structural similarity between these two AvrPtoB domains, suggesting that they arose by intragenic duplication. The BAK1 kinase domain is structurally similar to Pto, and a conserved region within both BAK1 and Pto interacts with AvrPtoB. BAK1 kinase activity is inhibited by AvrPtoB, and mutations at the interaction interface disrupt AvrPtoB virulence activity. These results shed light on a structural mechanism underlying host-pathogen coevolution.
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http://dx.doi.org/10.1016/j.chom.2011.10.013 | DOI Listing |
J Agric Food Chem
December 2024
Key Laboratory of Plant Hormones and Molecular Breeding of Chongqing, School of Life Sciences, Chongqing University, Chongqing 401331, China.
Fruit is an essential part of the human diet, and postharvest fungal diseases are the major cause of fruit postharvest losses worldwide. Pathogen-associated molecular patterns (PAMPs) are important elicitors from microbes, and the recognition between microbial PAMPs and plant receptors leads to PAMP-triggered immunity. Here, we identified a PAMP, PdEIX, that is an important protein elicitor with plant immunity-inducing activity, from the citrus green mold pathogen .
View Article and Find Full Text PDFNat Plants
December 2024
National Key Lab of Agricultural Microbiology, Hubei Hongshan Laboratory, College of Life Science and Technology, Huazhong Agricultural University, Wuhan, China.
Ligand-induced receptor and co-receptor heterodimerization is a common mechanism in receptor kinase (RK) signalling activation. SERINE-RICH ENDOGENOUS PEPTIDEs (SCOOPs) mediate the complex formation of Arabidopsis RK MIK2 and co-receptor BAK1, triggering immune responses. Through structural, biochemical and genetic analyses, we demonstrate that SCOOPs use their SxS motif and adjacent residues to bind MIK2 and the carboxy-terminal GGR residues to link MIK2 to BAK1.
View Article and Find Full Text PDFNat Plants
December 2024
School of Life Sciences, Westlake University, Institute of Biology, Westlake Institute for Advanced Study, Westlake Laboratory of Life Sciences and Biomedicine, Hangzhou, China.
Plant receptor kinases (RKs) are critical for transmembrane signalling involved in various biological processes including plant immunity. MALE DISCOVERER1-INTERACTING RECEPTOR-LIKE KINASE 2 (MIK2) is a unique RK that recognizes a family of immunomodulatory peptides called SERINE-RICH ENDOGENOUS PEPTIDEs (SCOOPs) and activates pattern-triggered immunity responses. However, the precise mechanisms underlying SCOOP recognition and activation of MIK2 remain poorly understood.
View Article and Find Full Text PDFMol Plant Pathol
November 2024
State Key Laboratory of Resource Insects, Institute of Sericulture and Systems Biology, Southwest University, Chongqing, China.
Ciboria shiraiana is a necrotrophic fungus that causes mulberry sclerotinia disease resulting in huge economic losses in agriculture. During infection, the fungus uses immunity elicitors to induce plant tissue necrosis that could facilitate its colonization on plants. However, the key elicitors and immune mechanisms remain unclear in C.
View Article and Find Full Text PDFInt J Biol Macromol
December 2024
State Key Laboratory of Resource Insects, Southwest University, Chongqing, China. Electronic address:
The plant apoplast is a key battleground in the initial stages of interaction between the plant and pathogen. Despite its importance, few apoplastic effectors have been characterized to date. Here, we identified Ssh1296, a conserved apoplastic effector from Scleromitrula shiraiana.
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