OsDRE2 contributes to chitin-triggered response through its interaction with OsRLCK185

Area of Science:

• Plant immunology
• Molecular plant pathology
• Rice genetics

Background:

• The rice receptor-like cytoplasmic kinase 185 (OsRLCK185) is a key positive regulator of chitin-induced immune responses.
• OsRLCK185 mediates essential defense mechanisms such as MAP kinase activation, reactive oxygen species (ROS) production, and defense gene expression.

Purpose of the Study:

• To identify novel interactors of OsRLCK185 to elucidate its regulatory mechanisms in rice immunity.
• To investigate the role of identified interactors in OsRLCK185-mediated plant defense pathways.

Main Methods:

• Yeast two-hybrid screening and co-immunoprecipitation assays to identify and confirm OsRLCK185 interactors.
• Site-directed mutagenesis to determine the functional domains of OsDRE2a involved in OsRLCK185 interaction.
• RNA interference (RNAi) to assess the impact of OsDRE2a and OsDRE2b knockdown on chitin-induced ROS production.

Main Results:

• OsDRE2a, a rice homolog of yeast Dre2, was identified as a novel interactor of OsRLCK185, localizing to the plasma membrane.
• Conserved cysteine residues within the CIAPIN1 domain of OsDRE2a are essential for its interaction with OsRLCK185.
• OsRLCK185 phosphorylates OsDRE2a, and chitin treatment induces the expression of both OsDRE2a and OsDRE2b.
• RNAi-mediated reduction of OsDRE2a and OsDRE2b mRNA levels led to decreased chitin-induced ROS production.

Conclusions:

• OsDRE2a and OsDRE2b are novel components of the OsRLCK185-mediated immune signaling pathway in rice.
• OsDRE2 proteins are likely involved in regulating chitin-induced immune responses, potentially through their interaction and phosphorylation by OsRLCK185.