Phytophthora sojae leucine-rich repeat receptor-like kinases: diverse and essential roles in development and pathogenicity

Leucine-rich repeat receptor-like kinases (LRR-RLKs) are critical signal receptors in plant development and defense. Like plants, oomycete pathogen genomes also harbor LRR-RLKs, but their functions remain largely unknown. Here, we systematically characterize all the 24 LRR-RLK genes (PsRLKs) from Phytophthora sojae, which is a model of oomycete pathogens. Although none of them was required for vegetative growth, the specific PsRLKs are important for stress responses, zoospore production, zoospores chemotaxis, and pathogenicity. Interestingly, the G alpha subunit PsGPA1 interacts with the five chemotaxis-related PsRLKs via their intracellular kinase domains, and expression of PsGPA1 gene is downregulated in the three mutants (Delta PsRLK17/22/24). Moreover, we generated the PsRLK-PsRLK interaction network of P. sojae and found that PsRLK21, together with PsRLK10 or PsRLK17, regulate virulence by direct association. Taken together, our results reveal the diverse roles of LRR-RLKs in modulating P. sojae development, interaction with soybean, and responses to diverse environmental factors.

Automated summary

The study reveals that PsRLKs play critical roles in stress responses, zoospore chemotaxis, pathogenicity, and interaction with soybean in Phytophthora sojae. Specifically, PsRLK21 interacts with PsRLK10 or PsRLK17 to regulate virulence.