How Does OsCERK1 Switch Between Immunity and Symbiosis Functions in Rice?

OsCERK1, a receptor-like kinase (RLK) containing a lysin motif (LysM), is involved in both chitin-triggered immunity and arbuscular mycorrhizal (AM) symbiosis. The mechanism of how OsCERK1 regulates these responses is still unclear. A possible explanation is that OsCERK1 might change its function depending on its partner molecules. As a partner of OsCERK1 for AM symbiosis, OsRLK1, OsRLK4, and OsRLK7, which showed gene expression in roots were focused. However, single mutagenesis of these genes did not cause severe reduction in AM colonization. Besides, a symbiosis receptor-like kinase containing leucine-rich repeats (LRR) motif in rice, OsSYMRK, plays an important role in AM symbiosis.