OsBSK1-2, an Orthologous of AtBSK1, Is Involved in Rice Immunity

The brassinosteroid-SIGNALING KINASE (BSK) belongs to the receptor-like cytoplasmic kinase XII subgroup. BSK1 regulates development and immunity in <i>Arabidopsis</i>. However, the function of rice (<i>Oryza sativa</i>) BSK1 is largely unknown. Here, we report that the expression level of <i>OsBSK1-2</i> is induced after a chitin or fagellin22 (flg22) treatment. Silencing <i>OsBSK1-2</i> in rice results in compromised responses to chitin- or flg22-triggered immunity and resistance to <i>Magnaporthe oryzae</i>, but does not alter the plant's architecture nor reduce plant responses to brassinosteroid signaling. Our study reveals that OsBSK1-2 functions as a major regulator in rice plant immunity.