The receptor-like cytoplasmic kinase OsRLCK118 regulates plant development and basal immunity in rice (<i>Oryza sativa</i> L.)

Abstract

Receptor-like cytoplasmic kinases (RLCKs), which belong to a large subgroup of receptor-like kinases in plants, play crucial roles in plant development and immunity. However, their functions and regulatory mechanisms in plants remain unclear. Here, we report functional characterization of OsRLCK118 from the OsRLCK34 subgroup in rice (<italic>Oryza sativa</italic> L.). Expression of <italic>OsRLCK118</italic> could be induced by infections with <italic>Xanthomonas oryzae</italic> pv. <italic>oryzae</italic> (<italic>Xoo</italic>) strains PXO68 and PXO99. Silencing of <italic>OsRLCK118</italic> altered plant height, flag-leaf angle and second-top-leaf angle. Silencing of <italic>OsRLCK118</italic> also resulted in increasing susceptibility to <italic>Xoo</italic> and<italic> Magnaporthe oryzae</italic> (<italic>M. oryzae</italic>) in rice plants. <italic>OsRLCK118</italic> knock-out plants were more sensitive to bacterial blight whereas <italic>OsRLCK118</italic> overexpressor plants exhibited increased disease resistance. Expression levels of pathogenesis-related genes of <italic>OsPAL1</italic>, <italic>OsNH1</italic>, <italic>OsICS1</italic>, <italic>OsPR1a</italic>, <italic>OsPR5</italic> and <italic>OsPR10</italic> were reduced in the <italic>rlck118</italic> mutant compared to wild-type rice (Dongjin) and knock-out of <italic>OsRLCK118</italic> compromised the production of reactive oxygen species. These results suggest that <italic>OsRLCK118</italic> may modulate basal resistance to<italic> Xoo</italic> and <italic>M. oryzae</italic>, possibly through regulation of ROS burst and hormone mediated defense signaling pathway.