A specialist herbivore suppresses host plant resistance by inducing a
leucine-rich repeat receptor-like kinase
Abstract
The mechanisms by which herbivores induce plant defenses are well
studied. However, how specialized herbivores suppress plant resistance
is still poorly understood. Here, we discovered a rice (Oryza sativa)
leucine-rich repeat receptor-like kinase, OsLRR-RLK2, which is induced
upon attack by gravid females of a specialist piercing-sucking
herbivore, the brown planthopper (BPH, Nilaparvata lugens). Silencing
OsLRR-RLK2 decreases the constitutive activity of mitogen-activated
protein kinase (OsMPK6) and alters BPH-induced transcript levels of
several defense-related WRKY transcription factors. Moreover, silencing
OsLRR-RLK2 reduces BPH-induction of jasmonic acid and ethylene but
promotes the biosynthesis of both elicited salicylic acid and H2O2;
silencing also enhances the production of volatiles emitted from rice
plants infested with gravid BPH females. These changes decrease BPH
preference and performance in the glasshouse and the field. Our study
identifies OsLRR-RLK2 as a major susceptibility factor of rice against
BPH. It is likely to be employed by BPH to suppress host plant defenses
for its own benefit via signaling crosstalk and/or changing the plant’s
defense-related signaling profile.