Suppression of a leucine‐rich repeat receptor‐like kinase enhances host plant resistance to a specialist herbivore

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. These findings suggest that OsLRR‐RLK2, by regulating the plant's defense‐related signaling profile, increases the susceptibility of rice to BPH, and that BPH infestation influences the expression of OsLRR‐RLK2, suppressing the resistance of rice to BPH.

Silencing an E3 Ubiquitin Ligase Gene OsJMJ715 Enhances the Resistance of Rice to a Piercing-Sucking Herbivore by Activating ABA and JA Signaling Pathways

“…To gain further insight into the mechanism underlying OsJMJ715-mediated rice resistance to BPH, we measured levels of JA, JA-isoleucine (JA-Ile), and ABA in WT and ir JMJ plants in response to gravid BPH female attack. As previously found [ 32 ], levels of JA and JA-Ile were induced quickly and continuously during gravid BPH female infestation ( Figure 5 A,B). Silencing OsJMJ715 did not influence the constitutive level of JA but slightly enhanced the constitutive level of JA-Ile ( Figure 5 A,B).…”

The N-terminal subunit of vitellogenin in planthopper eggs and saliva acts as a reliable elicitor that induces defenses in rice

“…JA- and ethylene-mediated signaling pathways play a central role in regulating the resistance of rice to BPH (Zhou et al, 2009; Lu et al, 2014; Xu et al, 2021). Moreover, infestation by gravid BPH females (feeding + oviposition) induces the production of JA and JA-Ile and inhibits the production of ethylene in rice, whereas infestation by nymphs does not (Li, 2015; Ji et al, 2017; Ye et al, 2017; Ye et al, 2020; Xu et al, 2021). Hence, we wondered if NlVgN plays a role in modulating the biosynthesis of these phytohormones in rice.…”

Rice functional genomics: decades’ efforts and roads ahead

“…OsLRR-RLK1, an early responsive leucine-rich re- peat receptor-like kinase, acts upstream of MPK cascades and positively regulates defense-related MPKs and WRKY transcription factors, as well as plant resistance towards SSB (Hu et al, 2018a). Suppression of OsLRR-RLK2 decreases BPH preference and performance by reducing the constitutive activity of OsMPK6 and transcript levels of defense-related WRKY transcription factors (Ye et al, 2020). OsERF3 affects early components of herbivore-induced defense responses by suppressing MAPK repressors and is a positive regulator of plant resistance to SSB and a susceptibility factor against BPH (Lu et al, 2011).…”