Liu Mengyu, Li Huijing, Chen Yumeng, Wu Zhixin, Wu Siwen, Zhang Jing, Sun Rui, Lou Yonggen, Lu Jing, Li Ran
State Key Laboratory of Rice Biology and Breeding, Zhejiang Key Laboratory of Biology and Ecological Regulation of Crop Pathogens and Insects, Institute of Insect Sciences, Zhejiang University, Hangzhou, 310058, China.
Zhejiang Provincial Center for Disease Control and Prevention, Hangzhou, 310051, China.
New Phytol. 2025 May;246(4):1834-1847. doi: 10.1111/nph.70059. Epub 2025 Apr 1.
Plant defense against herbivores is primarily regulated by the phytohormone jasmonate (JA). At the core, JA signaling is the MYC2 transcription factor (TF) that regulates the expression of an extensive array of defense-related genes. However, the regulatory mechanisms underlying MYC2-mediated herbivore resistance in rice are not fully understood. We employed brown planthopper (BPH) bioassays, transcriptional activation assays, transcriptome profiling, targeted metabolomics and cleavage under targets and tagmentation-sequencing analysis to investigate the biological function and regulatory mechanism of the JAMYB TF. JAMYB is induced by BPH infestation and is transcriptionally regulated by MYC2. Mutations of JAMYB rendered rice plants susceptible to BPH attacks under laboratory and field conditions, indicating that JAMYB positively contributes to BPH resistance. BPH-elicited biosynthesis of phenolamides and volatile compounds was reduced in jamyb mutants compared with wild-type plants. These specialized metabolites, regulated by JAMYB, function as direct and indirect defenses to deter BPH damage or attract parasitoid wasps of BPH eggs. Furthermore, we found that JAMYB directly binds to AC motifs of key phenylpropanoid pathway genes and activates their expression, likely altering the metabolic flux for phenolamide biosynthesis. This study reveals the role of the MYC2-JAMYB module in JA-mediated rice resistance to BPH.
植物对食草动物的防御主要由植物激素茉莉酸（JA）调控。核心的JA信号传导是MYC2转录因子（TF），它调控大量与防御相关基因的表达。然而，水稻中MYC2介导的抗虫性潜在调控机制尚未完全明晰。我们采用褐飞虱（BPH）生物测定、转录激活测定、转录组分析、靶向代谢组学以及靶标切割和标签化测序分析，来研究JAMYB转录因子的生物学功能和调控机制。JAMYB受BPH侵害诱导，并受MYC2转录调控。在实验室和田间条件下，JAMYB突变使水稻植株易受BPH攻击，这表明JAMYB对BPH抗性有正向作用。与野生型植株相比，jamyb突变体中BPH诱导的酚酰胺和挥发性化合物生物合成减少。这些由JAMYB调控的特殊代谢产物，作为直接和间接防御手段，可阻止BPH造成损害或吸引BPH卵的寄生蜂。此外，我们发现JAMYB直接结合关键苯丙烷类途径基因的AC基序并激活其表达，可能改变酚酰胺生物合成的代谢通量。本研究揭示了MYC2-JAMYB模块在JA介导的水稻抗BPH中的作用。
