State Key Laboratory of Rice Biology and Breeding, Key Laboratory of Biology of Crop Pathogens and Insects of Zhejiang Province, Institute of Insect Sciences, Zhejiang University, Hangzhou 310058, China.
Zhejiang Academy of Agricultural Sciences, Institute of Virology and Biotechnology, 310021 Hangzhou, China.
Plant Cell. 2024 Sep 3;36(9):3362-3377. doi: 10.1093/plcell/koae159.
The phytohormone jasmonate (JA) plays a central role in plant defenses against biotic stressors. However, our knowledge of the JA signaling pathway in rice (Oryza sativa) remains incomplete. Here, we integrated multiomic data from three tissues to characterize the functional modules involved in organizing JA-responsive genes. In the core regulatory sector, MYC2 transcription factor transcriptional cascades are conserved in different species but with distinct regulators (e.g. bHLH6 in rice), in which genes are early expressed across all tissues. In the feedback sector, MYC2 also regulates the expression of JA repressor and catabolic genes, providing negative feedback that truncates the duration of JA responses. For example, the MYC2-regulated NAC (NAM, ATAF1/2, and CUC2) transcription factor genes NAC1, NAC3, and NAC4 encode proteins that repress JA signaling and herbivore resistance. In the tissue-specific sector, many late-expressed genes are associated with the biosynthesis of specialized metabolites that mediate particular defensive functions. For example, the terpene synthase gene TPS35 is specifically induced in the leaf sheath and TPS35 functions in defense against oviposition by brown planthoppers and the attraction of this herbivore's natural enemies. Thus, by characterizing core, tissue-specific, and feedback sectors of JA-elicited defense responses, this work provides a valuable resource for future discoveries of key JA components in this important crop.
植物激素茉莉酸（JA）在植物抵御生物胁迫方面起着核心作用。然而，我们对水稻（Oryza sativa）中 JA 信号通路的了解仍不完整。在这里，我们整合了来自三种组织的多组学数据，以描述参与组织 JA 响应基因的功能模块。在核心调控区，MYC2 转录因子转录级联在不同物种中是保守的，但具有不同的调节剂（例如水稻中的 bHLH6），其中基因在所有组织中都早期表达。在反馈区，MYC2 还调节 JA 抑制剂和分解代谢基因的表达，提供负反馈，缩短 JA 反应的持续时间。例如，MYC2 调节的 NAC（NAM、ATAF1/2 和 CUC2）转录因子基因 NAC1、NAC3 和 NAC4 编码抑制 JA 信号和植食性昆虫抗性的蛋白质。在组织特异性区，许多晚期表达的基因与专门代谢物的生物合成有关，这些代谢物介导特定的防御功能。例如，萜烯合酶基因 TPS35 在叶鞘中特异性诱导，TPS35 可防御褐飞虱产卵并吸引这种植食性昆虫的天敌。因此，通过描述 JA 诱导防御反应的核心、组织特异性和反馈区，这项工作为未来在这一重要作物中发现关键 JA 成分提供了有价值的资源。
