Department of Plant Molecular Genetics, Centro Nacional de Biotecnología, Consejo Superior de Investigaciones Científicas, Madrid 28049, Spain.
Facultad de Ciencia y Tecnología, Universidad de La Rioja, Logroño (La Rioja) 26006, Spain.
Proc Natl Acad Sci U S A. 2022 Sep 6;119(36):e2202930119. doi: 10.1073/pnas.2202930119. Epub 2022 Aug 29.
In plants, jasmonate signaling regulates a wide range of processes from growth and development to defense responses and thermotolerance. Jasmonates, such as jasmonic acid (JA), (+)-7--jasmonoyl-l-isoleucine (JA-Ile), 12-oxo-10,15()-phytodienoic acid (OPDA), and dinor-12-oxo-10,15()-phytodienoic acid (dn-OPDA), are derived from C18 (18 Carbon atoms) and C16 polyunsaturated fatty acids (PUFAs), which are found ubiquitously in the plant kingdom. Bryophytes are also rich in C20 and C22 long-chain polyunsaturated fatty acids (LCPUFAs), which are found only at low levels in some vascular plants but are abundant in organisms of other kingdoms, including animals. The existence of bioactive jasmonates derived from LCPUFAs is currently unknown. Here, we describe the identification of an OPDA-like molecule derived from a C20 fatty acid (FA) in the liverwort (Mp), which we term (5,8)-10-(4-oxo-5-(()-pent-2-en-1-yl)cyclopent-2-en-1-yl)deca-5,8-dienoic acid (C20-OPDA). This molecule accumulates upon wounding and, when applied exogenously, can activate known Coronatine Insensitive 1 (COI1) -dependent and -independent jasmonate responses. Furthermore, we identify a dn-OPDA-like molecule (Δ-dn-OPDA) deriving from C20-OPDA and demonstrate it to be a ligand of the jasmonate coreceptor (MpCOI1-Mp Jasmonate-Zinc finger inflorescence meristem domain [MpJAZ]) in . By analyzing mutants impaired in the production of LCPUFAs, we elucidate the major biosynthetic pathway of C20-OPDA and Δ-dn-OPDA. Moreover, using a double mutant compromised in the production of both Δ-dn-OPDA and dn-OPDA, we demonstrate the additive nature of these molecules in the activation of jasmonate responses. Taken together, our data identify a ligand of MpCOI1 and demonstrate LCPUFAs as a source of bioactive jasmonates that are essential to the immune response of .
在植物中，茉莉酸信号调节着从生长发育到防御反应和耐热性等广泛的过程。茉莉酸（JA）、（+）-7--茉莉酰基-l-异亮氨酸（JA-Ile）、12-氧代-10,15()-植二烯酸（OPDA）和二降-12-氧代-10,15()-植二烯酸（dn-OPDA）等茉莉酸类物质来源于 C18（18 个碳原子）和 C16 多不饱和脂肪酸（PUFAs），这些物质在植物界中广泛存在。苔藓植物也富含 C20 和 C22 长链多不饱和脂肪酸（LCPUFAs），这些物质在一些维管植物中含量很低，但在其他生物界（包括动物）中含量丰富。目前还不知道是否存在来源于 LCPUFAs 的生物活性茉莉酸类物质。在这里，我们描述了在叶苔（Mp）中鉴定出一种源自 C20 脂肪酸（FA）的 OPDA 样分子，我们将其命名为（5,8）-10-（4-氧代-5-（()-戊-2-烯-1-基）环戊-2-烯-1-基）癸-5,8-二烯酸（C20-OPDA）。这种分子在受伤时会积累，当外源性施加时，能激活已知的冠状素不敏感 1（COI1）依赖和非依赖的茉莉酸反应。此外，我们鉴定出一种源自 C20-OPDA 的 dn-OPDA 样分子（Δ-dn-OPDA），并证明它是茉莉酸核心受体（MpCOI1-Mp 茉莉酸-锌指花序分生组织域[MpJAZ]）在 中的配体。通过分析在 LCPUFAs 产生中受损的突变体，我们阐明了 C20-OPDA 和 Δ-dn-OPDA 的主要生物合成途径。此外，利用在 Δ-dn-OPDA 和 dn-OPDA 产生方面都有缺陷的双突变体，我们证明了这些分子在激活茉莉酸反应中的加性性质。总之，我们的数据鉴定了 MpCOI1 的配体，并证明了 LCPUFAs 是生物活性茉莉酸的来源，这些茉莉酸对 的免疫反应至关重要。
