植物的环境信号分子茉莉酸及其生物学功能

Jasmonic acid signaling in plants and its biological functions in relation to environment

茉莉酸信号分子参与植物生长发育众多生理过程的调控,尤其是作为环境信号分子能有效地介导植物对生物及非生物胁迫的防御反应。迄今已知具有信号分子生理功能的至少包括茉莉酸(jasmonic acid,JA)以及茉莉酸甲酯(methyl jasmonate,Me JA)和茉莉酸-异亮氨酸复合物(jasmonoyl-isoleucine,JA-Ile)等茉莉酸衍生物,统称为茉莉酸类化合物(jasmonates,JAs)。从环境信号分子角度介绍了茉莉酸信号的启动(环境信号感知与转导、茉莉酸类化合物合成)、传递(局部传递、维管束传输、空气传播)和生物学功能(茉莉酸信号受体、调控的转录因子、参与的生物学过程)。

Jasmonates( JAs) are fatty acid-derived signaling molecules involved in the regulation of many physiological and developmental processes in plants,including root growth,tuber development,fruit ripening,senescence,tendril coiling,and pollen development. In addition,Jasmonates are important regulators in plant response to biotic and abiotic stresses,such as ozone exposure,wounding,water deficit and pathogen / pest attack. In plants,Jasmonic acid( JA) can be metabolized into different compounds depending on the chemical modification on the carboxylic acid group,pentenyl side chain or the pentanone ring. Currently,JA,Me JA( a volatile methyl ester,methyl jasmonate) and JA-Ile( predominant amino acid conjugate,jasmonoyl-isoleucine) were known to function as signal molecules in plants. Jasmonic acid and its derivatives are collectively named jasmonates. To date,the physiological functions of the jasmonates are still not completely understood. Details of the jasmonate signaling pathway are currently at the center of active research and exciting results have been produced. In this review,we summarize the current status of our knowledge on plant JA signaling pathway and its biological functions in relation to environment,including the triggering of JA signaling,transportation of the JA signals and the biological functions of JA signaling. In general,activation of JA-mediated signaling pathway is accompanied by the regulation of the biosynthesis of JAs. Signaling compounds can be transported via a local response responsible for a short distance signal transduction,translocation through the vascular system or airborne transportation responsible for a long distance signal transduction in plants. In the past few years,lots of new data on JA signaling have been published,and some of the JA signaling components have been identified and functionally analyzed. Our knowledge of JA biosynthesis,metabolism,transportation and plant response has been greatly enhanced. However,there are several major gaps in ourunderstanding of how plants perceive various environmental signals and induce jasmonic acid synthesis. With the development of molecular biology,the discovery and characterization of JA acceptors has paved the way for understanding the core module responsible for JA signaling( COI / JAZ / MYC2). Although we now have a much better understanding of the molecular mechanisms of JA action,many detailed questions remain. For examples,how JA signaling interact with other phytohormones and how plants prioritize growth and development under conditions of environmental stresses. Although JA signaling plays a prominent role in promoting plant defence in plant response to various environmental factors,more and more studies have shown that other phytohormones are also implicated in plant defence signaling pathways,such as salicylic acid( SA),ethylene( ET) and auxin. Cross-talk among multiple signaling pathways is an important mechanism in plant signal transduction networks. However,there is limited knowledge for the complex regulatory networks in relation to plant interaction with the environment. In conclusion,future research needs to focus on the JA perception,mitogen-activated protein kinases( MAPKs) in jasmonic acid signalling,the downstream transcription factors in the JA signaling pathway,the transcription factors regulating plant growth and development,cross-talk among multiple phytohormones signaling pathways,and the diverse actions of JAs in plant growth,development and interaction with the environment.