Rodrigues Maria A, Bianchetti Ricardo E, Freschi Luciano
Laboratory of Plant Physiology, Institute of Biosciences, Department of Botany, University of São Paulo , São Paulo, Brazil.
Front Plant Sci. 2014 Dec 1;5:665. doi: 10.3389/fpls.2014.00665. eCollection 2014.
Ethylene metabolism in higher plants is regulated by a wide array of endogenous and environmental factors. During most physiological processes, ethylene levels are mainly determined by a strict control of the rate-limiting biosynthetic steps responsible for the production of 1-aminocyclopropane-1-carboxylic acid (ACC) and its subsequent conversion to ethylene. Responsible for these reactions, the key enzymes ACC synthase and ACC oxidase are encoded by multigene families formed by members that can be differentially regulated at the transcription and post-translational levels by specific developmental and environmental signals. Among the wide variety of environmental cues controlling plant ethylene production, light quality, duration, and intensity have consistently been demonstrated to influence the metabolism of this plant hormone in diverse plant tissues, organs, and species. Although still not completely elucidated, the mechanisms underlying the interaction between light signal transduction and ethylene evolution appears to involve a complex network that includes central transcription factors connecting multiple signaling pathways, which can be reciprocally modulated by ethylene itself, other phytohormones, and specific light wavelengths. Accumulating evidence has indicated particular photoreceptors as essential mediators in light-induced signaling cascades affecting ethylene levels. Therefore, this review specifically focuses on discussing the current knowledge of the potential molecular mechanisms implicated in the light-induced responses affecting ethylene metabolism during the regulation of developmental and metabolic plant responses. Besides presenting the state of the art in this research field, some overlooked mechanisms and future directions to elucidate the exact nature of the light-ethylene interplay in higher plants will also be compiled and discussed.
高等植物中的乙烯代谢受多种内源性和环境因素的调节。在大多数生理过程中，乙烯水平主要通过严格控制负责1-氨基环丙烷-1-羧酸（ACC）生成及其随后转化为乙烯的限速生物合成步骤来确定。负责这些反应的关键酶ACC合酶和ACC氧化酶由多基因家族编码，这些家族的成员可通过特定的发育和环境信号在转录和翻译后水平受到差异调节。在控制植物乙烯产生的多种环境线索中，光质、持续时间和强度一直被证明会影响这种植物激素在不同植物组织、器官和物种中的代谢。尽管其机制仍未完全阐明，但光信号转导与乙烯生成之间相互作用的潜在机制似乎涉及一个复杂的网络，其中包括连接多个信号通路的核心转录因子，这些转录因子可被乙烯本身、其他植物激素和特定光波长相互调节。越来越多的证据表明，特定的光感受器是影响乙烯水平的光诱导信号级联反应中的重要介质。因此，本综述特别侧重于讨论在调节植物发育和代谢反应过程中，影响乙烯代谢的光诱导反应所涉及的潜在分子机制的现有知识。除了介绍该研究领域的现状外，还将汇编和讨论一些被忽视的机制以及阐明高等植物中光与乙烯相互作用确切性质的未来方向。
