Department of Energy-Plant Research Laboratory, Michigan State University East Lansing, MI, USA.
Front Plant Sci. 2012 Feb 7;3:19. doi: 10.3389/fpls.2012.00019. eCollection 2012.
The oxylipin hormone jasmonate controls myriad processes involved in plant growth, development, and immune function. The discovery of jasmonoyl-l-isoleucine (JA-Ile) as the major bioactive form of the hormone highlights the need to understand biochemical and cell biological processes underlying JA-Ile homeostasis. Among the major metabolic control points governing the accumulation of JA-Ile in plant tissues are the availability of jasmonic acid, the immediate precursor of JA-Ile, and oxidative enzymes involved in catabolism and deactivation of the hormone. Recent studies indicate that JA-Ile turnover is mediated by a ω-oxidation pathway involving members of the CYP94 family of cytochromes P450. This discovery opens new opportunities to genetically manipulate JA-Ile levels for enhanced resistance to environmental stress, and further highlights ω-oxidation as a conserved pathway for catabolism of lipid-derived signals in plants and animals. Functional characterization of the full complement of CYP94 P450s promises to reveal new pathways for jasmonate metabolism and provide insight into the evolution of oxylipin signaling in land plants.
茉莉酸激素氧化脂素控制着植物生长、发育和免疫功能所涉及的无数过程。茉莉酰基异亮氨酸（JA-Ile）作为激素的主要生物活性形式的发现，突出了需要了解 JA-Ile 动态平衡的生化和细胞生物学过程。在控制 JA-Ile 在植物组织中积累的主要代谢控制点中，有茉莉酸的可用性，茉莉酸是 JA-Ile 的直接前体，以及参与激素分解代谢和失活的氧化酶。最近的研究表明，JA-Ile 的周转是由涉及细胞色素 P450 CYP94 家族成员的 ω-氧化途径介导的。这一发现为通过遗传手段操纵 JA-Ile 水平以增强对环境胁迫的抗性提供了新的机会，并进一步强调 ω-氧化作为植物和动物中脂质衍生信号分解代谢的保守途径。CYP94 P450 全谱的功能特征有望揭示茉莉酸代谢的新途径，并深入了解陆地植物中氧化脂素信号的进化。
