Weber H, Vick B A, Farmer E E
Institute de Biologie et de Physiologie Végétales, Université de Lausanne, Bâtiment de Biologie, 1015 Lausanne, Switzerland.
Proc Natl Acad Sci U S A. 1997 Sep 16;94(19):10473-8. doi: 10.1073/pnas.94.19.10473.
Jasmonic acid and its precursors are potent regulatory molecules in plants. We devised a method for the simultaneous extraction of these compounds from plant leaves to quantitate changes in the levels of jasmonate family members during health and on wounding. During our study, we identified a novel 16-carbon cyclopentenoic acid in leaf extracts from Arabidopsis and potato. The new compound, a member of the jasmonate family of signals, was named dinor-oxo-phytodienoic acid. Dinor-oxo-phytodienoic acid was not detected in the Arabidopsis mutant fad5, which is incapable of synthesizing 7Z,10Z, 13Z-hexadecatrienoic acid (16:3), suggesting that the metabolite is derived directly from plastid 16:3 rather than by beta-oxidation of the 18-carbon 12-oxo-phytodienoic acid. Simultaneous quantitation of jasmonate family members in healthy leaves of Arabidopsis and potato suggest that different plant species have different relative levels of jasmonic acid, oxo-phytodienoic acid, and dinor-oxo-phytodienoic acid. We term these profiles "oxylipin signatures." Dinor-oxo-phytodienoic acid levels increased dramatically in Arabidopsis and potato leaves on wounding, suggesting roles in wound signaling. Treatment of Arabidopsis with micromolar levels of dinor-oxo-phytodienoic acid increased the ability of leaf extracts to transform linoleic acid into the alpha-ketol 13-hydroxy-12-oxo-9(Z) octadecenoic acid indicating that the compound can regulate part of its own biosynthetic pathway. Tightly regulated changes in the relative levels of biologically active jasmonates may permit sensitive control over metabolic, developmental, and defensive processes in plants.
茉莉酸及其前体是植物中重要的调节分子。我们设计了一种从植物叶片中同时提取这些化合物的方法，以定量健康状态和受伤时茉莉酸家族成员水平的变化。在我们的研究过程中，我们在拟南芥和马铃薯的叶片提取物中鉴定出一种新型的16碳环戊烯酸。这种新化合物是信号茉莉酸家族的成员，被命名为去甲-氧代-植物二烯酸。在无法合成7Z,10Z,13Z-十六碳三烯酸（16:3）的拟南芥突变体fad5中未检测到去甲-氧代-植物二烯酸，这表明该代谢产物直接来源于质体16:3，而非18碳的12-氧代-植物二烯酸的β-氧化。对拟南芥和马铃薯健康叶片中茉莉酸家族成员的同时定量分析表明，不同植物物种中茉莉酸、氧代-植物二烯酸和去甲-氧代-植物二烯酸的相对水平不同。我们将这些谱型称为“氧脂素特征”。在受伤时，拟南芥和马铃薯叶片中的去甲-氧代-植物二烯酸水平显著增加，表明其在伤口信号传导中发挥作用。用微摩尔水平的去甲-氧代-植物二烯酸处理拟南芥，可提高叶片提取物将亚油酸转化为α-酮醇13-羟基-12-氧代-9(Z)-十八碳烯酸的能力，这表明该化合物可以调节其自身生物合成途径的一部分。生物活性茉莉酸相对水平的严格调控变化可能允许对植物的代谢、发育和防御过程进行灵敏控制。
