Taki Nozomi, Sasaki-Sekimoto Yuko, Obayashi Takeshi, Kikuta Akihiro, Kobayashi Koichi, Ainai Takayuki, Yagi Kaori, Sakurai Nozomu, Suzuki Hideyuki, Masuda Tatsuru, Takamiya Ken-Ichiro, Shibata Daisuke, Kobayashi Yuichi, Ohta Hiroyuki
Department of Bioscience, Graduate School of Bioscience and Biotechnology, Tokyo Institute of Technology, 4259 Nagatsuta, Midori-ku, Yokohama 226-8501, Japan.
Plant Physiol. 2005 Nov;139(3):1268-83. doi: 10.1104/pp.105.067058. Epub 2005 Oct 28.
Jasmonic acid (JA) and methyl jasmonate (MeJA), collectively known as JAs, regulate diverse physiological processes in plants, including the response to wounding. Recent reports suggest that a cyclopentenone precursor of JA, 12-oxo-phytodienoic acid (OPDA), can also induce gene expression. However, little is known about the physiological significance of OPDA-dependent gene expression. We used microarray analysis of approximately 21,500 Arabidopsis (Arabidopsis thaliana) genes to compare responses to JA, MeJA, and OPDA treatment. Although many genes responded identically to both OPDA and JAs, we identified a set of genes (OPDA-specific response genes [ORGs]) that specifically responded to OPDA but not to JAs. ORGs primarily encoded signaling components, transcription factors, and stress response-related genes. One-half of the ORGs were induced by wounding. Analysis using mutants deficient in the biosynthesis of JAs revealed that OPDA functions as a signaling molecule in the wounding response. Unlike signaling via JAs, OPDA signaling was CORONATINE INSENSITIVE 1 independent. These results indicate that an OPDA signaling pathway functions independently of JA/MeJA signaling and is required for the wounding response in Arabidopsis.
茉莉酸（JA）和茉莉酸甲酯（MeJA）统称为茉莉素，它们调控植物的多种生理过程，包括对创伤的反应。最近的报道表明，JA的一种环戊烯酮前体，12-氧代-植物二烯酸（OPDA），也能诱导基因表达。然而，关于OPDA依赖性基因表达的生理意义却知之甚少。我们使用对约21500个拟南芥基因的微阵列分析来比较对JA、MeJA和OPDA处理的反应。尽管许多基因对OPDA和茉莉素的反应相同，但我们鉴定出一组基因（OPDA特异性反应基因[ORGs]），它们对OPDA有特异性反应，而对茉莉素没有反应。ORGs主要编码信号成分、转录因子和应激反应相关基因。其中一半的ORGs受创伤诱导。对茉莉素生物合成缺陷突变体的分析表明，OPDA在创伤反应中作为一种信号分子起作用。与通过茉莉素的信号传导不同，OPDA信号传导不依赖于冠菌素不敏感1。这些结果表明，OPDA信号通路独立于JA/MeJA信号通路起作用，并且是拟南芥创伤反应所必需的。
