Plant fatty acid alpha-dioxygenases (DOXs) catalyze the stereospecific conversion of fatty acids into the corresponding (R)-2-hydroperoxy fatty acids. In several plant species the corresponding gene was shown to be induced by pathogen infection, herbivore attack and environmental stresses. The precise signaling pathway accountable for the induction remains unidentified. In the present study, the effects of bacterial infection, oxidative- and heavy metal-stresses, and plant signaling molecules such as jasmonate, salicylic acid (SA), and ethylene (ET) on expression of a fatty acid alpha-DOX (OsDOX) gene in rice seedlings were investigated. The rice blight bacteria, Xanthomonas oryzae, elicited the accumulation of OsDOX transcripts in the leaves in both the incompatible and compatible interactions. Treating the seedling with CuSO4 also significantly enhanced the OsDOX expression. The degree of induction was shown to be mostly parallel to the level of endogenous jasmonic acid (JA) in the leaves. In contrast, SA was little effective and ET down-regulated not only the OsDOX expression but also the endogenous level of JA in rice seedlings. These results suggested that the OsDOX gene expression by a variety of stress-related stimuli was activated through jasmonate signaling and was negatively regulated by ET.

中文翻译：

---

病原体攻击和重金属胁迫诱导水稻脂肪酸双加氧酶：通过茉莉酸信号激活

植物脂肪酸 α-双加氧酶 (DOX) 催化脂肪酸立体定向转化为相应的 (R)-2-氢过氧脂肪酸。在几个植物物种中，相应的基因被证明是由病原体感染、食草动物攻击和环境压力诱导的。导致诱导的精确信号通路仍未确定。在本研究中，细菌感染、氧化应激和重金属应激以及茉莉酸、水杨酸 (SA) 和乙烯 (ET) 等植物信号分子对脂肪酸 α-DOX (OsDOX) 表达的影响对水稻幼苗基因进行了研究。水稻枯萎病菌米黄单胞菌在不相容和相容的相互作用中都引起了叶片中 OsDOX 转录物的积累。用 CuSO4 处理幼苗也显着增强了 OsDOX 的表达。诱导程度主要与叶片中内源茉莉酸 (JA) 的水平平行。相比之下，SA 几乎没有效果，ET 不仅下调 OsDOX 表达，而且下调水稻幼苗中 JA 的内源水平。这些结果表明 OsDOX 基因表达由各种应激相关刺激通过茉莉酸信号激活，并受到 ET 的负调控。