Regulation of defense signaling in tomato

描述(申请人提供)：多不饱和脂肪酸(PUFAs)的氧化代谢产生一组含氧化合物，称为加氧脂，它调节多细胞生物体的基本生理过程。我们的长期研究目标是了解氧脂合成和代谢的一般原理，并剖析这些生物活性物质调节防御相关过程的分子机制。在目前的应用中，我们将在之前成功建立番茄作为系统诱导对草食性节肢动物抗性的分子遗传分析的模式系统的基础上。这项拟议的研究试图验证一种假设，即脂肪酸衍生的植物激素茉莉酸(JA)是宿主防御反应的细胞间信号，并且JA的生物合成受肽信号系统的调节。该项目的具体目标是：(I)使用基于图谱的方法克隆和鉴定在系统素感知中发挥作用的Sprl基因；(Ii)完成基于图谱的JL1基因的克隆，该基因是JA的环戊烯酮前体12-氧代植物二烯酸的代谢或运输所必需的；(Iii)使用遗传嵌合体来分析JA的生物合成和JA感知在细胞间伤口信号中的作用；以及(Iv)结合生化和功能分析来分析韧皮部分泌物中是否存在JA、系统素和其他诱导防御基因表达的信号。 系统蛋白/JA信号通路为研究多肽和氧磷脂信号协调系统免疫的机制提供了独特的机会。植物中多不饱和脂肪酸氧化代谢的生化途径与花生四烯酸衍生化合物的产生非常相似，花生四烯酸衍生化合物在人类健康和疾病的许多方面发挥着重要作用。因此，这项拟议的研究有望阐明不同生物系统中氧脂代谢的一般原理。这些研究的结果还将提供对脂肪酸衍生信号调节宿主防御反应的具体机制的洞察，以及更广泛地说，多不饱和脂肪酸在健康和患病生物体中的作用。

DESCRIPTION (provided by applicant): Oxidative metabolism of polyunsaturated fatty acids (PUFAs) gives rise to a group of oxygenated compounds, called oxylipins, which regulate essential physiological processes in multicellular organisms. Our long-term research objective is to understand the general principles governing the synthesis and metabolism of oxylipins, and to dissect the molecular mechanisms by which these bioactive substances regulate defense-related processes. In the present application, we will build on our previous success in establishing Lycopersicon esculentum (tomato) as a model system for molecular genetic analysis of systemic induced resistance to herbivorous arthropods. The proposed research seeks to test the hypothesis that the fatty acid-derived plant hormone jasmonic acid (JA) is an intercellular signal for host defense responses, and that the biosynthesis of JA is regulated by the peptide signal systemin. The specific aims of the project are: (i) to use a map-based approach to clone and characterize the Sprl gene that plays a role in systemin perception; (ii) to complete map-based cloning of the JL1 gene that is required for the metabolism or transport of 12-oxo-phytodienoic acid, a cyclopentenone precursor of JA; (iii) to use genetic chimeras to analyze the role of JA biosynthesis and JA perception in intercellular wound signaling; and (iv) to combine biochemical and functional assays to analyze phloem exudate for the presence of JA, systemin, and other signals that induce defense gene expression. The systemin/JA signaling pathway provides a unique opportunity to study the mechanism by which peptide and oxylipin signals coordinate systemic immunity. The biochemical pathways for oxidative metabolism of PUFAs in plants are remarkably similar to those involved in the production of arachidonic acid-derived compounds that play an essential role in numerous aspects of human health and disease. Thus, the proposed research is expected to illuminate general principles of oxylipin metabolism in diverse biological systems. Results obtained from these studies will also provide insight into specific mechanisms by which fatty acid-derived signals regulate host defense responses and, more generally, the role of PUFAs in healthy and diseased organisms.