Role of Arabidopsis SFD1 in Systemic Acquired Resistance

系统获得性抗性是植物体内的一种诱导防御机制，可增强对多种病原菌的抗性。SAR的激活需要一种未知因子通过韧皮部的转运。拟南芥SFD1基因编码二羟丙酮磷酸(DHAP)还原酶，是合成孔径雷达所必需的。DHAP还原酶催化DHAP和甘油-3-磷酸的相互转化，为甘油脂的生物合成提供甘油骨架。在sfd1突变体中，脂质代谢发生了改变，提示脂质(S)在SAR中起着重要作用。这项建议的长期目标是研究SFD1在SAR中的作用，从而验证上述假说。为了实现这些目标，将采用遗传、分子和生化方法相结合的方法来表征SFD1的生化功能。此外，SFD1衍生因子在韧皮部激活过程中的作用将通过一种新的生物测定和高灵敏的质谱学方法相结合来解决。所提出的研究将对理解合成孔径雷达中的长距离信号有很大的帮助。该项目将提供一个极好的机会，通过将当前关于脂肪代谢和植物胁迫反应的遗传、分子和生物化学基础的知识带入课堂，将最先进的研究和教育结合起来。除了为研究生和博士后研究员提供培训外，该项目还将使本科生参与生物科学的研究，并扩大代表性不足群体的参与。特别是，每年夏天将招募一名来自非授予博士学位的机构的本科生参与该项目。这个项目的结果将对整个社会产生潜在的好处。这项研究确定的脂质(S)可能为增强植物的抗病能力提供新的靶点，从而限制有毒化学物质的使用来保护植物，从而改善我们的环境质量和健康。

Systemic acquired resistance is an inducible defense mechanism in plants that confers enhanced resistance against a broad-spectrum of pathogens. The activation of SAR requires the translocation of an unknown factor through the phloem. The Arabidopsis thaliana SFD1 gene, which encodes a dihydroxyacetone phosphate (DHAP) reductase, is required for SAR. DHAP reductases catalyze the interconversion of DHAP and glycerol-3-phosphate, which provides the glycerol backbone for glycerolipid biosynthesis. Lipid metabolism is altered in the sfd1 mutant, suggesting that a lipid(s) has an important role in SAR. The long-term objectives of this proposal are to study the role of SFD1 in SAR, thereby testing the above hypothesis. To achieve these objectives, a combination of genetic, molecular and biochemical approaches will be pursued to characterize the biochemical function of SFD1. In addition, the role of a SFD1-derived factor in the phloem during the activation of SAR will be addressed with a novel bioassay in combination with highly sensitive mass-spectrometric approaches. The proposed research will contribute greatly to the understanding of long-distance signaling in SAR. The project will provide an excellent opportunity to integrate state-of-the-art research and education by bringing current knowledge of lipid metabolism and the genetic, molecular and biochemical basis of plant stress responses into the classroom. In addition to providing training to graduate students and post doctoral fellows, this project will engage undergraduates in research in the biological sciences and broaden the participation of underrepresented groups. In particular, an undergraduate student from a non-Ph.D.-granting institution will be recruited to work on the project each summer. Results from this project will have potential benefits to society at large. The lipid(s) identified by the proposed study could provide new targets for enhancing disease resistance in plants, thus limiting the utilization of toxic chemicals to protect plants, thereby improving the quality of our environment and health.