THE MOLECULAR BASIS OF PLANT DEFENSE AGAINST UV RADIATION

我们并不完全了解帮助保护 人类对抗紫外线。我们目前在这一领域的大部分知识都是 源自对细菌和酵母的研究。这样做的总体目的是 该项目是使用拟南芥植物作为模式系统，以增加我们的 对植物适应性反应的分子基础的理解 生物系统对紫外线胁迫的反应。这种有机体的选择是基于 关于它是服从于分子和经典遗传学研究的。 总体计划是找到并分离与保护性基因有关的基因 对紫外线辐射的反应；分析这些基因并研究它们的 功能，以确定它们在抗紫外线中所起的作用；以及 最终要研究它们在体内表达的调控机制 对紫外线辐射的反应。正在采取的方法有两个方面：1. 分离和分析对紫外线辐射抗性发生变化的突变体； 和2.直接获得被激活的基因克隆 对紫外线辐射的反应。已经发现了一种突变体，它显示出一种剧烈的 增加对紫外线辐射的敏感度，因为 各种吸收紫外线的类黄酮类物质的积累。具体地说，目标是 是让MBR学生在这两种方法中都参与进来， 根据他们的兴趣、技能和职业目标， 以下项目：1.确定紫外线吸收的身份 紫外线敏感突变体中缺失的类黄酮类化合物。2.确定 类黄酮类生物合成途径中的哪些酶活性 阻挡在变种人身上。3.将受影响的基因定位到一个 特定的染色体位置。4.分析不同的参数 控制紫外线诱导的类黄酮水平的增加，特别是在 紫外光信号的质量。5.开始第二种方法来定义 其他耐紫外线基因。因为我的拉美裔背景，经历， 和科学兴趣，我觉得我可以有效地引导和激励 少数族裔学生认真参与研究；成功 完成他们的项目，并认真考虑在 生物医学研究。

We do not fully understand the molecular mechanisms that help protect humans against UV. Much of our current knowledge in this area has been derived from studies in bacteria and yeast. The general aim of this project is to use the plant Arabidopsis as a model system to increase our understanding of the molecular basis of the adaptive responses of biological systems towards UV-stress. The choice of this organism is based on its being amenable to molecular as well as classical genetics studies. The overall plan is to find and isolate genes involved in the protective responses against UV-radiation; to analyze these genes and study their function in order to determine the role they play in UV-resistance; and ultimately to investigate the mechanisms that modulate their expression in response to UV-radiation. The approach being taken is two fold: 1. To isolate and analyze mutants displaying altered resistance to UV-radiation; and 2. To directly obtain clones of genes that become activated in response to UV-radiation. A mutant has been found which shows a drastic increase in sensitivity to UV-radiation because of a block in the accumulation of various UV-absorbing flavonoids. Specifically, the goals are to engage MBRS students in both approaches by assigning them, according to their interests, skills and career goals, to one of the following projects: 1. To determine the identity of the UV-absorbing flavonoids which are missing in the UV-sensitive mutant. 2. To determine which enzymatic activity in the flavonoid biosynthetic pathway has been blocked in the mutant. 3. To genetically map the affected gene to a specific chromosomal location. 4. To analyze the different parameters that govern the UV-induced increase in flavonoid levels, especially with regard to the quality of the UV-signal. 5. To begin the second approach to define other UV-tolerance genes. Because of my Hispanic background, experience, and scientific interests, I feel I can efficiently guide and motivate minority students to become seriously involved in research; successfully complete their project and seriously consider pursuing a career in biomedical research.