Genomic Studies of Blue-Light Signaling Pathways Controlling Seedling Growth

对植物感知和响应光环境的机制的详细描述对于全面了解植物的发育是必要的，这对于那些关注植物在农业和生物技术中的实际应用的人以及学术研究人员来说是重要的。在缺乏隐花红光感受器的拟南芥突变体中，控制蓝光下幼苗生长的过程不能正常工作。了解导致野生型和隐色素突变体幼苗生长速度差异的分子水平差异将有助于更好地理解是什么控制了植物生长的基本过程。该奖项提供的资金将使人们能够使用DNA微阵列技术在苗木对光的反应过程中的某个时间点同时测量数千个基因的表达水平，这一点之前的工作已经证明是至关重要的。那些被发现在表达上不同的基因将被操纵，以检验它们在生长控制中发挥作用的假设。寻找在特定光照条件下影响幼苗生长速度的基因，可以为植物育种者和生物技术专家提供有希望的研究目标。除了这种基因组方法，还将测试关于激素赤霉酸在蓝光控制生长现象中所起作用的具体假设。此外，将使用细胞生物学技术来研究钙在反应的最早阶段的作用，这是由趋光素1光感受器介导的。实验设计的一个中心主题是，对正在研究的生物学的详细理解应该指导基因组学实验，其结果应该带回生物系统进行验证。然后这个循环就可以重复了。以这种迭代的方式，在下一个资金周期中，可以获得关于光如何控制生长的非常详细的、分子水平的描述。在此过程中，本科生、研究生和博士后将接受现代生物学研究方面的培训，这将增加国家的科学基础设施。

A detailed description of the mechanisms plants use to sense and respond to their light environment is necessary for a complete understanding of plant development, which is important to those concerned with the practical uses of plants in agriculture and biotechnology as well as to academic researchers. The processes that control the growth of seedlings exposed to blue light do not function properly in Arabidopsis thaliana mutants that lack the cryptochrome photoreceptors. Understanding the molecular-level differences responsible for the differences in growth rates between the wild-type and cryptochrome mutant seedlings will lead to a better understanding of what controls the fundamental process of plant growth. The funding provided by this award will enable measurements of the expression levels of thousands of genes at once using DNA microarray technology at a point during the seedling's response to light that previous work has shown to be critical. Those genes found to differ in expression will be manipulated to test the hypothesis that they function in growth control. Finding genes that affect the rate of seedling growth in specific light conditions could provide plant breeders and biotechnologists with promising targets for their studies. In addition to such a genomic approach, specific hypotheses about the role of the hormone gibberellic acid in the phenomenon of blue-light controlled growth will be tested. Also, the role of calcium in the earliest phase of the response, which is mediated by the phototropin 1 photoreceptor, will be investigated using cell biological techniques.A central theme in the experimental design is that a detailed understanding of the biology under study should guide the genomics experiments, the results of which should be brought back to the biological system for validation. The cycle can then be repeated. In this iterative fashion, a very detailed, molecular-level description of how light controls growth can be obtained during the next funding cycle. In the process, undergraduate, graduate, and postdoctoral students will receive training in modern biological research, which adds to the country's scientific infrastructure.