Biochemical and Molecular Investigations of the Transductionof Blue Light Signals in Arabidopsis thaliana

蓝光的光接受在高等植物的发育调控中起着重要作用。蓝光光感受器一方面介导向光的定向生长（向光性），另一方面极快地抑制茎伸长的生长，这是新生幼苗早期去黄化反应的一部分。有强有力的证据表明，这两个过程是通过分离和独立的信号转导途径进行的。本研究的目标是：(1)分离、表征并获得因蓝光照射而磷酸化的质膜蛋白的序列信息，该蛋白似乎与向光性的早期阶段有关；(2)分离、表征并获得与几种针对动物中间丝蛋白的抗体交叉反应的蛋白的序列信息。抑制蛋白一种可能与快速抑制生长有关的蛋白质拟南芥突变体在这两种途径中都是可用的，这使得拟南芥成为这些研究的选择。预计将获得这两个拟南芥蛋白分别参与两种不同蓝光诱导信号转导途径的完整序列信息。蓝光是植物生长发育过程中重要的环境信号。它刺激植物向光生长，并调节幼苗从土壤中冒出时的伸长。这项研究将利用分子遗传学的力量来研究植物对蓝光反应的早期阶段涉及的两种特定蛋白质的结构和作用。这些结果将对我们理解植物对环境反应的分子基础有重要贡献。

Blue light photoreception plays an important role in the regulation of higher plant development. Blue light photoreceptors mediate directional growth toward the light on the one hand (phototropism) and the extremely rapid inhibition of growth of stem elongation that is a part of the early de-etiolation response of emerging seedlings on the other. There is strong evidence that these two processes proceed through separate and independent signal transduction pathways. The goals of this research are: (1) to isolate, characterize, and obtain sequence information on a plasma membrane protein that is phosphorylated as a consequence of blue light irradiation, and that appears to be involved at an early stage in phototropism, and (2) to isolate, characterize, and obtain sequence information on a protein cross-reactive with several antibodies directed against animal intermediate filament proteins, a protein that may be involved in the rapid inhibition of growth. Arabidopsis thaliana mutants are available in both pathways, making Arabidopsis the organism of choice for these studies. It is expected that complete sequence information will be obtained on these two A. thaliana proteins involved respectively in two different blue light-induced signal transduction pathways. %%% Blue light is an important environmental signal in plant growth and development. It stimulates plants to grow toward light and regulates the elongation of young seedlings as they emerge from the soil. This research will take advantage of the power of molecular genetics to study the structure and role of two specific proteins involved in early stages of the response of plants to blue light. The results will be important contributions to our understanding of the molecular basis of plant responses to the environment.