Plant Cytochrome P-450: Regulation of Gene Expression

本研究的目的是分离和鉴定豌豆幼苗中编码反式肉桂酸羟基酶的完整基因和基因，并通过克隆和全序列分析在核苷酸水平上鉴定分离到的基因(S)及其邻近的调控区；并对植物微粒体P-450的免疫学水平进行了鉴定。这项研究的总体目标是阐明植物组织中基因表达调控的分子机制，近期目标集中在植物王国中普遍存在的细胞色素P-450单加氧酶系统上。这些酶在植物外源物质的解毒、植物激素的生物合成以及木质素、萜类、黄酮类和酚酸合成的关键中间体的产生中起着至关重要的作用。一些细胞色素P-450单加氧酶的从头合成似乎受到光和各种合成生长素和除草剂的调节。控制P-450介导的这些化合物的代谢可能导致与生理相关的除草剂抗性和植物激素调节事件。通过这些研究阐明的调控过程的许多一般特征将普遍应用于植物基因表达的其他机制问题。

The aims of this research are to isolate and characterize intact cDNAs and genes coding for trans- cinnamic acid hydroxylase in pea seedlings; to characterize, at the nucleotide level, the isolated gene(s) and the adjacent regulatory regions through cloning and complete sequence analysis; and to characterize the immunological level of the plant microsomal P-450s.%%% The broad, overall goal of the proposed research is to elucidate the molecular mechanisms for the regulation and control of gene expression in plant tissue, focusing the near term objectives on the cytochrome P-450 monoxygenase systems found ubiquitously in the plant kingdom. These enzymes play paramount roles in the detoxification of plant xenobiotics, in the biosynthesis of plant hormones, and in the production of key intermediates in the synthesis of lignins, terpenes, flavonoids and phenolic acids. The de novo synthesis of some cytochrome P-450 monoxygenases appear to be regulated by light and by the administration of a variety of synthetic auxins and herbicides. Control over the P-450 mediated metabolism of these compounds could lead to physiologically relevant herbicide resistance and plant hormone regulation events. Many general features of the regulatory processes elucidated through these studies will have general application to other mechanistic questions in plant gene expression.***//