紫茎泽兰是一种入侵我国的恶性杂草。化感作用是紫茎泽兰种群竞争扩张的一个重要成因，羟基泽兰酮（HHO）是紫茎泽兰的重要化感物质，我们已有的研究表明紫茎泽兰次生代谢途径中酚类代谢的PAL/CHS/F3'H等几个关键酶基因均和羟基泽兰酮高度相关。本项目从肉桂酸四羟化酶（C4H）基因入手，克隆C4H基因并进行表达谱分析；对C4H基因进行过量表达和RNAi干涉的遗传转化，获得转C4H基因的紫茎泽兰植株；对野生型和转基因植株的C4H基因的表达和受HHO诱导下差异分析，对野生型和转基因植株的HHO分离纯化，分析差异。在已有的转PAL/CHS/F3'H基因植株的基础上研究过量表达和RNAi一个基因对其他基因表达的影响，分离纯化酶产物，比较分析不同条件下4个关键节点的基因在酚类代谢途径的关系。探讨C4H基因与HHO的关系，研究该代谢通路在化感物质产生过程中的作用。为揭示紫茎泽兰化感的作用机理提供理论基础。

Eupatorium adenophorum,as a kind of noxious invasive alien weed, has seriously threatened the ecological system of forest and farmland in our country. Allelotaphy is one of important factors in aspect of efficient invasion, and research had showed that HHO is one of important allelochemicals in E.adenophorum.The previous research indicated that some genes in phenolic metabolic pathway of E.adenophorum, such as phenylalanine ammonia-lyase(PAL) gene, chalcone synthase gene, flavonoid 3'-hydroxylase gene and so on, were closely related to HHO. In this project, cinnamate-4-hydroxylase gene was cloned, we will further analyse the expression profile of this gene. We are also plan to overexpress or scilence the gene in E.adenophorum. Comparing with the wild type plant,quantitative RT-PCR will be used to analyze the expression difference of gene when the plant is induced by HHO in trangenic plant. We have obtained some transgenic plant of phenylalanine ammonia-lyase gene, chalcone synthase gene and flavonoid 3'-hydroxylase gene. Based on this work, we will study the effect of a gene to other genes when this gene is overexpressed or scilenced in the plant, we also need to separate and purify the product of cinnamate-4-hydroxylase and investigate the difference of the product in the yield. Ultimately, we will detect the relationship of phenolic metabolic pathway among these four key genes, and discuss the relationship between HHO and these four genes. Reveal the function of phenolic metabolic pathway in the generating process of allelochemical, will provide the theory basis in studying the mechanism of allelopathy in E. adenophorum.