活性氧在竹黄菌发育分化及竹红菌素合成中的调控作用研究

项目名称： 活性氧在竹黄菌发育分化及竹红菌素合成中的调控作用研究

项目编号： No.81473183

项目类型： 面上项目

立项/批准年度： 2015

项目学科： 医药、卫生

项目作者： 王剑文

作者单位： 苏州大学

项目金额： 70万元

中文摘要： 竹红菌素是从竹黄菌（Shiraia bambusicola）中分离发现的新型光敏药物，竹红菌素光敏化产生的活性氧是导致其生物活性的重要因素。活性氧又被誉为细胞生命活动的第二信使，探讨活性氧对竹黄菌自身发育分化与竹红菌素合成的调节作用，对了解微生物生命活动中活性氧信号作用与光敏性物质合成具有重要的理论意义和应用价值。我们以课题组筛选和选育的竹黄菌为对象，通过光/暗周期诱导考察竹黄菌中活性氧产生来源与种类；外施活性氧供体（H2O2,甲萘醌）、抗氧化剂或NADPH氧化酶及葡萄糖氧化酶抑制剂探讨活性氧对孢子萌发、菌丝生长、微核与子座形成的作用；通过活性氧细胞信号转导以及对竹红菌素合成的影响，利用cDNA-AFLP进行基因差异表达分析，获得竹黄菌中对活性氧有响应的菌丝分化和竹红菌素合成特异酶基因；建立竹黄子座人工培育与竹红菌素发酵生产的诱导调节方法，为竹红菌素等真菌光敏药物的生产提供理论基础和参考。

中文关键词： 竹黄菌；竹红菌素；活性氧；菌丝分化；生物合成

英文摘要： Hypocrellins, naturally occurring perylene quinones isolated from a parasitic fungus Shiraia bambusicola, are new type of non-porphyrin photodynamic agents. High quantum yield of reactive oxygen species (ROS) released by their photochemical reactions is responsible for their photoxicity and anticancer activity. Although ROS are recognized as a second message in the life activity of plant and mammalian cells, there are less reports on ROS role on microbes themselves. It is of scientific significances to explore the impact of endogenous ROS on fungal differentiation and hypocrellin biosynthesis. Under the dark and light conditions we will observe ROS burst and explore the kinds of free radicals produced by photochemical reaction or catalyzed by endogenous enzymes such as NADPH oxidase (NOX) and glucose oxidase (GOX). With the treatment of ROS donor (H2O2, menadione), antioxidants (Vitamin C or E) and inhibitors of NOX or GOX, the ROS regulation on fungal differentiation from initiation of conidation, mycelium growth to sclerotia phase and stroma formation will be revealed. The MAPK signaling cascade and cell apoptosis induced by ROS will send the regulation messenger on key enzymes in the pathway of hypocrellin biosynthesis. The differential gene expression by cDNA-AFLP analysis and the characterization of some enzymes responding to ROS signal will be obtained. The methods for stroma cultivation and anamorphosis fermentation will be established for higher hypocrellin yields. We believe our ongoing results will be helpful in the application of ROS regulation on agricultural and biotechnological production hypocrellin and more new photosensitivity perylenequinones. Our research will give hints or theoretical basis of ROS modulation on production of fungal-derived drugs for photodynamic therapy.

英文关键词： Shiraia bambusicola;hypocrellin;reactive oxygen species;fungal differentiation;biosynthesis