Nitrogen-dependent regulation of secondary metabolism in Ustilago maydis

玉米黑粉菌次生代谢的氮依赖性调控

• 批准号: 70346709
• 负责人: Professor Dr. Michael Bölker
• 金额: --
• 依托单位: Arbeitsgruppe Genetik
• 依托单位国家: 德国
• 项目类别: Research Grants
• 财政年份: 2008
• 资助国家: 德国
• 起止时间: 2007-12-31 至 2012-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/70346709?language=en
• 关键词: Nitrogen; dependent; regulation; secondary; metabolism

Many microorganisms respond to conditions of nutrient limitation with the secretion of amphipathic secondary metabolites. These substances act as biosurfactants and enhance attachment of microorganisms to hydrophobic surfaces, increase the bioavailability of water-insoluble nutrients and often display antibiotic activity. Here we use the dimorphic phytopathogenic fungus Ustilago maydis to study the nitrogendependent regulation of two glycolipid biosynthetic gene clusters. The large ustilagic acid (UA) gene cluster contains a regulatory gene encoding a potential zinc finger domain protein, which is critical for the production of this secondary metabolite. Expression of this putative transcription factor is both necessary and sufficient for the induction of all UA biosynthetic cluster genes. The mannosylerythritol lipid (MEL) biosynthetic gene cluster is also induced by nitrogen limitation, but does not contain a specific transcription factor. Interestingly, expression of this gene cluster is also affected by transcriptional regulators that control mating and pathogenicity in U. maydis. We will combine molecular and genomic approaches to characterize promoters and transcription factors involved in the nitrogen-dependent regulation of these biosurfactant biosynthetic gene clusters. The longterm goal of this project is the elucidation of the molecular mechanisms operating in the environmental control of secondary metabolism in U. maydis.

许多微生物通过分泌两亲性次生代谢物来应对营养限制条件。这些物质充当生物表面活性剂，增强微生物对疏水表面的附着，增加水不溶性营养物质的生物利用度，并且通常表现出抗生素活性。在这里，我们使用二态性植物病原真菌玉米黑粉菌来研究两个糖脂生物合成基因簇的氮依赖性调节。大乌冬酸 (UA) 基因簇包含一个编码潜在锌指结构域蛋白的调节基因，该蛋白对于这种次级代谢产物的产生至关重要。该假定转录因子的表达对于所有 UA 生物合成簇基因的诱导都是必要且充分的。甘露糖赤藓糖醇脂质（MEL）生物合成基因簇也是由氮限制诱导的，但不包含特定的转录因子。有趣的是，该基因簇的表达也受到控制玉米交配和致病性的转录调节因子的影响。我们将结合分子和基因组方法来表征这些生物表面活性剂生物合成基因簇的氮依赖性调节所涉及的启动子和转录因子。该项目的长期目标是阐明玉米次级代谢环境控制的分子机制。