Light-regulated development in Phytophthora: niche-specific diversification and evolution of the cryptochrome/photolyase superfamily

许多生物利用光、湿度和化学物质等环境信号来调节它们的生长。在微生物中，对这些线索作出反应的一个生物过程是孢子形成。这产生孢子，用于运输到新的地理区域或在不利条件下生存。许多致病微生物也利用孢子感染宿主。该项目将研究环境信号（如光）在产孢过程中的作用，重点关注被称为卵菌的一大类具有重要经济意义的植物病原体。这些物种中的一些在暴露于光下产生孢子，但光抑制其他物种的孢子形成。这个项目将检验一种假设，即孢子形成是由一种特定类型的光感受器蛋白和细胞调节机制的其他成分（如那些激活或抑制基因活性的成分）之间的相互作用所调节的。该项目还将在分子水平上解释为什么不同物种对光的反应不同。这项研究也有可能带来实际回报，因为知道是什么调节了孢子形成，可以导致抑制孢子形成的发展，从而保护作物免受疾病的侵害。该项目将研究与少数民族人口比例高的社区的教育和外展活动结合起来。在疫霉菌（Phytophthora，一种植物致病卵菌属）中，光刺激根病原体的产孢，但抑制叶病原体的产孢。这确保了感染根部的物种的孢子出现在土壤线以上，这样它们就可以传播给新的宿主，而叶面病原体的孢子在夜间出现，以避免干燥或紫外线伤害。这项研究的目的是了解这些对光的不同反应是如何进化的，以根病原体辣椒辣椒和叶病原体病原菌为模型。一个目标是使用RNA-seq来表征光对两个物种基因表达的影响，并确定光诱导启动子中的功能元件。第二个目的是研究隐色素在孢子形成中的作用。这些光感受器蛋白广泛分布于原核生物和真核生物中，并已被证明调节生长、发育和代谢。我们将通过基因沉默、过表达、异源表达和蛋白相互作用研究来研究它们在辣椒辣椒杆菌和大肠杆菌中的功能。在一个属中对光有不同的反应，这为研究一个重要的发育过程的进化提供了一个独特的机会。研究生和本科生将参与这项研究，该研究将与提高学生在STEM领域的成功和兴趣的项目相结合。该奖项反映了美国国家科学基金会的法定使命，并通过使用基金会的知识价值和更广泛的影响审查标准进行评估，被认为值得支持。

Many organisms regulate their growth using environmental signals such as light, humidity, and chemicals. One biological process that is responsive to such cues in microbes is sporulation. This produces spores, which are used for transport to new geographic areas or to survive unfavorable conditions. Many pathogenic microbes also use spores to infect their hosts. This project will examine the role of environmental signals such as light on sporulation, with a focus on a large and economically important group of plant pathogens known as oomycetes. Some of these species make spores upon exposure to light, but light represses spore formation in other species. This project will test the hypothesis that sporulation is regulated by interactions between a specific type of photoreceptor protein and other components of the cell's regulatory machinery, such as those that activate or repress the activity of genes. The project will also explain at a molecular level why different species respond divergently to light. The research also has the potential for a practical return, since knowing what regulates sporulation can lead to the development of inhibitors of sporulation that will protect crops from disease. The project integrates research with education and outreach in communities with high minority demographics.In Phytophthora, a genus of plant pathogenic oomycetes, light stimulates sporulation by root pathogens but represses sporulation by foliar pathogens. This ensures that spores of root-infecting species appear above the soil line so that they can spread to new hosts, and that spores of foliar pathogens appear at night to avoid desiccation or UV damage. The goal of the research is to learn how these divergent responses to light evolved, using the root pathogen P. capsici and the foliar pathogen P. infestans as models. One objective is to use RNA-seq to characterize the effects of light on gene expression in the two species, and identify functional elements within light-induced promoters. A second objective is to study the role of cryptochromes on sporulation. These photoreceptor proteins are distributed widely in prokaryotes and eukaryotes, and have been shown to regulate growth, development, and metabolism. Their function in P. capsici and P. infestans will be examined using gene silencing, overexpression, heterologous expression, and protein-protein interaction studies. Having divergent responses to light within a single genus presents a unique opportunity for studying the evolution of an important developmental process. Graduate and undergraduate students will participate in the research, which will be integrated with programs for increasing student success and interest in STEM fields.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.