Analysis of the Role of pH Regulation in the Secretion of Proteins and the Virulence of the Apoplast-Infecting Fungus Mycosphaerella Graminicola

感染植物的真菌既是一种经济威胁，也是研究基本生物过程的有用系统。一些真菌植物病原菌使用的一种简单的侵染方式是侵染叶细胞之间的间隙，即质外体。尽管感染机制并不复杂，但这些真菌如何能够进入宿主、躲避检测和获得营养，这些事件共同构成了发病机制，仍有许多问题没有得到解答。本项目的具体目的是确定环境pH信号在小麦质外体侵染真菌(Mycosphaerella Graminicola)的发病机制中所起的作用。禾谷分枝杆菌是一种很好的病原菌，因为它在培养物中表现出两种可能的生长类型(单细胞和丝状)，在其植物宿主中表现出两种不同的生长阶段(生物营养(植物细胞不受损害)和坏死营养(植物细胞受到损害)，并具有测序的基因组。缺乏pH信号级联成分的突变真菌将被创造出来，并根据在不同pH条件下和植物寄主中的生长情况进行评估。该项目将依靠分子、生化和遗传方法。因此，人们将了解pH值在影响感染过程中所起的作用，以及禾谷分枝杆菌如何感知pH值。该项目应该提供有关这种真菌中一种新的信号机制的信息，该机制可能更广泛地适用于其他真菌植物病原体。这项工作的更广泛影响还包括为劳伦斯理工大学的本科生提供研究经验。

Fungi which infect plants represent both an economic threat and a useful system for the study of fundamental biologic processes. One simple mode of infection used by some fungal plant pathogens is the infection of the space between the cells of the leaf, the apoplast. Even though the infection mechanism is not complex, there are many questions which remain unanswered about how these fungi are able to enter the host, avoid detection, and gain nutrients, events which together comprise pathogenesis. The specific aim of this project is to determine the role that ambient pH signaling plays in the pathogenesis of an apoplast-infecting fungus (Mycosphaerella graminicola) on wheat. M. graminicola is an excellent pathogen for investigation because it exhibits two possible types of growth in culture (single celled and filamentous), two different phases of growth in its plant host (biotrophic (where plant cells are not damaged) and necrotrophic (where plant cells are damaged) and has a sequenced genome. Mutant fungi which lack components of the pH signaling cascade will be created and evaluated with respect to growth under various pH conditions and in plant hosts. The project will rely upon molecular, biochemical and genetic approaches. As a result, the role that pH is playing in influencing the infection process and how pH is sensed by M. graminicola will be understood. The project should provide information about a novel signaling mechanism in this fungus which may be more broadly applicable to other fungal plant pathogens. The broader impacts of this work also include providing research experiences for undergraduate students at Lawrence Technological University.