Investigating control of Ustilago maydis teliospore formation, dormancy and germination

研究玉米黑粉菌冬孢子形成、休眠和萌发的控制

• 批准号: RGPIN-2019-06029
• 负责人: Saville, Barry
• 金额: $ 3.42万
• 依托单位: Trent University
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2020
• 资助国家: 加拿大
• 起止时间: 2020-01-01 至 2021-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=715909
• 关键词: Investigating; control; Ustilago; maydis; teliospore

Crop production is a major component of the multi-billion dollar agricultural and agrifood sector that employs over two million Canadians. This production is threatened by an increase in fungal diseases that are spread by massive numbers of resistant spores. The current research focus on disease formation has not produced new ways to fight fungal diseases. Here I present an alternative focus, blocking spore production and disease spread, as an area where novel approaches for battling fungi could be developed. We have known about the role of spores since the discovery that microbes cause disease. Obvious signs of fungal disease in crops are often associated with spore production. However our knowledge of how fungi influence plants to help them develop and disperse spores is limited. My laboratory has developed techniques for investigating fungal plant disease using the common corn smut fungus, Ustilago maydis. We are determining: 1. How the fungus uses hormones to time spore formation; 2. How different fungi manipulate the host to produce spores, and 3. How dormant spores become active We discovered that U. maydis produces cytokinins (CKs), plant hormones that alter the plant as disease develops. U. maydis can also detect CKs during infection suggesting that it might monitor levels of CKs in order to time the production of its spores. We will investigate which genes the fungus and the plant turn on and off when CKs are present. Then we will determine how altering the expression of these genes influences spore development. We found that U. maydis can cross with a closely related fungus Sporisorium reilianum to produce hybrids. Both parents infect maize but U. maydis produces disease symptoms and spores around the site of infection, whereas, S. reilianum enters maize and grows systemically producing disease symptoms and spores only in the tassels and cobs. The hybrids grow similar to U. maydis in culture but in the plant they do not produce spores. We will determine which of the U. maydis pathogenesis genes are turned on or off in the hybrid during infection and whether changing the expression of certain genes can help the hybrid form spores. This will identify genes with roles in spore production and uncover how hybridization could lead to new types of pathogens. In the third project we will investigate another aspect of disease spread, the germination of spores. When formed, these resistant structures become dormant. We have developed tools to help us study how U. maydis controls the return to metabolic activity as spores germinate. Understanding this return to a disease producing state is controlled may allow us to uncover novel ways of stopping it and of preventing disease spread. The knowledge gained through this research will contribute to the development of novel approaches for preventing fungal disease spread to improve the sustainability of crop production

农作物生产是价值数十亿美元的农业和农业食品部门的主要组成部分，该部门雇用了200多万加拿大人。这种生产受到真菌疾病增加的威胁，这些疾病是由大量耐药孢子传播的。目前的研究主要集中在疾病的形成上，但并没有找到对抗真菌疾病的新方法。在这里，我提出了另一个重点，阻止孢子的产生和疾病的传播，作为一个领域，可以开发新的方法来对抗真菌。