Control of root colonization of mutualistic and pathogenic fungi via plant phosphate starvation responses

2019 Fiscal Year Final Research Report

• Project/Area Number: 18K14466
• Research Category: Grant-in-Aid for Early-Career Scientists
• Allocation Type: Multi-year Fund
• Review Section: Basic Section 39040:Plant protection science-related
• Research Institution: Nara Institute of Science and Technology
• Principal Investigator: Hiruma Kei 奈良先端科学技術大学院大学, 先端科学技術研究科, 助教 (20714504)
• Project Period (FY): 2018-04-01 – 2020-03-31
• Keywords: 共生菌 / 病原菌 / リン枯渇適応反応 / トリプトファン代謝 / 細胞タイプ / Colletotrichum

Outline of Final Research Achievements

Depending on nutrient availability, plants promote or repress beneficial interactions with microbes. However, little is known about mechanisms by which host plants regulate microbes in a manner dependent of nutrient availability. This study shows that MYB-type transcription factors PHR1 and its parlor PHL1, two major regulators of phosphate starvation responses (PSR), positively regulate the expression of A. thaliana genes related to biosynthesis of tryptophan-derived secondary metabolites during interactions with the root beneficial fungus Colletotrichum tofieldiae (Ct). Furthermore, this study identifies that one of the branch of tryptophan-derived secondary pathway regulated by PHR1/PHL1 is required for repression of Ct growth as well as Ct-mediated plant growth promotion under low phosphate conditions. Thus, this study points to a functional link between phosphate starvation responses and anti-fungal secondary metabolites during interactions with beneficial fungi.

Free Research Field

植物微生物相互作用

Academic Significance and Societal Importance of the Research Achievements

植物は自身の栄養状況に応じて巧みに共生微生物の感染を制御していることが考えられ、その仕組みを知ることは共生微生物の有益な機能を活用していく上でも重要である。今回、植物がリン酸枯渇を制御する転写因子を介して共生微生物の感染を制御していることが判明したことに加えて、実際にPHR1/PHL1が制御する微生物感染を抑止する実態も発見した。これらの知見は、共生微生物を暴走させることなく制御し安全に適応していくために有益だと考えられる。