Plant-fungal communication: using an endophytic insect pathogenic fungus as a model

植物-真菌通讯：以内生昆虫病原真菌为模型

• 批准号: RGPIN-2014-04496
• 负责人: Bidochka, Michael
• 金额: $ 2.48万
• 依托单位: Brock University
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2015
• 资助国家: 加拿大
• 起止时间: 2015-01-01 至 2016-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=587844
• 关键词: Plant; fungal; communication; using; endophytic

The commercially important insect pathogenic fungus, Metarhizium robertsii (= anisopliae) has a world-wide distribution and can be easily recovered from soils of different climates and ecological settings such as forested or agricultural habitats. My laboratory has shown that Metarhizium spp. are not only insect pathogens but also endophytes, with evidence that they can adhere to plant roots and colonize root cells. We have connected the lifestyles of Metarhizium as insect pathogens as well as endophytes and have shown that the relationship of this fungus is beneficial to the plant. We have shown that fungal mycelia from infected insects migrate to plant roots that are then colonized. Subsequently the insect-derived nitrogen is transferred to the plant. We hypothesize that this is a symbiotic association where insect nitrogen is provided to the plant by the fungus in exchange for plant carbon (i.e. carbohydrates). Elucidating the association of this fungus with plants could generate alternate ideas of nutrient cycling in plants, particularly nitrogen cycling. This fungal-insect-plant association could also contribute to the utility of fungi as insect pathogens particularly for insect pests that destroy plant roots. For example, in North America there are over 120 root feeding insects and in Canada insects that destroy plant roots include strawberry root weevil (Otiorhynchus ovatus), black vine weevil (O. sulcatus), several species of wireworms and cutworms (Euxoa spp.), Grape Root Borer (Vitacea polistiformis) and several forest root feeding insects. My next progression in the research program, which is described in this proposal, is to understand at a greater depth, the association of this insect pathogenic fungus with the plant. The overall objective of this proposal is to increase our understanding of the association of endophytic insect pathogenic fungi with host plants and the mechanisms that allow these associations. We will endeavor to test the following hypotheses: Hypothesis 1: That the plant reciprocates fungal nitrogen transfer with carbon transfer. Hypothesis 2: That soil nitrogen levels affect endophytic association by M. robertsii. Hypothesis 3: That there is plant-fungus communication that accomodates endophytic colonization. Hypothesis 4: That M. anisopliae protects plants from a large array of plant pathogenic fungi, root as well as systemic pathogens.

罗伯特绿僵菌（绿僵菌）是一种具有重要商业价值的昆虫病原真菌，它在世界范围内分布，可以很容易地从不同气候和生态环境的土壤中恢复，如森林或农业栖息地。我的实验室已经证明，绿僵菌不仅是昆虫病原体，也是内生菌，有证据表明它们可以附着在植物的根上并定植在根细胞上。我们已经将绿僵菌的生活方式与昆虫病原体和内生菌联系起来，并表明这种真菌的关系对植物有益。我们已经证明，受感染昆虫的真菌菌丝体迁移到植物根部，然后定植。随后，昆虫产生的氮被转移到植物中。我们假设这是一种共生关系，真菌向植物提供昆虫氮，以换取植物碳（即碳水化合物）。阐明这种真菌与植物的关系，可以为植物养分循环，特别是氮循环提供新的思路。这种真菌-昆虫-植物的联系也有助于真菌作为昆虫病原体的效用，特别是对破坏植物根系的害虫。例如，在北美有超过120种食根昆虫，在加拿大，破坏植物根系的昆虫包括草莓根象鼻虫（Otiorhynchus ovatus）、黑藤象鼻虫（O. sulcatus）、几种线虫和切虫（Euxoa spp.）、葡萄根螟虫（Vitacea polistiformis）和几种森林食根昆虫。