Preferential Allocation of Photosynthate toward Better Mutualists, Spatial Structure, and the Maintenance of the Arbuscular Mycorrhizal Mutualism

光合产物向更好的互利共生、空间结构和丛枝菌根互利共生的维持的优先分配

• 批准号: 0919434
• 负责人: James Bever
• 金额: $ 46.85万
• 依托单位: Indiana University
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2009
• 资助国家: 美国
• 起止时间: 2009-08-01 至 2013-07-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0919434&HistoricalAwards=false
• 关键词: Preferential; Allocation; Photosynthate; toward; Better

Arbuscular mycorrhizal (AM) fungi form beneficial associations with the roots of most plant species, including most crop plants. These fungi increase plant access to immobile soil minerals and receive plant carbohydrates in return. While this interaction can be mutually beneficial between plants and fungi, the extent to which the fungi increase plant growth varies across soil environments and fungal isolates. Moreover the benefit has been observed to increase and degrade over time. Currently, there is little basis for predictive understanding of these dynamics. Recent work has demonstrated that plants can allocate their carbohydrates preferentially toward the most beneficial fungus. This preferential allocation allows the effective fungus to increase in the face of competition from non-beneficial fungi provided that there is sufficient spatial separation between the fungi within a plant's root system. Preferential allocation may form a foundation on which to understand the persistence of beneficial fungi and change in their abundance over time. The proposed work will test resource triggers and environmental dependence of preferential allocation and test patterns of preferential allocation across plant and fungal species. Finally, fungal population response to manipulation of spatial mixing of the fungi within the plant root system will be evaluated. These results will be used to develop predictions for changes in abundance of beneficial fungi across environmental gradients. The proposed research will train undergraduates, graduate students and postdoctoral scientists in techniques used to measure and manipulate beneficial AM fungi. In addition, this research will create opportunities for independent undergraduate research. In particular, an experiment testing how mycorrhizal fungi may benefit restoration of a native prairie on the campus of Indiana University will be initiated as part of a non-majors course in environmental biology. Students will thus be exposed to multiple aspects of ecological research related to this project.

丛枝菌根 (AM) 真菌与大多数植物物种（包括大多数农作物）的根部形成有益的联系。 这些真菌增加了植物获取固定土壤矿物质的机会，并获得植物碳水化合物作为回报。 虽然植物和真菌之间的这种相互作用可能是互利的，但真菌促进植物生长的程度因土壤环境和真菌分离株而异。 此外，据观察，这种益处会随着时间的推移而增加或减少。 目前，对这些动态的预测性理解还没有什么基础。 最近的研究表明，植物可以优先将碳水化合物分配给最有益的真菌。 如果植物根系内的真菌之间有足够的空间分离，这种优先分配允许有效真菌在面对非有益真菌的竞争时增加。 优先分配可以为了解有益真菌的持久性及其丰度随时间的变化奠定基础。 拟议的工作将测试优先分配的资源触发因素和环境依赖性，并测试跨植物和真菌物种的优先分配模式。 最后，将评估真菌种群对植物根系内真菌空间混合操纵的反应。 这些结果将用于预测环境梯度中有益真菌丰度的变化。 拟议的研究将为本科生、研究生和博士后科学家提供测量和操纵有益 AM 真菌的技术培训。 此外，这项研究将为独立本科生研究创造机会。 特别是，作为环境生物学非专业课程的一部分，将启动一项实验，测试菌根真菌如何有利于印第安纳大学校园内原生草原的恢复。因此，学生将接触到与该项目相关的生态研究的多个方面。