The Role of Endophytes in Semi-Arid, Forest-Grassland Communities

内生菌在半干旱森林草原群落中的作用

• 批准号: 9727020
• 负责人: Stanley Faeth
• 金额: $ 35万
• 依托单位: Arizona State University
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 1998
• 资助国家: 美国
• 起止时间: 1998-03-15 至 2002-02-28
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=9727020&HistoricalAwards=false
• 关键词: Role; Endophytes; Semi; Arid; Forest

Faeth 97 27020 Endophytic fungi frequently live intracellularly within the tissues of plants with little obvious indication of their presence. In grasses these symbionts have been thought to increase plant resistance to herbivory, resistance to drought, and the competitive abilities of some plants in their interactions with their neighbors. Despite the widespread occurrence of these associations, however, information on the nature of fungal-plant interactions remains limited. This project will continue investigations of the relationship between endophytic fungus, Neotyphodium, and Arizona fescue an economically important range grass in the southwest. An earlier series of experiments, funded by the Ecology program at NSF, failed to demonstrate that these fungi, provide any resistance to grazing by invertebrate herbivores, in contrast with widely held conventional wisdom that such a resistance is provided. Alternative hypotheses to be tested in this new work center on the observation that plants increase root biomass and, possibly, osmoregulatory efficiency when infected by fungi. It will examine the varying survival of seed, seedling, and mature-plant stages of fescue under different conditions of soil moisture and nitrogen along with fire frequency and intensity for different plant genotypes. It will employ a series of field and laboratory experiments to test the notion that the Neotyphodium-Arizona fescue mutualism is context dependent. It will also consider that fire may be an evolutionary factor that maintains these associations. The results of this work will increase the understanding of the role of microoganisms in plant-animal interactions, plant population dynamics and the organization of plant-microbe-herbivore communities. It will shed insight into the evolution, ecology and maintenance of mutualistic interactions. It will also provide useful information for the maintenance important southwestern grasslands.

内生真菌通常生活在植物组织的细胞内，很少有明显的迹象表明它们的存在。在禾草中，这些共生体被认为可以增强植物的抗草食性、抗旱性，以及一些植物在与邻近植物相互作用中的竞争能力。尽管这些关联广泛存在，然而，关于真菌-植物相互作用性质的信息仍然有限。该项目将继续研究内生真菌、新伤寒菌和亚利桑那州羊茅之间的关系，这是西南地区一种重要的经济范围草。由美国国家科学基金会（NSF）生态学项目资助的一系列早期实验，未能证明这些真菌对无脊椎食草动物的放牧有任何抵抗力，这与广泛持有的传统观点相反。在这项新工作中有待检验的其他假设集中在观察植物在受到真菌感染时增加根系生物量，并可能增加渗透调节效率。研究不同基因型羊茅在不同土壤水分、氮素、火灾频率和强度条件下的种子、幼苗和成熟期存活率的变化。它将采用一系列的实地和实验室实验来检验Neotyphodium-Arizona羊茅共生关系依赖于环境的概念。它还将考虑火可能是维持这些联系的进化因素。这项工作的结果将增加对微生物在植物-动物相互作用，植物种群动态和植物-微生物-食草动物群落组织中的作用的理解。它将有助于深入了解相互作用的进化、生态和维持。这也将为西南重要草原的维护提供有用的信息。