Shifting Costs and Benefits of Systemic Endophyte Interactions With Native Grass Hosts

内生菌是指生活在植物内部但不引起疾病的真菌。相反，内生菌被认为通过提高植物对干旱、食草动物、种子捕食者、病原体和根食性的抵抗力，提高发芽率、营养吸收和竞争能力而有益于植物。所有植物中都有内生菌，包括农用作物和草坪草。它们用于草坪草中以提高草的性能，但也可能因其毒性作用而对牲畜造成伤害。然而，人们对原生禾本科植物内生菌的作用知之甚少。内生菌的好处往往与农艺草不同。我们的研究旨在确定两种广泛分布的西南原生禾本科植物——亚利桑那羊茅和睡草——中无性、种子传播的内生菌的成本和收益。我们的目标是通过实验测试新伤寒感染的成本和收益取决于植物和内生菌基因型和环境。我们将实施两个主要的田间试验，控制植物基因型和内生菌感染，土壤湿度水平和无脊椎动物和脊椎动物的食草性。我们的研究结果将为内生植物与其寄主草之间的基本相互作用提供见解，并可能具有与饲料草相关的重要应用方面。

Project SummaryEndophytes are fungi that live internally in plants but do not cause disease. Instead, endophytes are thought to benefit the plant by increasing resistance to drought, herbivores, and seed predators, pathogens and root feeders and increasing germination rates, nutrient uptake, and competitive abilities. Endophytes are found in all plants, including agronomic crops and turf grasses. They are used in turf grasses to increase performance of grasses, but may also cause harm livestock because of their toxic effects. However, little is known about the role of endophytes in native grasses. The benefits of endophytes are often not the same as in agronomic grasses. Our research seeks to determine the costs and benefits of asexual, seed borne endophytes in the genus Neotyphodium in two widespread SW native grasses, Arizona fescue and sleepy grass. Our goals are to experimentally test the cost and benefits of Neotyphodium infection depending on plant and endophyte genotype and environment. We will implement two major field experiments that control plant genotype and endophyte infection, soil moisture levels and herbivory by invertebrates and vertebrates. Our results will provide insights into basic interactions between endophytes and their host grasses, and may have important applied aspects related to forage grasses.