Do Symbioses Determine Plant Species Abundances? How Endophytic Fungi May Control Rarity, Dominance, and Invasiveness of Grasses

共生决定植物物种丰度吗？

• 批准号: 0542781
• 负责人: Jennifer Rudgers
• 金额: $ 44.99万
• 依托单位: William Marsh Rice University
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2006
• 资助国家: 美国
• 起止时间: 2006-04-15 至 2012-03-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0542781&HistoricalAwards=false
• 关键词: Do; Symbioses; Determine; Plant; Species

Species fundamentally vary in their abundance, spanning a range from federally endangered species to severely weedy invaders. Several hypotheses have been proposed to explain this pattern, but none sufficiently account for observed variation. In part, this failure might reflect the fact that microbial symbioses (widespread, mutually beneficial associations between microbes and plants) have been largely ignored. This proposal forges a new direction by evaluating the role of microbial symbioses in governing rarity and invasiveness. Taking advantage of the experimentally tractable symbioses between grasses and microbial endophytes (fungi that live within plant leaves), proposed experiments and demographic models test whether and how symbionts increase host abundance. In grasses, endophytes may improve host resistance to herbivory through the production of alkaloids toxic to insects and mammals and also may enhance host drought tolerance. Comparative experiments on paired rare and common grass species will test predictions that symbionts benefits are greater for common than rare host species and differ between native and non-native hosts, providing the most comprehensive study to date on the ecology of grass-endophyte symbioses. A clearer understanding of endophyte ecology can offer novel strategies for rare plant conservation and invasive plant control (e.g., via endophyte additions or eliminations). Through networks established in both Indiana and Texas, information will be broadly communicated to state agencies, preserve managers, seed companies, and conservation organizations. The work will additionally integrate teaching and research, by training graduate and undergraduate students as well as bringing contemporary research into the classroom.

物种的丰富程度从根本上不同，从联邦濒危物种到严重的杂草入侵者。 已经提出了几个假设来解释这种模式，但没有一个足以解释观察到的变化。 在某种程度上，这种失败可能反映了微生物共生（微生物和植物之间广泛的互利关系）在很大程度上被忽视了。这一提议通过评估微生物共生体在管理稀有性和入侵性中的作用，开辟了一个新的方向。 利用草类和微生物内生菌（生活在植物叶片内的真菌）之间易于实验处理的共生关系，提出的实验和人口模型测试共生体是否以及如何增加宿主丰度。 在禾本科植物中，内生菌可以通过产生对昆虫和哺乳动物有毒的生物碱来提高宿主对草食动物的抗性，还可以增强宿主的耐旱性。配对的稀有和常见的草种的比较实验将测试共生体的好处是更大的常见比稀有的宿主物种和本地和非本地主机之间的差异的预测，提供最全面的研究到目前为止的生态草内生菌共生。 更清楚地了解内生菌生态学可以为稀有植物保护和入侵植物控制提供新的策略（例如，通过内生菌添加或消除）。 通过在印第安纳州和得克萨斯州建立的网络，信息将广泛传达给州政府机构、保护区管理人员、种子公司和保护组织。这项工作还将通过培训研究生和本科生以及将当代研究带入课堂来整合教学和研究。