DISSERTATION RESEARCH: Molecular and metabolic dissection of the symbiosis between a native prairie grass and its fungal root endophyte

植物拥有一系列生活在细胞内的微生物。有益的菌根真菌可能是这种微生物最著名的例子：超过80%的陆地植物在它们的根部寄生这些真菌。菌根真菌可以提高植物的生长、养分吸收、水分利用效率和对病原菌的抗性。因此，它们在作物管理方面有很大的潜力。最近的研究表明，除了菌根真菌外，另一类真菌--内生菌--可能也同样丰富。初步结果表明，这些内生菌的范围从有害的植物病原体到显着改善植物生长和表现的互助体。虽然植物生长的改善是重要和有趣的，但更重要的可能是理解为什么一些内生真菌如此显著地促进植物生长，而另一些则不是。本研究利用现代分子工具，如大规模基因芯片和代谢物分析，来提高我们对本地高草草原草(Andrepogon Gerardii)为什么对这些内生真菌的定植做出积极反应的理解。与提高水分利用效率、更大的光合作用活性和改善养分吸收/转移有关的假设将得到检验。这一研究计划的结果将扩大我们对宿主-微生物相互作用背后的机制的理解，并将有助于寻找生物作物管理工具。除了研究生培训，还将纳入课堂练习，通过经验测试单个内生菌之间的变异性或植物反应的潜在机制，以提供新颖的本科生学习体验。

Plants host a range of microbes that live inside their cells. The beneficial mycorrhizal fungi may be the best known example of such microbes: over 80% of all land plants host these fungi in their roots. The mycorrhizal fungi often improve plant growth, nutrient uptake, water use efficiency, and resistance against pathogens. Therefore they have a great potential in crop management. Recent research suggests that, in addition to the mycorrhizal fungi, another group of fungi, the endophytes, may be equally abundant. Preliminary results indicate that these endophytes range from detrimental plant pathogens to mutualists that significantly improve plant growth and performance. While the improved plant growth is important and interesting, it may be even more important to understand why some endophytic fungi so greatly improve the plant growth while others do not. This reasearch employs modern molecular tools such as large-scale microarray and metabolite analyses to improve our understanding of why a native tallgrass prairie grass (Andropogon gerardii) responds positively to colonization by these endophytic fungi. Hypotheses related to improved water use efficiency, greater photosynthetic activity and improved nutrient uptake/transfer will be tested. The results of this research program will expand our understanding of the mechanisms behind the host-microbe interactions and will assist in the search for biological crop management tools. In addition to graduate student training, classroom exercises that empirically test the variability among individual endophytes or the underlying mechanisms of the plant responses will be incorporated to provide novel undergraduate learning experiences.