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.
