ECA-PGR: Identifying Host Factors that Influence the Association of Tall Fescue (Festuca arundinacea) with beneficial Epichloe endophytes

University Of Georgia Research Foundation Inc, Athens GA

Investigators

Abstract

Meeting the demand for increased crop and agriculture production in the 21st century will require innovative and transformative approaches. One area with great potential for benefitting agriculture is harnessing beneficial microbes for agriculture. Although some microbes cause disease, many others are harmless and some even benefit the plant. This project studies one such beneficial partnership to determine how the plant and microbe work together to improve plant health. Tall fescue, an important grass for livestock, can withstand much greater stress (heat, drought, etc.) when a specific fungus grows inside it, although some types of the fungus also produce a toxin that can sicken livestock. Thousands of tall fescue plants will be analyzed to find the plant genes that influence the production of these toxins to understand how plants can influence their microbe partners. Studying what changes occur in newly infected tall fescue seedlings will lead to a better understanding of how this partnership is established. Comparing plants with and without the fungus under heat stress will help determine how both plant and fungus work together to withstand the stress. The project will assist middle- and high-school teachers in developing hands-on teaching projects related to these topics that they can implement in their own classrooms. Together, these studies will increase understanding of how plant-microbe partnerships work and how to use them to improve agricultural production and sustainability. Even though highly beneficial plant-microbe interactions are known, most of them are too poorly understood to exploit fully, and the mechanisms behind them are largely unknown. This project will address these knowledge gaps by identifying genes and pathways that influence the beneficial symbiosis between tall fescue (Festuca arundinacea), an economically important forage grass, and its obligate fungal endophytes. Specifically, this project will (1) create a large, multiparental mapping population of tall fescue and identify the plant genes that control the production of economically relevant fungal defense compounds, (2) profile the transcriptomic response of newly infected tall fescue seedlings to identify the pathways involved in establishing a successful host-endophyte partnership, and (3) identify the plant transcriptomic response to heat stress with and without endophytes to identify the genes and transcriptional modules responsible for the plant achieving enhanced stress resistance in the presence of the endophyte. These results will identify the key genes involved in an important plant-fungus symbiosis and will serve as a model for beneficial plant-microbe interactions more generally. These results will have direct application to the US forage industry, and will more broadly inform investigations into agricultural plant-microbe interactions in general. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.