Abstract
A major challenge is the growing demand for energy and the environmental consequences of increasing energy production and use. In particular, burning of fossil fuels and subsequent increases in atmospheric CO2 is thought to be a major driver of climate change. In recent history, CO2 has increased from a concentration of ~280 ppm to more than 400 ppm today. Although predictions vary, most climate scientists believe these changes will result in severe alterations to weather patterns, especially temperature and precipitation, with potentially dramatic impacts. Alternative energies are therefore a priority with the hope that advances can reduce the use of fossil fuels. The DOE has set a goal of displacing 30% of domestic gasoline demand with biofuels by 2030. This goal will require increasing our understanding of factors influencing both plant productivity and ecosystem sustainability.
Less carbon-intensive energy sources are needed to reduce greenhouse gas emissions and mitigate climate change. There is growing interest in the potential of biofuels for meeting this need. A critical question is whether large-scale biofuel production can be sustainable over the time scales needed to diminish our carbon debt from fossil fuel consumption. The carbon balance and ultimately the sustainability of biofuel feedstock production is the result of complex climate-coupled interactions between carbon fixation, sequestration, and release through combustion. Similarly, the long-term productivity of biofuels depends on the environmental factors impacting plant health and growth, often related to soil resources which involve complex interactions at the plant-microbe-soil interface.
Panicum represents a large genus of many North American prairie grass species. These include switchgrass (Panicum virgatum), a biofuel crop candidate with wide geographic range, as well as Panicum hallii, a close relative to switchgrass, which serves as a model system for the study of Panicum genetics due to its diploid genome and short growth cycles. We here explore Panicum microbiomes in shoots and roots (Figure 1) across a latitudinal gradient spanning 24 degrees of latitude (Figure 2) linking bacterial and fungal community composition and diversity to plant genetic and environmental characteristics. These insights will enhance our understanding of plant-microbe interactions to arrive at more sustainable management practices for biofuel crops in a changing global climate.
