Meeting Abstract
Drought is a major source of abiotic stress for plants, and poses an increasing threat to conservation, economic activities, and agriculture as climate change increases the stochasticity of precipitation events worldwide. Drought tolerance varies widely in the plant kingdom, both between species and across differently adapted populations within species. Water stress leads to decreased photosynthetic capacity, and can diminish vegetative growth and reproductive allocation, both of which have serious consequences for agricultural and bio-energy crops. Previous work has shown that the effects of drought stress also vary across different life stages. My research examines the physiological and transcriptomic responses to water limitation across life stages in the wild foxtail millet, Setaria viridis, a close relative of the agriculturally important foxtail millet, Setaria italica. In a drought stress experiment using 9 S. viridis populations from diverse geographical locations, population significantly influenced the number of days that plants took to reach a photosynthetic rate of zero. Flowering was found to be negatively correlated with drought tolerance. Further experiments will compare photosynthetic capacity, chlorophyll fluorescence levels, flowering time, seed production, and gene expression patterns in differently adapted populations of S. viridis exposed to drought stress at three different life stages (pre-reproductive, bud-stage, and flowering). This research will help elucidate the effects of population adaptation and life stage on drought stress response in a close relative of an important agricultural crop.
