Project description:Two alfalfa varieties, 'Chilean' (M. sativa ssp. sativa var. Chilean, drought sensitive) and 'Wisfal' (M. sativa ssp. falcata var. Wisfal, drought tolerant), with contrasting water use efficiency were subjected to water withholding for 11 days followed by re-watering. Samples were taken for well-watered plants and plants after five, eight, eleven days of drought stress as well as plants after recovery for one day following drought stress. Roots and shoots were sampled and analyzed separately by expression profiling using Affymetrix Medicago GeneChip.