Find in Library

Alfalfa (<i>Medicago sativa</i> L.) is an extensively grown perennial forage legume, and although it is relatively drought tolerant, it consumes high amounts of water and depends upon irrigation in many regions. Given the progressive decline in water available for irrigation, as well as an escalation in climate change-related droughts, there is a critical need to develop alfalfa cultivars with improved drought resilience. <i>M. sativa</i> subsp. <i>falcata</i> is a close relative of the predominantly cultivated <i>M. sativa</i> subsp. <i>sativa</i>, and certain accessions have been demonstrated to exhibit superior performance under drought. As such, we endeavoured to carry out comparative physiological, biochemical, and transcriptomic evaluations of an as of yet unstudied drought-tolerant <i>M. sativa</i> subsp. <i>falcata</i> accession (PI 641381) and a relatively drought-susceptible <i>M. sativa</i> subsp. <i>sativa</i> cultivar (Beaver) to increase our understanding of the molecular mechanisms behind the enhanced ability of <i>falcata</i> to withstand water deficiency. Our findings indicate that unlike the small number of <i>falcata</i> genotypes assessed previously, <i>falcata</i> PI 641381 may exploit smaller, thicker leaves, as well as an increase in the baseline transcriptional levels of genes encoding particular transcription factors, protective proteins, and enzymes involved in the biosynthesis of stress-related compounds. These findings imply that different <i>falcata</i> accessions/genotypes may employ distinct drought response mechanisms, and the study provides a suite of candidate genes to facilitate the breeding of alfalfa with enhanced drought resilience in the future.