System responses to long-term drought and re-watering of two contrasting alfalfa varieties

Plant J. 2011 Dec;68(5):871-89. doi: 10.1111/j.1365-313X.2011.04738.x. Epub 2011 Oct 4.


Systems analysis of two alfalfa varieties, Wisfal (Medicago sativa ssp. falcata var. Wisfal) and Chilean (M. sativa ssp. sativa var. Chilean), with contrasting tolerance/sensitivity to drought revealed common and divergent responses to drought stress. At a qualitative level, molecular, biochemical, and physiological responses to drought stress were similar in the two varieties, indicating that they employ the same strategies to cope with drought. However, quantitative differences in responses at all levels were revealed that may contribute to greater drought tolerance in Wisfal. These included lower stomatal density and conductance in Wisfal; delayed leaf senescence compared with Chilean; greater root growth following a drought episode, and greater accumulation of osmolytes, including raffinose and galactinol, and flavonoid antioxidants in roots and/or shoots of Wisfal. Genes encoding transcription factors and other regulatory proteins, and genes involved in the biosynthesis of osmolytes and (iso)flavonoids were differentially regulated between the two varieties and represent potential targets for improving drought tolerance in alfalfa in the future.

Publication types

  • Comparative Study
  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, Non-P.H.S.

MeSH terms

  • Acclimatization
  • Antioxidants / metabolism
  • Disaccharides / metabolism
  • Droughts*
  • Flavonoids / biosynthesis
  • Gene Expression Regulation, Plant
  • Genes, Plant
  • Genes, Regulator
  • Medicago sativa / genetics
  • Medicago sativa / metabolism
  • Medicago sativa / physiology*
  • Photosynthesis
  • Plant Leaves / metabolism
  • Plant Leaves / physiology
  • Plant Roots / metabolism*
  • Plant Roots / physiology
  • Plant Stomata / physiology
  • Raffinose / metabolism
  • Species Specificity
  • Stress, Physiological
  • Time Factors
  • Transcription Factors / genetics
  • Transcription Factors / metabolism
  • Transcription, Genetic
  • Water / metabolism*


  • Antioxidants
  • Disaccharides
  • Flavonoids
  • Transcription Factors
  • Water
  • 6 beta-galactinol
  • Raffinose