Effect of drought acclimation on oxidative stress and transcript expression in wheat (Triticum aestivum L.)

Abstract

The effects of drought acclimation on plant growth and water relations, membrane status, photosynthetic activity, proline content, membrane lipid peroxidation, enzyme antioxidant activity, and drought-responsive gene expression patterns were investigated under progressive drought conditions with drought acclimation (DA) and non-acclimation (NA) treatments in four wheat genotypes. Initial water stressapplied at 10 days after seedling transfer induced acclimation to subsequent water stress (S2), following re-watering. A reversible decline in plant growth and water relations, membrane stability, and photosynthetic activity resulted in increased lipid peroxidation, reactive oxygen species, membrane injury, enzyme antioxidant activities, and H2O2 and osmolyte accumulation in DA plants. TaWRKY2, TaNAC1, TaMYB2, TabHLH1, and TabZIP1 levels were upregulated to a greater extent in NA than in DA plants, during S2. The results suggest wheat plants employ physiological, biochemical and molecular mechanism under drought improving their ability to survive subsequent water stress in the later period of growth and development.