Comparative physiological and leaf proteomic analyses revealed the tolerant and sensitive traits to drought stress in two wheat parental lines and their F6 progenies

Comparative physiological and proteomic analyses of two wheat cultivars Arg (resistant to drought), Arta (sensitive to drought) and four F6 lines (B1, B2, W1, W2) derived from their crossbreed lead us to discriminate the Arg, B1 and B2 lines to be resistant toward strong leaf water deficit. Proteins belonging to carbon metabolism, photosynthesis and detoxification/defense showed the major change. Tolerant Arg showed the accumulation of stress-responsive proteins under drought stress higher than in sensitive Arta. The high level of Cu/Zn superoxide dismutase, and two chloroplastic encoded enzymes indicate that their accumulation might improve stress resistance. Morphological and physiological traits of B1 and B2 confirmed that these lines are tolerant to drought stress. Proline and MDA contents are higher and lower, respectively, in these two lines than in other ones. This act synergistically with the modulation of primary metabolisms and protection against dehydration and oxidative damage resulting in the improvements of survival of the seedlings, greater vegetative vigor and productive capacity that also exceeds that of the tolerant Arg parental line. For all these evidences, the B1 and B2 progenies could be selected as the best lines in the future cultivation trials for wheat breeding under moderate and severe drought conditions.