Hydrogen peroxide regulates antioxidant responses and redox related proteins in drought stressed wheat seedlings.

Hydrogen peroxide plays pivotal role as a potent regulator in signalling pathways when the plant is under stress. The current study appraised the potential of hydrogen peroxide through seed pre-treatment on the seedling growth and defense responses of three wheat cultivars i.e. PBW 644 (tolerant), PBW 621 and HD 2967 (sensitive) grown under drought stress. Imposition of drought stress reduced seedling growth of all the three wheat cultivars. Pre-treatment of seeds with 60 mM H2O2 alleviated water stress induced growth inhibition in all the three wheat cultivars. Further, it enhanced the drought tolerance of PBW 644 by upregulating SOD, POX, APX and GR enzymes accompanied by an increase in total phenols and ascorbate content. H2O2 treatment also protected the sensitive cultivars from drought stress by increasing CAT, POX, APX, MDHAR and GR enzymes. The contents of osmolytes were comparable or slightly higher as compared to stressed seedlings. The levels of MDA content were reduced in the treated seedlings of all the cultivars which further revealed the role of H2O2 pre-treatment in alleviating membrane damage. The comprehensive scrutiny of proteins differentially expressed in control, stressed and H2O2 primed stressed seedlings revealed that drought stress enhanced the expression of proteins involved in photosynthesis, protein biosynthesis and degradation, carbohydrate metabolism, fatty acid metabolism, nucleic acid metabolism, phytohormone response, defense and regulation, whereas H2O2 pre-treatment led to over expression of proteins which had functions in processes such as defense, redox homeostasis and photosynthesis. SUPPLEMENTARY INFORMATION: The online version of this article (10.1007/s12298-021-00937-z). © Prof. H.S. Srivastava Foundation for Science and Society 2021.