Physiological adjustments of wheat to drought stress as influenced by osmoprotectants and cytokinins

Glycine betaine (GB), Trehalose (Tre) and proline function as compatible solutes and are up regulated in plants under drought stress. In physiological responses, these play an osmoprotective role enabling the plants to better tolerate the adverse conditions of growth. In the present study, the effect of exogenous application of GB and Tre along with cytokinins (Kn, BA) applied during vegetative and anthesis stages to wheat cultivars (HD2967, PBW660 and WH1105) has been investigated. Proline content significantly increased under drought stress in all the three cultivars. Application of Tre along with both Kn and BA reduced the accumulation of proline in leaves at vegetative and anthesis stage. Drought stress conditions favoured accumulation of GB and choline in leaves of wheat cultivars and percent increase was more in PBW660. GB and Tre further improved accumulation of endogenous glycine betaine and choline. This advantageous effect of the osmoprotectants in combination with cytokinins alleviated growth inhibition during drought and improved the number of productive tillers and grains.