Biochemical responses to drought stress in mulberry (Morus alba L.): evaluation of proline, glycine betaine and abscisic acid accumulation in five cultivars

Abstract

Five popularly grown mulberry cultivars (K-2, MR-2, TR-10, BC2-59 and S-13) were subjected to drought stress by withholding irrigation, to obtain leaf water potentials (W w ) ranging from -0.75, -1.50 and -2.25 MPa. Accumulation of proline, glycine betaine and abscisic acid (ABA) were quantified in control and water stressed mulberry leaves. The activities of enzymes involved in proline accumulation including glutamate dehydrogenase (EC1.4.1.2-4), pyrroline-5-carboxylate synthetase (EC 1.2.1.41), pyrroline-5-carboxylate reductase (EC1.5.1.2), ornithine transaminase (EC 2.6.1.13) were significantly enhanced in the leaves of all the cultivars with decreasing leaf water potentials, while the activities of proline dehydrogenase (EC 1.5.1.2) were reduced with progressive increase in water stress. Accumulation of proline, glycine betaine and abscisic acid was relatively higher in S-13 and BC2-59 compared to K-2, MR-2 and TR-10 under water deficit conditions. Our results demonstrate that S-13 and BC2-59 have superior osmoprotectant mechanisms under water-limited growth regimes.

Influence of exogenously applied paclobutrazol on some physiological traits and growth of Stevia rebaudiana under in vitro drought stress

“…P5CS and PDH activity was not affected by drought stress and PBZ treatment. Chaitanya et al (2009) reported that PDH and P5CS activity increased in the mulberry under drought stress which was followed by increase in proline accumulation. On the contrary, in this study no correlation was observed between enzyme activity and proline accumulation.…”

Regulated deficit irrigation for crop production under drought stress. A review

“…The activities of antioxidant enzymes under water stress vary among plant species or cultivars (Chaitanya et al 2009). The sensitivity of the enzymatic response depends on intrinsic genetic traits in plants.…”

Physio-Biochemical Responses of Oil Palm (Elaeis guineensisJacq.) Seedlings to Mannitol- and Polyethylene Glycol-Induced Iso-Osmotic Stresses

“…Proline accumulation in stress conditions was not only dependent on the type of stressor but also the plant species. In addition, the ornithine-δ-aminotransferase (δ-OAT), glutamate dehydrogenase (GDH), and proline-5-carboxylase reductase (P5CR) in the proline biosynthesis pathway in drought-stressed mulberry (Chaitanya et al, 2009) and Sesuvium portulacastrum (Slama et al, 2006) have been investigated. In this study, REL in oil palm seedlings was increased under PEG-and mannitol-induced osmotic stress, as was proline accumulation.…”