Exogenous Trehalose Improves Cotton Growth by Modulating Antioxidant Defense Under Salinity-Induced Osmotic Stress

Abstract

Use of osmoprotectants is a possible strategy for plants to survive under adverse environmental conditions. The current study emphasizes the ameliorative role of trehalose, in mitigating the detrimental effects of salt stress, in cotton plants. Three concentrations of trehalose (0, 5 and 50 mM) were applied to plant foliage, subjected to varying levels (0, 11 and 17 dSm-1) of salinity. Salt stress disturbed the sodium and potassium concentrations in leaves and roots of plants. Different morphological traits of plants including number of leaves, leaf fresh weight, shoot fresh weight, root fresh weight, plant height, leaf dry weight and root dry weight were severely hampered by salt stress. The absence of necrosis in cotton leaves under salt treatments indicated that growth was primarily restricted by the osmotic component of salt stress. Activities of antioxidant enzymes (superoxide dismutase, peroxidase and catalase) in plant leaves were increased in response to salt stress. Treatment of stressed plants with trehalose considerably improved the growth attributes and reduced the activities of antioxidant enzymes, indicating its ameliorative role in salt stress alleviation. However, no improvement was noted in K+ and Na+ dynamics by trehalose application. In conclusion, trehalose plays a key role in survival of plants under elevated saline conditions.