Melatonin-mediated drought resistance in Avena sativa under climatic stress conditions

Water scarcity induced by drought stress adversely affects growth and development processes in plants. Melatonin, a stress-alleviating biostimulator with strong antioxidant properties, plays a vital role in enhancing plant resilience under such conditions. To further investigate, this study was conducted to examine the effects of exogenous melatonin application on Avena sativa under drought stress. A pot culture experiment was conducted in2021-22 and 2022-23 during the rabi season in the Institute of Environmental Studies, Kurukshetra University, Kurukshetra, Haryana, India, to assess the impacts of drought stress and melatonin on A. sativa. Plants were grown under varying drought stress levels (100%, 75%, 50%, 25% WHC) with and without foliar-applied melatonin (100 µM). Drought stress significantly reduced shoot length, root length, biomass, and chlorophyll a and b content, while total protein content and proline content were enhanced. Melatonin alleviated the impacts of drought stress and positively affected morpho-physiological parameters. Melatonin further enhanced protein and proline content in A. sativa plants. This study has proved the hypothesis that exogenous foliar application of melatonin can be used as an effective strategy to alleviate the impacts of drought stress.