Exogenous application of strigolactone alleviates drought stress in maize seedlings by regulating the physiological and antioxidants defense mechanisms

Drought stress is an alarming threat to food security in the climate change scenario. This study was conducted to evaluate the potential of strigolactone for drought tolerance in maize seedlings. The treatments consisted of two water regimes, i.e., (1) well-watered, at 80% water holding capacity (WHC) and (2) drought stress, at 40% WHC which were factorally combined with three Strigolactone concentrations (0, 10 and 20 µM) as foliar spray. Results revealed that drought stress diminishes the seedling growth, plant water relations and photosynthetic activities by producing more reactive oxygen species which lead to higher oxidative damage in maize seedlings. Application of strigolactone improved plant growth attributes by improving the gas exchange parameters, water relations and chlorophyll pigments. Application of strigolactone also enhanced the enzymatic antioxidants activities, including superoxide dismutase, peroxidase, catalase and ascorbate peroxidase in stressed seedlings over control. In conclusion, strigolactone improved the water relations, increased photosynthetic pigments and gas exchange parameters and enhanced antioxidant enzymatic activities to impart drought stress tolerance in maize seedlings. To best of our knowledge, this is the first study on role on strigolactone on drought stress tolerance mechanism in maize seedling.