Seed priming with silicon and chitosan for alleviating water stress effects in maize (ZEA MAYS L.) by improving antioxidant enzyme activities, water status and photosynthesis. (15th July 2022) - Younas, Hafiza Samra
Abstract: Water stress is one of the most important yield limiting factors in maize ( Zea mays L.) around the world, particularly in developing countries which have limited access to reliable irrigation. Water stress can be overcome either by developing additional water resources or improving plant resistance. The use of different organic and inorganic substances might be important to improve plant resistance to water stress. Present study investigated the protective role of silicon (Si) and chitosan in maize under water stress. Experimental plan comprised of two soil moisture regimes i.e., 100% field capacity (FC) as control and 50% FC (water stress), two Si levels (0 and 0.5%), two chitosan levels (0 and 0.75%) with three replications. Silicon and chitosan were applied through seed priming. Water stress limited the plant growth and yield by inducing oxidative damage, chlorophyll and photosynthesis degradation, membrane destabilization and stomatal closure. Seed priming with Si and chitosan reversed the oxidative damage as evidenced by marked reduction in malondialdehyde (MDA) by activating catalase, peroxidase and superoxide dismutase. Application of Si and chitosan also improved soluble protein, chlorophyll, photosynthesis and potassium uptake, leading to enhanced plant growth and yield. Grain yield improved by 17.9, 9.86 and 26.3% at 100% FC while 54.2, 34.0 and 56.9% at 50% FC with Si, chitosan and Si + chitosan, respectively compared to respective soil moisture regime without Si and chitosan. It was suggested that integrated use of Si and chitosan via seed priming could be an important strategy for inducing resistance to water stress in maize.