Effect of Silicon under Water Deficit on Antioxidant Enzymes Activities at Different Phenological Stages in Wheat (Triticum aestivum L.)

A pot experiment was conducted to evaluate the effect of foliar application of silicon (Si) at different stages of growth in wheat. Foliar treatment of silicon was given on 15^th and 30^th days after germination (DAG) and the plants were subjected to water deficit stress at booting, flowering and grain filling stages. The greater decline for relative water content (RWC) and hydrogen peroxide (H₂O₂) was observed in drought (Dr) as compared to Si + Dr treatment. Si + Dr treatment resulted in the lowest rise in malondialdehyde (MDA) from booting to grain filling stage. With the progression of plant age the peroxidase (POX), ascorbate peroxidase (APX) and catalase (CAT) enzyme activity declined. The water deficit stress induced greater increase in POX and APX activity in tolerant variety. Si + Dr treatment was able to counter the decline caused in CAT activity due to the implication of water deficit stress. Overall, the silicon treatment reduced the oxidative stress.