Silicon Alleviates Drought Stress of Sugarcane Plants by Improving Antioxidant Responses

Abstract

Abiotic stress, such as water deficit, is one of the most devastating factors hindering sustainable agricultural crop output today. Plants use their own defensive strategies to cope with the harmful effects of this stress. Silicon is generally considered as a significant element for the growth, development and biomass/ yield production of plants, especially for those grown under stressful environmental conditions. This study was conducted to assess the impact of Si on antioxidant and phytohormones of sugarcane during water deficit. Experiment arranged as a completely randomized block design (CRBD), was used to examine the effects of two irrigation levels (mild -75 and severe stress -30% of FC and six silicon concentrations consisting of 0, 194, 387, 581, 774 and 968mg Si kg -1 soil. Calcium metasilicate (CaO.SiO 2 ) was used as a source of silicon. CaO.SiO 2 addition also enhanced the activities of catalase, peroxidase, superoxide dismutase and phytohormones according to stress intensity and Si doses. The exogenous silicon plays a key role to tolerate water deficit in antioxidant enzymes base, thereby improving overall development and productivity. The results suggest that sugarcane cultivar GT42 is more tolerant to water deficit conditions because of more efficient antioxidant system.