The Protective Role of Silicon in Sugarcane Under Water Stress: Photosynthesis and Antioxidant Enzymes

Abstract

To assess how silicon improves plant growth-development and productivity under water stress, we investigated the photosynthetic and biochemical activities of sugarcane cultivar GT 42 to Si application. Two water regimes [70 and 30% of soil available water content] and six silicon levels, i.e. 0, 20, 40, 60, 80 and 100g Si pot-1, respectively, were applied. This experiment was maintained in a completely randomized block design. The losses in photosynthetic and biochemical parameters due to water stress were alleviated by Si application. The Si application improves the plant growth and development under stress, accompanied with the up-regulated in photosynthesis (~6-39 & 2-93%), stomatal conductance (14-43 & 20-113%), transpiration rate (~19-40 & 24-275%), photosynthetic pigments such as Chl a (~2-12 & 3-25%), Chl b (~10-26 & 12-35%), Chl a+b (6-16 & ~2- 28%), relative water content (~3-5 & 4-8%) and biochemical activities, i.e. catalase (22- 57 & ~24-91%), peroxidase (~8-31 & 15-24%) and superoxide dismutase (~33-44 & 47- 96%). These results improved our understanding of the physio-biochemical mechanisms that underlie the silicon-induced enhances in sugarcane under water stress.