Alleviation of osmotic stress effects by exogenous application of silicon nutrient on sugarcane seedlings

Abstract

The aim of the study was to assess the role of calcium silicate in osmotic stress tolerance in sugarcane seedlings. This was accomplished by determining the impact of the acids applied exogenously on seedlings grown under osmotic stress in hydroponics. Sugarcane clone was grown in a hydroponic system, and the effect of calcium silicate supplied to the nutrient solution under osmotic stress was investigated. The results showed that osmotic stress reduced all growth variables in this clone, but silicate supplementation, however, partly overcame this growth reduction. Net photosynthesis, chlorophyll content, stomatal conductance and transpiration were higher in plants under control treatment, and silicate in the nutrient solution resulted in a slight increase in these plant parameters. Intercellular carbon-di-oxide was slightly higher in plants under silicate treatment than in plants under control or polyethylene glycol (PEG 6000) treatment. The results suggested that, in hydroponically grown plants, the inclusion of silicate in the nutrient solution was beneficial because it improved growth, physiological parameters and might contribute to a more balanced nutrition by enhancing nutrient uptake under polyethylene glycol (PEG 6000)-stressed conditions. Silicon ameliorate, particularly in the tolerant silicon cultivar, the harmful effects and after effects of osmotic stress induced by polyethylene glycol in hydroponics through better osmotic adjustment were achieved by an increase in proline and nitrate reductase content as well as by an increase in antioxidant activity.