Responses of In Vitro Strawberry Plants to Drought Stress under the Influence of Nano-Silicon Dioxide

The aim of the study is to determine the effectiveness of nano-silicon dioxide (NaSiO2) application on the tolerance of strawberry plants exposed to drought stress under in vitro conditions. Drought stress was induced with polyethylene glycol (PEG-6000). In the experiment, the effects of PEG 6000 concentrations (0, 4, 8%) and NaSiO2 concentrations (0, 50, 100 mg L-1) on in vitro strawberry plants were determined. Plants treated with PEG 6000 showed reduced vegetative growth parameters, but this decrease was reduced with NaSiO2 application. The addition of NaSiO2 enhanced shoot and leaf growth, SPAD index, and the leaf relative water content (LRWC) of in vitro strawberry plants. NaSiO2 at 50 mg L-1 induced the maximum shoot and root fresh weight (1.20 g, 1.24 g, respectively) and length (40.09 mm, 34.26 mm, respectively), leaves number (16.67 pieces/plant) and SPAD index 53.57 among 4% and 8% PEG applications. When the superoxide dismutase (SOD) and catalase (CAT) activities were examined, the results showed that the application of NaSiO2 enhanced drought stress tolerance by promoting certain antioxidant responses by increasing SOD and CAT activities under drought stress. Our results suggest that the application of NaSiO2 can help maintain the devastating impact of drought stress and markedly enhance all the examined parameters in the Albion strawberry cultivar under in vitro conditions.