Effect of potassium silicate on reduction of boron accumulation and oxidative damages in grape (Vitis vinifera cv. ‘Bidaneh Sefid’) under boron toxicity stress

Stress induced by boron toxicity is one of the main problems in the arid and semi-arid area. One of the methods for increasing plant resistance to abiotic stresses is silicon treatment. In order to study the effect of silicon on boron toxicity reduction in ‘Bidaneh Sefid’ grape saplings, an experiment was conducted with three concentrations of boron (0.2, 15 and 30 mg/l) and potassium silicate (0, 50 and 100 mg/l) in factorial arrangement based on randomized complete block design with three replications. Three months after the treatments, accumulation of boron, relative water content, ion leakage, proline, malondialdehyde, soluble sugars, soluble protein and guaiacol peroxidase enzyme activity was measured. The results showed that accumulation of boron, ion leakage, proline and malondialdehyde content, soluble sugars and total soluble protein of leaves increased with increasing boron concentration but relative water content and guaiacol peroxidase enzyme activity decreased. Potassium silicate application significantly reduced the accumulation of boron, malondialdehyde content and ion leakage in leaves and increased guaiacol peroxidase enzyme activity and leaf relative water content. None of the treatments had a significant effect on soluble sugar content. Boron accumulation in 30 ppm boron treatment was decreased 33 mg per kilograms dry weight by 100 mg/l potassium silicate application compared to the same treatment with zero ppm potassium silicate concentration. The results showed that grape saplings treatment with 100 mg/l potassium silicate alleviates oxidative damage caused by boron toxicity by reducing boron accumulation in leaves.