Potassium silicate counteracts salt-induced damage associated with changes in some growth characteristics, physiological, biochemical responses, and nutrient contents in two grapevines (Vitis vinifera L.) cultivars

Abstract

This study investigates the effects of potassium silicate on the growth characteristics, physiological parameters, biochemical parameters, and nutrient content of two grapevine cultivars, 'Bidaneh Ghermez' and 'Sahibi Gird', under NaCl stress conditions. The plants were exposed to NaCl solutions with concentrations of 0, 40, and 80 mM in a hydroponic system. Additionally, the plants were treated with potassium silicate sprays at concentrations of 0, 50, 100, and 200 mg L^-1. As NaCl levels increased, both 'Bidaneh Ghermez' and 'Sahibi Gird' cultivars exhibited reduced fresh and dry root weights. However, with potassium silicate application at 200 mg L^-1, the rate of root dry weight loss was reduced to 28% and 66.4% for 40 mM and 80 mM NaCl treatments, respectively. The maximum total protein content (1.65 mg L^-1 fresh weight) was detected at the 80 mM NaCl level and potassium silicate application at 50 mg L^-1. The maximum ascorbate peroxidase activity was observed at a potassium silicate concentration of 50 mg L^-1. Based on the results, increasing NaCl levels significantly boosted plant Na⁺ percentage. In treatments with 40 and 80 mM NaCl (without potassium silicate), nitrate levels decreased by 32.34% and 46.71%, respectively, compared to the control. The amount of leaf iron in the 40 mM salinity treatment increased and by 10.47% with potassium silicate at a concentration of 200 mg L^-1. The findings confirmed the role of potassium silicate in modulating the negative effects of NaCl, although more investigations in different grapevine cultivars under NaCl stress are required in this field.