Silicon attenuates abiotic stress caused by ammonium toxicity but not nitrogen deficiency in cotton plants
Aguinaldo José Freitas Leal, Rafael Ferreira Barreto, Renato de Mello Prado, Gabriel Barbosa da Silva Júnior, Cláudio Ferreira Barreto, Luiz Cláudio Nascimento dos Santos, Cid Naudi Silva Campos
Abstract
Abstract Although predominates in many soils, compared to , the fluctuations in the forms and concentrations of N can expose to N deficiency in plants in general and toxicity in sensitive plants. However, a strategy to mitigate nutritional disorders of N is to utilize Si. We aimed to verify if Si attenuates N deficiency and toxicity in cotton plants grown in nutrient solution. The treatments followed a 5 × 2 factorial scheme, with five concentrations of (1.0; 7.5; 15.0; 22.5 and 30.0 mmol/L) combined with the absence and presence of Si (1 mmol/L), arranged in a completely randomized design with four replications. Without Si, the largest shoot dry mass occurred at 16 mmol/L , increased by 47%, compared to 1 mmol/L and decreased by 37% compared to 30 mmol/L . With Si, the largest shoot dry mass was observed at 20 mmol/L , increased by 52% compared to 1 mmol/L and decreased by 14% compared to 30 mmol/L . In addition, in the highest concentration of , plants with Si exhibited a higher shoot dry mass relative to plants with no Si supplementation due to decreased electrolyte leakage index and increased use efficiency of N and K. Cotton plants were tolerant to high concentrations (≈15 mmol/L). Si attenuates abiotic stress caused by toxicity (30 mmol/L) but not N deficiency in cotton plants.