Silicon (Si) has been widely reported to alleviate the plant nutrient deficiency, but the alleviating effect of Si on potassium (K) deficiency and its underlying mechanism are poorly understood. Chen et al. investigate the influence of Si on putrescine (Put) metabolism under K deficiency in Sorghum bicolor, and find that Si application could reduce K-deficiency-induced Put accumulation by inhibiting Put synthesis and could decrease H2O2 production via Put oxidation.
Decreased H2O2 accumulation contributes to the alleviation of cell death, thereby alleviating K-deficiency-induced leaf chlorosis and necrosis. The results indicate that Si application could alleviate the K deficiency-induced leaf chlorosis by decreasing H2O2 via inhibiting Put synthesis and oxidation.