Foliar application with salicylic acid alleviates cadmium toxicity in chia (Salvia hispanica L.)

Abstract

Cadmium (Cd) accumulation is one of the serious global issues among the multitude of food security challenges. Their toxic effects are evident in different physiological and metabolic behaviors of plants. In this context, a potted study was conducted to investigate the effectiveness of salicylic acid (SA) spraying in alleviating Cd toxicity in chia (Salvia hispanica) seedlings. This pseudocereal as a superfood is characterized by high nutritional value and high therapeutic potential. We examined some growth traits, photosynthetic pigments, anthocyanin, antioxidant defense system, malondialdehyde (MDA), and certain osmoregulatory molecules. The results showed that the chia seedlings exposed to Cd showed a substantial decline in growth, especially in shoot and root length and number of leaves (25.5, 21.5, and 22.6%, respectively), whereas the aforesaid biochemical parameters were not significantly affected. However, SA treatment alleviated the Cd stress applied and markedly enhanced the stem and root growth, especially shoot length of about 32.3% compared to Cd treatment. Under combined treatment Cd+SA, we also recorded a significant increase in the accumulation of proline (85.3%) and anthocyanin (83.1%), and a significant enhancement in peroxidase activity (34.9%), compared to control. These responses exhibit the involvement of SA in mitigating Cd-induced oxidative damage and improving Cd tolerance in Chia. Principal component analysis and cluster analysis showed differences between individual and combined treatment. Based on these results, exogenous SA used in the right amounts could alleviate Cd-induced stress and boost chia seedlings’ growth.