Salicylic acid modulates accumulation of Cd in seedlings of Cd-tolerant and Cd-susceptible soybean genotypes

Abstract

The seedlings of Cd-tolerant (Balkan) and Cd-susceptible (L 608) soybean genotypes were used to investigate the effect of salicylic acid pretreatment (10-5 M) on Cd toxic action. Cadmium-induced leaf desiccation, chlorophyll degradation, and increase of membrane impairment were more pronounced and partially ameliorated by SA treatment in the Cd-susceptible genotype. Root Cd accumulation was similar in the two genotypes, but SA stimulated Cd accumulation in the tolerant genotype, while in the susceptible genotype this accumulation was inhibited by SA. The Cd-tolerant Balkan genotype was apparently characterized by more efficient control of the oxidative stress induced by Cd, so it did not trigger mechanisms preventing further uptake of this heavy metal. It appears that differences between the genotypes with respect to Cd-tolerance occurred due to different degrees of efficiency of nonspecific defense mechanisms involving salicylic acid as a signal molecule.