Effect of salicylic acid on chlorophyll and carotenoid contents of wheat and moong seedlings

With the increase in concentration of applied salicylic acid (SA), chlorophyll (Chl) content decreased significantly in both wheat and moong seedlings. Chl a/b ratio decreased significantly only in wheat and remained constant in moong. On the other hand, total carotenoid (Car) content, size of xanthophyll pool, and de-epoxidation rate increased significantly with an increase in SA concentration in both plant species. Hence SA treatment may induce Car biosynthesis in these plant species, but the increase in the xanthophyll pool and de-epoxidation rate indicates that SA may create oxidative stress the degree of which is different in various plants.