Effect of seed priming with salicylic acid on physiological and morphological characteristics of maize seedlings under cadmium stress

Cadmium is a toxic element which due to its great cumulative potential in plant organs causes important morphological and physiological changes in plant structure. In order to study of effect of salicylic acid priming on reduction of chloride cadmium damage on maize seedlings, a factorial experimental based on completely randomized design with three replications was conducted at the research laboratory of University of Damghan during 2012. The experiment consisted of two factors including a salicylic acid application (application and no application) and different CdCl2 concentrations (0, 0.05, 0.1 and 0.2 mM). The results showed that increase of CdCl2 concentration resulted in reductions in photosynthesis pigments, anthocyanin and morphological characteristics of maize seedlings. However, MDA, proline and phenolic compounds of maize seedlings were increased as CdCl2 concentration increased. Priming with salicylic acid increased photosynthesis pigments, anthocyanin, phenolic compounds, proline and morphological characteristics and decreased MDA in maize seedlings compared with the control (no application of salicylic acid). Salicylic acid application at the highest concentration of CdCl2 (0.2 mM) increased chlorophyll b, carotenoid, phenolic compounds of shoot and root as 8.24, 19.64, 29.13 and 47.05%, respectively, compared to the control. This reduced the MDA of shoot and root as 27.04 and 16.19%, respectively.