Hormonal responses of wild and cultivated barley genotypes to cadmium stress

Contamination of agricultural soils with heavy metals, including cadmium, has been increasing in recent years and has caused serious problems for the production and safety of agricultural products in these contaminated areas. The objective of present study was to evaluate and contrast the effects of cadmium (Cd) toxicity on growth and hormonal response of wild and cultivated (Zehak) barley genotypes. Plants were subjected to different levels of Cd concentrations including ۰ (control) and ۱.۵ mg g-۱ in soil. Cd treatment led to accumulation of Cd in shoot and reduction of dry weight in both genotypes. Content of stress related hormones including abscisic acid, jasmonic acid and ethylene significantly increased as compared with control group. Under Cd stress, ethylene content of cultivated genotype was significantly higher than wild genotype. The content of kinetin hormone significantly decreased in response to Cd stress in both genotypes. Significant decrease in auxin content under Cd toxicity was only observed in cultivated barley genotype. In both genotypes, gibberellic acid content did not affect by Cd stress. Based on these results, during cadmium stress, changes in stress-related hormones can induce appropriate stress responses in barley genotypes. On the other hand, the decrease in growth hormones such as kinetin can contribute in growth retardation observed under cadmium stress.

کلیدواژه ها:

Abscisic acid ، Auxin ، Cytokinin ، Ethylene ، Heavy metals ، Jasmonic acid