In order to study the effects of drought at different days on biochemical characteristics of two rose species, a factorial experiment based on randomized complete design with three replications was conducted. Two rose species (damask rose and dog rose) were irrigated at three levels (25, 50 and 100% field capacity, FC) at 1, 3, 6 and 12 days. The results showed that content of amino acids (except tryptophan and histidine) increased at 50 and 25% FC from 1 to 12 days in both species. In 50 and 25% FC treatments relative water content decreased and ion leakage increased from 1 to 12 days in both species. Biomarkers of hydrogen peroxide and malondialdehyde increased from 1 to 12 days in both species at both drought levels. Furthermore, the antioxidant enzyme activity of catalase, peroxidase and superoxide dismutase was enhanced in both species from 1 to 12 days in 50 and 25% FC treatments. Chlorophyll content increased at both drought levels from 1 to 12 days in both species. The content of amino acids and the antioxidant enzyme activity in damask rose was higher than dog rose, while the accumulation of malondialdehyde, hydrogen peroxide, ion leakage and chlorophyll content in dog rose was higher than damask rose under drought stress.
Keywords: antioxidant enzymes, amino acid, stress, osmolytes, rose