Assessing the effect of dry season on the activity of antioxidant enzymes of three rangeland species in two southern regions of Iran

  The production of various reactive oxygen species (ROS) is one of the effects of drought stress on plants. In order to combat with them, enzymatic antioxidant is presented in plant cells. In this study, the ability of adaptation of three native rangelands species (Taverniera cunifolia, Lycium shawii and Rhazya stricta) with multiple capabilities such as soil conservation, medicinal and ornamental (green spaces), which are endemic in southern Iran, were studied .The samples were taken random from two habitats in the south of the country (Dehgin basin and Jiroft) and the relative water content (RWC), catalase enzymes, peroxidase and ascorbate peroxidase were measured. Then the results were analyzed by Duncanchr('39')s test. The results showed that the relative water content variable in any of the species had no significant effect and it was concluded that these three species probably have a drought tolerance mechanism. The activity of catalase and ascorbate peroxidase increased in all three species (in two different regions) with significant difference. The activity of peroxidase enzyme in both species R. stricta and L. shawii in both regions increased significantly and decreased in T. cunifolia species. In general, these species as indigenous species in arid regions of the country had the potential to increase antioxidant enzymes, in contrast to drought stress of seasons with less rainfall.  There is also possibility to be used as multifunctional plant species in arid regions with geographical conditions similar to areas studied.