Effect of two species of mistletoe (Viscum album L. & Arceuthobium oxycedri (D.C.) M. Bieb.) on activity of antioxidant enzyme of infected host species in Gorgan forests

Mistletoe is an evergreen, perennial and epiphytic plant of Loranthaceae which obtains all of its required water and nutrients such as Nitrogen and a small part of the food from the host plant by a root-like organ called "Haustorium". This plant is very important in terms of medical and pharmaceutical and some of its effects in the treatment of many diseases have been proved. Two species of "Viscum album L." and "Arceuthobium oxycedri (D.C.) M. Bieb." both from the family Viscaceae are epiphytic plants. The dominant hosts of Viscum album L. in Gorgan forest are Parrotia persica (D.C.) C.A.Mey and Carpinus betulus L. respectively in altitude of 700 m and 1800m (above sea level). The host of Arceuthobium oxycedri (D.C.) M. Bieb is Juniperus polycarpus L in 2200m (above sea level). In this study, leaves and twigs of mistletoe and the host were collected. Three infected hosts from each species and three uninfected trees as control with similar conditions of diagonal and height were randomly selected, and the effects of these epiphytes on activity of antioxidant enzymes of the host plants, including Catalase, Peroxidase and Ascorbate peroxidase, were studied. The results showed that the infection of epiphyte caused drought stress in host plant and the activity of these enzymes was increased. The activity of Catalase in infected and uninfected hosts of V.album (P. persica and C. betulus) did not show significant differences, but in host of A. oxycedri (J. polycarpus) in male and female trees significant differences were observed. Activity of Ascorbate peroxidase and Peroxidase was significantly increased in all of infected hosts. But in none of the samples, activity of these enzymes was not dependent on the genus.