Antioxidant enzyme activities in male and female plants of Hippophae salicifolia D. Don in different pheno-phases

Abstract

Changing seasons or environmental condition of a region and various life phases of the yearly cycle of plants can cause the production of reactive oxygen species in plant tissues. The antioxidative system plays a vital role in acclimations in such stress-full conditions, either enzymes or non-enzymatic molecules. Hippophae salicifolia D. Don. is a dioecious and deciduous tree species growing in temperate to the subalpine region of Indian Himalayas in Lahul Spiti (Himachal Pradesh), Uttarakhand, Sikkim, and Arunachal Pradesh. As a dioecious species, variation in male and female was observed in many aspects in both sexual-morph in a range of studies. A hypothesis was made in this study, that male and female plant of H. salicifolia has a different antioxidant potential for quenching the reactive oxygen species in the various growing season of the year, and the antioxidant enzyme activities of male and female also vary with pheno-phases. For this purpose, 10-year-old male and female plants were selected, and leaves and buds were collected from them according to the growing season. Enzymatic extraction was carried out according to the standardized method and enzyme assays were carried out for superoxide dismutase (SOD) and peroxidase (POD). Results showed the variation in SOD and POD enzyme activities in leaves and buds of male and female plants of H. salicifolia in different pheno-phases. Female leaves showed highest enzymatic antioxidant activities in the fruit maturation period (September) and lowest during leaf senescence period (November), whereas male leaves showed highest SOD activity in September but highest POD activity in July. Buds showed higher SOD activity, but lower POD activity than the leaves and differences in activity was not significant in dormant buds at gender basis, active buds showed lower SOD activity but higher POD activity in both male and female.