A preliminary investigation on developmental and biochemical responses of Amsonia orientalis to ultraviolet-C irradiation

Abstract

The present study aims to investigate the developmental and biochemical responses of ornamental Amsonia orientalis irradiated with ultraviolet-C (UV-C). Nodal explants of the species were exposed to UV-C irradiation on the first, 15th and the last days of the in vitro culture for 15 (3.47 kJ m-2), 30 (6.94 kJ m-2) and 60 min (13.87 kJ m-2). In general, root lengths and numbers were negatively influenced by prolonged UV-C exposure. However, mean shoot numbers and lengths were slightly enhanced after 15 and 30 min of irradiation. High hydrogen peroxide (H2O2) and malondialdehyde (MDA) levels were observed due to the UV-C exposure. Activities of the antioxidant enzymes, POD (peroxidase) and CAT (catalase) were found to be enhanced whereas SOD (superoxide dismutase) was reduced. These results indicated that UV-C irradiation for shorter durations may be carefully used to improve in vitro shoot proliferation in A. orientalis. However, it should be noted that longer irradiation durations can trigger stress responses and lipid peroxidation-dependent cell membrane damage which will further result in the plant loss.