Kumari Rima, Singh Suruchi, Agrawal S B
Laboratory of Air Pollution and Global Climate Change, Department of Botany, Banaras Hindu University, Varanasi--221 005, India.
J Environ Biol. 2010 Nov;31(6):907-11.
Ultraviolet-B (UV-B) radiation generates an oxidative stress in plant cells due to excessive generation of reactive oxygen species (ROS). ROS can denature enzymes and damage important cellular components. In the present study, an important medicinal plant Acorus calamus (Sweet flag) was subjected to two doses of supplemental UV-B radiation (sUV-B): sUV1 (+ 1.8 kJ m(-2) d(-1)) and sUV2 (+3.6 kJ m(-2) d(-1)) to evaluate the relative response of antioxidant defense potential. Stimulation of activities of superoxide dismutase (SOD), catalase (CAT), ascorbate peroxidase (APX) and glutathione reductase (GR) was observed at initial growth period while the activities of CAT and SOD decreased at later age of sampling. sUV-B induced lipid peroxidation (LPO) was observed showing alteration of membrane properties. No definite trend of change was observed for ascorbic acid (AsA), while increments in thiol, proline, phenol and protein contents were observed due to sUV-B. Results suggested that sUV-B radiation may stimulate the enzymatic and non-enzymatic defense system of Acorus plants, showing its better adaptation at lower dose of sUV-B.
紫外线B（UV-B）辐射会因活性氧（ROS）的过度产生而在植物细胞中引发氧化应激。ROS会使酶变性并损害重要的细胞成分。在本研究中，一种重要的药用植物菖蒲接受了两种剂量的补充UV-B辐射（sUV-B）：sUV1（+1.8 kJ m(-2) d(-1)）和sUV2（+3.6 kJ m(-2) d(-1)），以评估抗氧化防御潜力的相对响应。在初始生长阶段观察到超氧化物歧化酶（SOD）、过氧化氢酶（CAT）、抗坏血酸过氧化物酶（APX）和谷胱甘肽还原酶（GR）的活性受到刺激，而在采样后期CAT和SOD的活性下降。观察到sUV-B诱导的脂质过氧化（LPO），表明膜性质发生了改变。抗坏血酸（AsA）未观察到明确的变化趋势，而由于sUV-B，硫醇、脯氨酸、酚类和蛋白质含量有所增加。结果表明，sUV-B辐射可能刺激菖蒲植物的酶促和非酶促防御系统，表明其在较低剂量的sUV-B下具有更好的适应性。
