高寒草甸植物抗氧化系统对长期增强UV-B辐射的响应

通过研究自然条件下模拟平流层臭氧破坏5%时近地表面增加的太阳UV-B辐射对高寒草甸4种典型植物(矮嵩草Kobresia humilis、垂穗披碱草Elymus nutans、麻花艽Gentiana straminea和鹅绒委陵菜Potentilla anserina)的抗氧化系统的影响表明,尽管各植物的抗氧化系统组分变化不同,但4种植物的膜脂过氧化程度没有加剧,长期增强UV-B辐射没有对膜系统造成损伤.在自然长期增强UV-B条件下,4种植物的膜脂过氧化产物--丙二醛(MDA)含量与对照相比无显著差异.垂穗披碱草、鹅绒委陵菜的谷胱甘肽(GSH)含量增加,麻花艽的超氧化物歧化酶(SOD)活性与鹅绒委陵菜的过氧化氢酶(CAT)活性上升,同时麻花艽的类胡萝卜素(Car)含量亦显著增加.可见这些植物已能很好地适应UV-B强辐射,其抗氧化能力除了与抗氧化系统各组分的协同作用有关外,也可能与种的适应性有关.

Responses of the antioxidative system of pants in alpine meadow to long-term UV-B radiation

The effects of long-term intensified UV-B radiation on the antioxidant systems of four plants(Kobresia humilis,Elymus nutans,Gentiana straminea,Potentilla anserina) grown in alpine meadow was investigated,and stimulating a 5% ozone depletion in this region by supplementing UV-B radiation in the growth season.The results suggested that the membrane system of the plants was not injured although variation of the antioxidant system among four plants was different.Under long-term intensified UV-B radiation,the contents of MDA in four plants had no significant difference compared with the control.The contents of GSH in E.nutans and P.anserina increased as same as the contents of Car in G.straminea,meanwhile,superoxide dismutase(SOD) activities of G.straminea and catalase(CAT) activities of P.anserine elevated.It could be concluded that the cooperation of the antioxidant system proportions in the four plants was vital to their adaptation under long-term intensified UV-B radiation.