紫外辐射(UVB)胁迫下南极硅藻Phaeodactylumtricornutum ICE-H的生理生化与抗氧化活性响应

Physiological,Biochemical and Antioxidant Activity Response of Antarctic Diatom Phaeodactylum tricornutum ICE-H Under Ultraviolet Radiation(UVB)Stress

对分离自南极海冰的南极硅藻Phaeodactylum tricornutum ICE-H实施一定强度的中波紫外线(UVB)(70μw/cm2)辐射(0~7 d),研究了其生理生化指标的变化情况,并了解了UVB辐射对其生长及生物组成的影响。结果表明:(1)在UVB胁迫下,该南极硅藻生长速率下降,干重减少,总蛋白含量降低,总脂含量增加;(2)总单不饱和脂肪酸(MUFA)含量降低,总多不饱和脂肪酸(PUFA)含量升高;(3)叶绿素a、叶绿素b及总叶绿素含量均降低;(4)抗氧化系统作用相应明显,活性氧自由基(ROS)生成速率增加,丙二醛(MDA)大量产生及总超氧化物歧化酶(SOD)大量累积。本研究为进一步认识南极硅藻Phaeodactylum tricornutum ICE-H应对UVB辐射的机理以及南极生态系统对UV-B辐射响应提供启示。

Phaeodactylum tricornutum ICE-H,a diatom isolated from Antarctic sea ice,was subjected to a certain intensity of UVB(70μw/cm2)radiation for 0−7 days,and the changes in its physiology and biochemistry were studied to understand the effect of UVB radiation on its growth and biological composition.The results showed that:UVB stress decreased the growth rate of Phaeodactylum tricornutum ICE-H,decreased dry weight and total protein content of it,and increased total lipid content.Total monounsaturated fatty acid(MUFA)decreased,and total polyunsaturated fatty acid(PUFA)increased.The content of photosynthetic pigments chlorophyll a,chlorophyll b,and total chlorophyll all decreased.The activity of antioxidant system was correspondingly obvious,the generation rate of reactive oxygen species(ROS)increased,malonaldehyde(MDA)produced in a large amount and superoxide dismutase(SOD)accumulated in large quantities.The results of this study can provide further understanding of the mechanism of Phaeodactylum tricornutum ICE-H in response to UVB radiation from the physiological and biochemical level,and provide enlightenment for the response of Antarctic ecosystems to UVB radiation.