三角褐指藻和小角毛藻对UV-B辐射增强的生理生化响应

Physiological and biochemical responses of Phaeodactylum tricornutum and Chaetoceros minutissimus to enhanced UV-B irradiation

通过实验生态学和生物化学的方法,研究了UV-B辐射对三角褐指藻和小角毛藻的生长、叶绿素a、类胡萝卜素、丙二醛、可溶性蛋白含量和抗氧化物酶活性的影响。结果表明:(1)UV-B辐射增强抑制了2种微藻的生长,低剂量(0.75J/m2)UV-B辐射对三角褐指藻的生长具有一定刺激作用。(2)三角褐指藻的叶绿素a含量随辐射剂量的增加先上升后下降,小角毛藻chl-a含量缓慢下降。2种微藻MDA含量随UV-B辐射剂量的增加而升高。(3)随着辐射剂量的增加,三角褐指藻可溶性蛋白含量先稍有升高后较快下降。小角毛藻可溶性蛋白含量始终呈下降趋势。(4)UV-B辐射增强使2种微藻的SOD、POD和CAT活性先升高后下降,小角毛藻的酶活性变化相对稳定。

The effects of UV-B irradiation on the growth,physiological and biochemical characteristics including chlorophyll,Car,MDA,soluble protein contents and antioxidant enzyme activity of Phaeodactylum tricornutum and Chaetoceros minutissimus were studied by using experimental ecology and biochemical methods. The results are as follows.（1） UV-B irradiation could inhibit the growth of two marine microalgae species; however,low-dose of UV-B irradiation（0.75 J/m2） could stimulate the growth of P.tricornutum.（2） Two microalgal species exposed to UV-B radiation had lower content of chlorophyll than the control. The chlorophyll content of P. tricornutum increased first and then decreased; C. minutissimus showed a decreasing trend with increasing dose of UV-B radiation. The MDA contents of two microalgal species increased with increasing dose of UV-B radiation.（3） The soluble protein content of P. tricornutum under enhanced UV-B irradiation increased first and then decreased; C. minutissimus showed a decreasing trend from the beginning to the end.（4） The SOD,POD and CAT activities of two marine microalgae increased first and then decreased,whereas C. minutissimus showed a relatively stable change under UV-B irradiation.