热胁对海洋红藻及绿藻叶绿素荧光的影响

Effects of heat stress in marine red and green algae by chlorophyll fluorescence method

目的 :研究热胁对红藻带形蜈蚣藻和绿藻孔石莼叶绿素荧光的影响 ,探讨其作用机制 .方法 :采用叶绿素荧光动力学和荧光光谱的方法 ,测定 4 0℃下海藻叶绿素荧光随处理时间的变化 .结果 :带形蜈蚣藻的叶绿素荧光动力学曲线随受热时间呈规律性的变化 ,荧光强度先下降后上升 ,并有荧光的骤升现象 ,在达到最大值后 ,荧光就逐步跌落且不可逆转 .此时藻体的荧光光谱发生了显著变化 ,藻红蛋白的发射峰升高而藻蓝蛋白的发射峰下降 ,表明激发能从前者向后者的传递受阻 .孔石莼的荧光动力学曲线没有骤升现象 ,且受热过程中 ,藻体的荧光光谱没有显著变化 .结论 :热胁对两种海藻的作用机制不全相同 .

Aim: To investigate the effect of heat stress on two marine algae Grateloupia turuturu Yamada (red alga) and Ulva pertusa Kjellm (green alga), and study the action mechanism of heat stress on seaweeds. Methods: Chlorophyll (chl) fluorescence induction kinetics and fluorescence emission spectrum were measured to examine the changes of chl fluorescence in different time of treatment at 40℃. Results: The chl fluorescence induction kinetics of Grateloupia turuturu showed regular changes during the time course of 40℃ treatment, the fluorescence first decreased and then increased, with a 'burst' phenomenon. After reached the maximum value, fluorescence yield decreased and can not be restored. At the same time, the emission peak of phycoerythrin increase while that of phycocyanin decrease, which shows the transfer of excitation energy from phycoerythrin to phycocyanin was blocked. In contrast to Grateloupia turuturu, the chl fluorescence induction kinetics of Ulva pertusa didn't have 'burst' phenomenon, the fluorescence emission spectra didn't show marked changes during the time course of heat treatment. Conclusion: The mechanisms of heat stress on the two algae were different.