不同Fe~(3+)浓度下赤潮异弯藻对阳光UVR的响应

探讨了不同Fe3+离子浓度环境下,赤潮异弯藻对阳光紫外辐射(ultraviolet radiation,UVR)的响应.结果发现,在Fe3+限制(5×10-3μmol/L)的情况下,阳光紫外辐射的存在,可以提高赤潮异弯藻的生长速率.而在Fe3+饱和(11.65μmol/L)的情况下,这一现象并不明显.说明Fe3+限制培养的细胞,对UVR的敏感性下降.细胞紫外吸收物质(MAAs)的合成受到Fe3+的调节.生长于Fe3+饱和环境下,接受全阳光辐射,胞内MAAs的含量增加明显,抵抗UVR的能力加强,生长加快.因此,赤潮异弯藻对UVR的响应机制,是受到细胞可利用Fe3+浓度调节的.

The response of Heterosigma akashiwo grown under different Fe3+ concentrations to solar UVR

The response of Heterosigma akashiwo grown in media with different Fe3+ concentrations to solar UVR was studied in the present study.The results showed that enhanced growth rate was observed in the cells exposed to solar UVR under Fe~(3+)-limited condition (5×10~(-3) μmol/L).But that could not be detected in the cells grown under Fe~(3+)-saturated condition (11.65 μmol/L).These results indicate that Fe~(3+)-limitation could lower the sensitivity of Heterosigma akashiwo to solar UVR.Moreover, the synthesis of MAAs was found regulated by intracellular Fe~(3+) concentration.Under Fe~(3+)-saturated condition, solar UVR could increase the content of MAAs, and enhance UVR-resistance, thus faster the cell growth rate.Taken together, our results suggest that the response of Heterosigma akashiwo to solar UVR was regulated by the available Fe~(3+) concentration.