铁胁迫诱导的赤潮异弯藻细胞生化组成变化

Induction of biochemical composition in Heterosigma akashiwo under Fe stress

研究了铁胁迫对赤潮异弯藻细胞生化组成的影响 .结果表明 ,铁胁迫下的细胞内所有色素浓度均降低 ,同富铁条件相比 ,铁胁迫下的细胞内叶绿素a浓度降低 2倍多 ,叶绿素c也有相当程度的降低 ,因此 ,铁胁迫下的胞内叶绿素c与叶绿素a的比率变化不大 .铁胁迫下的细胞内类胡萝卜素的含量降低了1.5倍 ,因此在铁胁迫下的细胞内类胡萝卜素相对于叶绿素a的比例升高 ,碳水化合物含量随培养基内铁浓度降低而下降 ,与铁丰富条件 (10 μmol·L-1)相比 ,受铁胁迫的细胞可溶蛋白电泳图谱中 17kDa和 5 5kDa附近的带明显增加 ,而在 2 0kDa和 35kDa附近的蛋白带降低 .

The iron-stress mediated effects on biochemical constituents of red tide alga H. akashiwo were examined in Fe-replete and iron deficiency,and low iron batch cultures. The content of all pigments decreased under iron limitation,and the cellular chlorophyll a concentration decreased by more than 2-fold compared to that under iron replete condition. This change in Chl a was accompanied by a corresponding decrease in Chl c per cell, resulting in no trend in the ratio of Chl c to Chl a. The cellular carotenoids content decreased by more than 1.5-fold compared to that under iron replete condition. As a consequence, carotenoids/chlorophyll a ratio increased in Fe-deficient cells. Carbohydrate content was reduced under iron stress,and total proteins decreased with the decrease of iron concentration. A crude fractionation of the soluble proteins demonstrated that 17 kD and 55 kDa proteins in soluble fraction were induced.