Metabolomic analysis indicates a pivotal role of the hepatotoxin microcystin in high light adaptation of Microcystis
Metabolomic analysis indicates a pivotal role of the hepatotoxin microcystin in high light adaptation of Microcystis
复制标题
DOI：
10.1111/1462-2920.12565
复制
发表时间：
2015-05-01
影响因子：
5.1
通讯作者：
Dittmann, Elke
中科院分区：
文献类型：
--
作者：
Meissner, Sven;Steinhauser, Dirk;Dittmann, Elke
微囊藻是一种淡水蓝藻，经常在夏季形成令人讨厌的水华。该属属于强效肝毒素微囊藻毒素的主要生产者。微囊藻的成功及其对强光条件的显著抗性尚不清楚。在这里，我们使用GC/MS-based代谢组学方法比较了铜绿微囊藻（Microcystis aeruginosaPCC7806）及其微囊藻毒素缺陷mcyB突变体（Mut）和蓝藻模式生物SynechocystisPCC6803对250摩尔光子（-2）s（-1）的高光照射的代谢反应。野生型微囊藻和Mut型微囊藻在高光下的代谢重编程表现出明显的差异。在强光照射后，检测到的代谢物中有17%在两种基因型之间显示出显著差异。而产生微囊藻毒素的野生型在高光照射下显示出更快的乙醇酸积累，微囊藻毒素的损失导致一般胁迫标记物如海藻糖和蔗糖的积累。该研究进一步揭示了形成华花的蓝藻微囊藻和模式蓝藻聚囊藻在强光适应方面的差异。最值得注意的是，微囊藻在强光照射后投入更多的碳储备，如糖原。我们的数据对开花形成蓝藻的生活方式，广泛存在的毒素微囊藻毒素的作用和蓝藻的代谢多样性的新光。
Microcystis is a freshwater cyanobacterium frequently forming nuisance blooms in the summer months. The genus belongs to the predominant producers of the potent hepatotoxin microcystin. The success of Microcystis and its remarkable resistance to high light conditions are not well understood. Here, we have compared the metabolic response of Microcystis aeruginosaPCC7806, its microcystin-deficient mcyB mutant (Mut) and the cyanobacterial model organism SynechocystisPCC6803 to high light exposure of 250molphotonsm(-2)s(-1) using GC/MS-based metabolomics. Microcystis wild type and Mut show pronounced differences in their metabolic reprogramming upon high light. Seventeen percent of the detected metabolites showed significant differences between the two genotypes after high light exposure. Whereas the microcystin-producing wild type shows a faster accumulation of glycolate upon high light illumination, loss of microcystin leads to an accumulation of general stress markers such as trehalose and sucrose. The study further uncovers differences in the high light adaptation of the bloom-forming cyanobacterium Microcystis and the model cyanobacterium Synechocystis. Most notably, Microcystis invests more into carbon reserves such as glycogen after high light exposure. Our data shed new light on the lifestyle of bloom-forming cyanobacteria, the role of the widespread toxin microcystin and the metabolic diversity of cyanobacteria.