蓝藻CO2浓缩机制微进化差异及其对CO2的响应和种群演替的影响-以微囊藻为例

由于环境的敏感性及代时的短期性，蓝藻常能根据环境变化形成表型可塑性或基因快速进化。因此，蓝藻基因的微进化对CO2变化响应及其导致的种群演替是一个值得关注且有意义的问题。本项目拟以常见的水华蓝藻-微囊藻为研究对象，首先分析不同个体微囊藻的二氧化碳浓缩机制（CCM）基因多样性差异，探讨微囊藻CCM的微进化差异；在此基础上，通过室内模拟条件研究CO2浓度变化对不同CCM基因型个体的生理和竞争影响，探讨微囊藻CCM的微进化差异对CO2的响应导致的种间竞争效应；最后，通过野外微囊藻水华动态和水质参数原位监测，分析微囊藻形态型和CCM基因型的时空变化特征及相互关系，探讨微囊藻CCM微进化对CO2的适应并导致微囊藻种群发生演替的影响机制。研究结果不仅从个体和种群层面揭示CO2变化可能诱导蓝藻发生进化适应，引起蓝藻水华种类和基因型组成发生改变，而且也为阐明全球变化对蓝藻水华发生及演替的影响提供重要依据。

Because of their rapid generation times and environmental sensitivity, cyanobacteria always have substantial capacity for phenotypic plasticity and rapid evolutionary responses to environmental change. Therefore, it is a matter of concern and significance that how the microevolutionary in cyanobacterial gene responses to CO2 changes and results in population succession. A notorious bloom-forming cyanobacterium, Microcysits, is chosen to an object in this project. In this project, it is intended to study genetic diversity in CO2-concentrating mechanism (CCM) of Microcystis to observe their differences in CCM microevolutionary. On this basis, physiological and competition responses to CO2 change in different CCM genotype are also analyzed by laboratory experiments in order to explore the interspecific competition effect caused by microevolution difference of CCM. Meanwhile, to discuss the influence mechanism of CCM microevolution on the succession of Microcystis, the spatial and temporal variation characteristics and the relationship between phenotypic and CCM genotypes were also investigated by in situ monitoring of Microcystis bloom dynamic and water quality parameters. The results will not only reveal that CO2 changes may induce cyanobacteria to undergo evolutionary adaptation to cause changes in species composition and genotypes of cyanobacteria, but also provide an important theoretical basis for clarifying the impact of global change on the occurrence and succession of cyanobacteria bloom.