微囊藻毒素介导的群体微囊藻细胞间信号传导机制研究

Frequent and large-scale outbreaks in Microcystis blooms have become one of the major environmental problems in China. The formation and colony morphology of microcystis is an important prerequisite for its population advantage and thus the formation of algal blooms. Therefore, understanding of the mechanism of colonial microcystis formation will help to reveal the mechanism of cyanobacterial bloom. This project is intended microcystin as a signal molecule to explore its role in microcystis - microcystis communication. The main contents are involved: 1）the physiological response of microcystis and adhesion bacteria with low dose microcystin treatment; 2) the relationship between microcystin production and Microcystis cell density; 3) comparison of related gene expression in Microcystis on logarithmic growth phase and cell density reached a certain threshold; 4) the intrinsic regulation between microcystins and related binding proteins. The aim of this project is to explore the internal mechanism on microcystin-mediated signal transduction between Microcystis cells as a signaling molecule from the physiological ecology and molecular biology. This study will provide an important theoretical basis for in-depth understanding of Microcystis colony formation and water bloom formation.

微囊藻水华的频繁、大规模暴发已成为我国重大的环境问题之一，而微囊藻群体的形成及形态的持久维持是其获得种群优势进而形成水华的重要前提，因此，对微囊藻群体形成机理的认识将有助于揭示蓝藻水华暴发的机理。本项目拟从微囊藻毒素作为信号分子入手，探讨其在微囊藻细胞间信号传导的作用，通过环境剂量微囊藻毒素对群体微囊藻及微囊藻黏附细菌的生理响应、微囊藻毒素的产生与群体微囊藻细胞密度的关系、群体微囊藻对数生长期及细胞密度达到一定阈值时相关基因表达的比较、微囊藻毒素与相关结合蛋白的内在调控等研究，从生理生态学及分子生物学角度探讨微囊藻毒素作为信号分子调控微囊藻细胞间信息传递的内在机制。本项目的研究为深入认识微囊藻群体形成和水华暴发机理提供重要理论依据。

微囊藻水华的频繁、大规模暴发已成为我国重大的环境问题之一，其中微囊藻毒素尤其受到关注。而有关微囊藻毒素的生态学功能研究相对薄弱，本项目以微囊藻毒素作为信号分子入手，探讨其在微囊藻细胞间信号传导的作用，主要研究结果：1. 产毒微囊藻和微囊藻毒素降解细菌相互影响，微囊藻毒素降解细菌可能调节水华过程中产毒与非产毒微囊藻种群的转变；2. 滇池水体中的束丝藻是主要的潜在ATX –a产生者，主要出现在早春，而温度变化可能是影响束丝藻演替的驱动因素之一； 3. 通过对半连续培养样品进行液相质谱检测，共鉴定到11种可能与微囊藻毒素特异性结合的蛋白，分别涉及蛋白质合成，碳代谢，氨基酸合成，叶绿素合成和硫代谢等细胞内重要的代谢过程，表明结合态微囊藻毒素在藻生长过程中可能具有重要作用；4. 在评价水体中微囊藻毒素时，不仅考虑游离的微囊藻毒素，与蛋白结合的微囊藻毒素也应纳入评价范畴。本项目的研究为深入认识微囊藻群体形成和水华暴发机理提供重要理论依据。