鹿角杯形珊瑚凝集素介导虫黄藻成为内共生体的机制研究

Stony coral forms obligate symbiont with photosynthetic zooxanthellae to adapt to the marine environment and build coral reefs. The symbiosis break-down is mainly caused by some environmental stresses including seawater warming, ocean acidification and human pollution, which has resulted in the bleaching of stony coral and the degradation of coral reef ecosystem. The present research, on the basis of the lectins from coral Pocillopora damicornis, focuses on the establishment mechanism of the symbiosis between stony coral and zooxanthellae. After the mensuration of the recognition activity of the lectins to zooxanthellae, it will be ascertained that the lectins can induce the symbiotic transformation of zooxanthellae stage. The cellular pathway will be explored by which zooxanthellae entre into coral cells and form endosymbiont via lectin mediation, to further understand the regulation effect of the mediation function on the coral physiological activities. The activity of lectins mediating symbiosis and coral physiological changes are determined under elevated temperature, reduced pH and rising nutrient, demonstrating the regulation of the mediation function by environmental factors. Through the combination of multi-omics data and conjoint analysis, the comprehensive interpretation of coral and zooxanthella physiological changes are performed to further reveal the establishment mechanism of the symbiosis. The expected results would contribute to further understand the internal cause of disease outbreaks and consequent death of stony coral which can provide theoretical basis for the conservation of coral reef ecosystem and be helpful for better knowledge of marine biology as well.

造礁石珊瑚通过与虫黄藻形成共生关系来适应海洋环境并建造珊瑚礁。海水升温、海洋酸化和人类污染等环境变化导致了二者共生关系的破裂，从而引起造礁石珊瑚的白化死亡和珊瑚礁生态系统的不断退化。本项目拟采用分子生物学等技术手段，以鹿角杯形珊瑚凝集素为切入点，测定凝集素的虫黄藻识别活性，明确凝集素对虫黄藻共生状态的诱导作用；查明凝集素介导虫黄藻进入珊瑚细胞并成为内共生体的细胞途径，明确该介导作用调控鹿角杯形珊瑚生理的方式；升高温度、降低pH和增加营养盐水平后测定凝集素的共生介导活性和鹿角杯形珊瑚的生理变化，阐明凝集素介导作用的环境调控方式；结合多组学和联合分析，全面解析鹿角杯形珊瑚和虫黄藻的生理变化规律，确定凝集素介导虫黄藻成为内共生体的机制。探索造礁石珊瑚与虫黄藻的共生形成机制，可以揭示造礁石珊瑚因疾病爆发而死亡的根本原因，为珊瑚礁生态系统的保护提供理论基础，并进一步丰富和发展海洋生物学的研究内容。

造礁石珊瑚通过与虫黄藻形成共生关系来适应海洋环境并建造珊瑚礁。海水升温、海洋酸化和人类污染等环境变化导致了二者共生关系的破裂，从而引起造礁石珊瑚的白化死亡和珊瑚礁生态系统的不断退化。本项目综合运用转录组学、分子生物学和细胞生物学方法，查明了3个鹿角杯形珊瑚凝集素的分子特征，测定并比较了其对5种虫黄藻的内共生介导活性，阐明了温度和多糖分子对珊瑚凝集素介导虫黄藻成为内共生体的影响。同时，探究了温度、pH和重金属等环境因子对鹿角杯形珊瑚与虫黄藻共生关系的影响，深入解析了环境变化对鹿角杯形珊瑚与虫黄藻共生生理的影响及其作用机制。相关研究结果探索了造礁石珊瑚与虫黄藻的共生建立机制，从共生关系建立角度揭示了造礁石珊瑚因环境变化而白化死亡的根本原因，为珊瑚礁生态系统的保护提供了理论基础，并进一步丰富和发展了海洋生物学的研究内容。项目执行期间共发表SCI论文17篇，中文核心期刊论文1篇，其中第一标注8篇，第二标注5篇，培养硕士研究生6名。