细胞质HSP70和HSP90基因结构及拷贝数与甲藻温度耐受性的相关性研究

In the last three decades, the frequency of dinoflagellate blooms increased in global ocean, and it could be worse in the future. These phenomena are likely close related to the increasing ocean temperaure under the background of climate change. The harmful algal bloom (HAB) causative species that with proper thermal niche could be adaped to the increasing ocean temperature and cause the HABs. The thermal niche of these HAB causative species should be determined by the genes involved in the temperature adaption process. The cytosolic heat shock protein 70 (HSP70) and heat shock protein 90 (HSP90) are genes that are widely involved in the temperature stress resistance in various organisms. Some of evidences have implied that the cytosolic HSP70 and HSP90 responded to temperature stress in dinoflagellates, and the gene structure and copy numbers of them might quite differ among species. However, the correlation of the gene structure and copy numbers of cytosolic HSP70 and HSP90 and thermal niche of dinoflagellates are still unknown. On the basis of our previous works, the gene structure, copy numbers and the expression patterns of cytosolic HSP70 and HSP90, and thermal niche of various causative dinoflagellates of HAB will be determined in this project. Furthermore, the correlation of gene structure, copy numbers of cytosolic HSP70/HSP90 and thermal niche of dinoflagellates will be analyzed. The results will provide the scientific evidence for in-depth revealing the HAB expanding mechanism in the context of climate change, and might also provide the scientific data for developing the new methods of forecasting and monitoring of HAB in the future.

近30年来全球有害甲藻藻华呈现扩张趋势，并预测在未来可能会更加严重。这种现象的发生与气候变化背景下的海洋温度升高可能密切相关，具有相应温度耐受性的有害藻华原因种，更能适应海洋温度的升高而引发藻华，这必然与一些调控温度耐受性的基因相关。热激蛋白70（HSP70）和热激蛋白90（HSP90）是与生物体适应温度变化密切相关的基因，研究数据表明细胞质HSP70和HSP90在一些甲藻中能被温度所调控，而它们在不同甲藻间的基因结构以及拷贝数可能差异较大，但这种差异性是否与甲藻温度耐受性相关，尚不明晰。本项目拟通过研究多种甲藻藻华原因种细胞质HSP70和HSP90基因的结构、拷贝数和不同温度下的表达模式，以及目标甲藻的温度耐受性，解析细胞质HSP70和HSP90基因结构及拷贝数与甲藻温度耐受性的关系，为深度揭示气候变化背景下甲藻藻华扩张机制，及为未来开发有害藻华预测和预警的新方法提供科学依据。

近30年来全球有害甲藻藻华呈现扩张趋势，并预测在未来可能会更加严重。这种现象的发生与气候变化背景下的海洋温度升高可能密切相关，具有相应温度耐受性的有害藻华原因种，更能适应海洋温度的升高而引发藻华。热激蛋白70（HSP70）和热激蛋白90（HSP90）是与生物体适应温度变化密切相关的基因，它们在不同有害甲藻原因种之间的差异性以及在温度适应性中的作用尚不明晰。本项目测定了多种有害藻华原因种在不同温度下的生长速率以及温度耐受范围，揭示了他们的最适生长温度以及温度耐受范围；测定了多种甲藻的HSP70和HSP90基因的拷贝数，并研究了拷贝数和温度耐受性之间的关系,以及它们在甲藻经过长期温度适应后的转录表达差异。研究结果显示HSP70和HSP90的拷贝数在甲藻中普遍较高，拷贝数可从几百到数百万拷贝，相关性分析显示基因拷贝数与温度耐受性之间的关系相关性较弱，HSP70和HSP90的拷贝数与基因组大小关系更为密切；转录组分析显示HSP70和HSP90多种转录本可应答于长期温度变化，但不同拷贝间的表达差异显著。研究结果表明，甲藻具有较高的HSP70和HSP90基因拷贝数，且它们在温度适应过程中发挥着重要的调控作用。