红树林对海平面上升的响应机制

Mangrove ecosystem, present at the dynamic interface between land and sea, is a crucial ecological barrier along the coastlines, and plays an important role in global climate changes. Of all the outcomes from global warming, sea-level rise is considered the greatest threat to mangroves. At present, the effects of sea-level rise on mangrove forests mainly focuses on the study of the sediment surface elevation, while the study on the physiological and ecological characteristics of mangrove forests is rarely reported. The knowledge on how mangrove forests feel the threaten from the sea-level rise, how they perceive and adapt to anaerobic stress, and the molecular ecology mechanism behind are almost blank. Therefore, the research on the biological and physiological role of mangrove plants is imminent. In the proposed research, mechanism of mangrove plants adaptation to anaerobic stress, based on tropical and subtropical mangrove ecosystems, will be studied. This project will provide a scientific foundation for sea ecological ecosystem management and the sustainable utilization of biological resources.

红树林生态系统处于海陆动态交界面，是沿海重要的生态屏障，在全球变化过程中扮演着重要的角色。全球变暖导致海平面升高，严重威胁着红树林的生存。目前，海平面上升对红树林的影响主要集中在对红树林沉积物表面高程方面的研究，而对红树林的生理与生态学特征方面的研究较少。红树林是如何感受海平面上升带来的胁迫，对水淹厌氧胁迫的感知与分子生态学适应机制几乎为空白。因此，对于红树植物的生理生化及分子研究工作迫在眉睫。本研究以热带、亚热带红树林生态系统为研究对象，开展红树林对海平面上升响应的厌氧适应机制研究，为我国海洋生态系统的管理和生物资源的可持续利用提供科学依据。

本项目以红树植物秋茄为研究对象，研究红树植物对海平面上升的响应与适应机制。利用转录组测序等分子生物学手段，共鉴定得到2659个差异表达的基因，其中，在水淹缺氧环境胁迫下多达1203个差异基因上调和1456个基因受涝影响下调。结果表明秋茄根部组织的厌氧胁迫应答过程与抗氧化系统、激素信号传导，糖代谢，蛋白内质网降解过程等通路相关。利用RACE技术成功克隆了秋茄厌氧胁迫相关的关键基因乳酸脱氢酶（KoLDH）、丙酮酸脱羧酶 (KoPDC)和过氧化物酶 (KoPOD)并进行功能分析。本项目还成功分离出红树根系微生物的天然代谢产物，具有广谱的抗真菌活性且不影响农作物的生长，在农业病害防治方面具有潜在的应用价值。本项目取得了一系列科研成果，发表论文6篇，申请发明专利2项，参加国内外学术会议3次。