To understand the impact of climate change on the rhizosphere microecosystems of mangrove plants, this study conducted controlled experiments on the mangrove plant Avicennia marina, in which combined stress was simulated with day/night temperature (control: 28/25°C; extreme low temperature: 8/5°C; extreme high temperature: 40/37°C) and inundation duration (control: 10 h/d; short inundation: 5 h/d; long inundation: 15 h/d). The aim was to explore the response of rhizosphere bacterial diversity, composition, and structure to combined temperature-inundation stress. The results showed that temperature and inundation stress reduced the diversity of rhizosphere bacteria, and extreme high temperature reduced the Chao1 index from 2367.6 to 2017.5 and the Shannon index from 2.40 to 2.11. Principal coordinates analysis revealed that temperature played a primary role in influencing the composition of the rhizosphere bacterial communities in A. marina. Under short inundation, the relative abundance of Gammaproteobacteria was 19%, lower than that of the control group (37%). Temperature and inundation stress significantly reduced the relative abundance of Pseudomonas, while extreme high temperature combined with short or long inundation increased the relative abundance of Geitlerinema. Additionally, compared with inundation, temperature had a greater impact on the rhizosphere community structure of A. marina, and an antagonistic effect existed between temperature and inundation, shifting the rhizosphere bacterial communities from cooperative to competitive interactions. 

为了了解气候变化对红树植物根际微生态系统的影响, 开展红树植物白骨壤(Avicennia marina)的控制实验, 模拟昼夜温度(对照组28/25°C, 极端低温处理8/5°C, 极端高温处理40/37℃)和淹水时间(对照组10 h/d, 短淹水处理5 h/d, 长淹水处理15 h/d)的复合胁迫生境, 探究根际细菌群落多样性, 组成特征和群落结构对温度–淹水复合胁迫的响应规律。结果表明, 温度和淹水胁迫均降低根际细菌多样性, 其中极端高温胁迫降低Chao1指数(从2367.6降为2017.5)和Shannon指数(从2.40降为2.11)。主坐标分析(PCoA)结果表明, 温度对白骨壤根际细菌群落组成的影响起主要作用。短淹水胁迫下的γ-变形菌纲的相对丰度为19%, 低于对照组的37%。温度和淹水胁迫显著地降低假单胞菌属(Pseudomonas)的相对丰度, 极端高温与短、长淹水的复合胁迫增加盖丝藻属(Geitlerinema)的相对丰度。与淹水相比, 温度对白骨壤根际群落结构影响更大, 并且温度与淹水之间存在一定的拮抗作用, 其复合胁迫使根际细菌群落的相互作用模式由协作关系转向竞争关系。