现代植物培养实验探索二叠纪‒三叠纪大灭绝事件后陆地植被演替的微生物驱动力 / Modern Climate⁃Controlled Plant Growth Experiments Exploring the Microbial Drivers of Terrestrial Vegetation Succession after the Permian⁃Triassic Mass Extinction

植物通过与微生物共生（如菌根真菌与固氮细菌），增强自身对矿物质营养元素与水分的吸收能力，提高对极端气候的耐受性. 尽管植物‒微生物共生作用的意义重大，但由于化石难以保存，地球历史关键气候转折期中有关植物与微生物共生关系的直接证据较为 稀缺 .以二叠纪‒三叠纪生物大灭绝期间残存植物的现代亲缘种为研究对象（异叶南洋杉 Araucaria heterophylla、福建苏铁 Cycas revoluta和银杏Ginkgo biloba），通过设置人工气候植物培养箱组的温度，进行一年的培养，通过高通量扩增子测序分析这些植物根系 微生物的群落组成和相对丰度变化，与化石记录的植物演化过程对比，探索三叠纪极端温室气候下微生物与植物相互作用关系对植物 生存的影响.初步结果表明，在常温25 ℃的基础上升高10 ℃后，南洋杉根际微生物中有益和有害微生物的相对丰度比例高于苏铁和银 杏，这可能是南洋杉这类松柏类植物能在早三叠世极端高温环境中成为主要类群的原因之一 .然而，随着培养温度降低至 30 ℃和 25 ℃，苏铁和银杏根际微生物的表现更为优越，分别在稍冷的晚三叠世及之后的群落中占据优势地位 .本研究从微生物的角度揭 示了二叠纪‒三叠纪大灭绝后植物适应极端温室气候的机制，为理解深时植物‒微生物‒环境相互作用提供了重要数据支撑 .

Plants enhance their nutrient and water uptake and improve resilience to extreme climates through mutualism with microorganisms, including mycorrhizal fungi and nitrogen-fixing bacteria. Despite the ecological significance of plant-microbe interactions, direct evidence of such symbioses during critical climate transitions in Earth’s history remains limited due to the lack of relevant fossil records. This study adopts a modern-analogue approach, focusing on extant relatives of plants that survived the Permian-Triassic mass extinction, including Araucaria heterophylla, Cycas revoluta, and Ginkgo biloba. Using artificial climate chambers with temperature gradients, these plants were cultivated for one year, and high-throughput amplicon sequencing was employed to analyse the composition and relative abundance of root-associated microbial communities. The findings were then compared to plant fossil evidence to explore the impact of plant-microbe symbioses on plant survival under the extreme greenhouse climates of the Triassic. Preliminary results indicate that increasing the temperature by 10 °C above 25 °C resulted in a higher relative abundance ratio of beneficial and harmful microorganisms in the rhizosphere of Araucaria compared to Cycas and Ginkgo. This may explain why coniferous plants like Araucaria became dominant during the high-temperature conditions of the Early Triassic. However, at lower temperatures (30 °C and 25 °C), the microbial communities associated with Cycas and Ginkgo exhibited greater adaptive advantages, consistent with their later dominance in cooler Late Triassic and post-Triassic ecosystems. This study provides microbial-based insights into the mechanisms by which plants adapted to extreme greenhouse climates following the Permian-Triassic mass extinction and contributes valuable data for understanding deep-time plant-microbe-environment interactions.