隨著全球暖化越來越嚴重，生長在高山上的植物因為高山的孤立性質，使得植物無法自由離開山區，只能往更高海拔的區域移動。而面對加劇的極端氣候，高山植物勢必得改變自身的代謝功能以適應氣候變遷。目前已有高山木本植物與草本植物轉錄體的研究。然而並不是只有植物本身在面對氣候變遷，與植物有共生關係的根部共生微生物群除了受到植物宿主本身的調控外，也會受到如溫度、濕度等氣候的影響。但對於極端環境與氣候變遷如何影響高山草本植物根部共生微生物群仍是未解之謎。台灣有四種當藥屬(Swertia)植物，生長的區域橫跨中低至高海拔。其中生長在低海拔地區的新店當藥(Swertia shintenensis)是二年生植物(biennials)，而生長在中高海拔地區的巒大當藥(Swertia macrosperma)、高山當藥(Swertia tozanensis)與阿里山當藥(Swertia arisanensis)皆為一年生植物(annuals)。本研究採集了當藥根際的土壤與當藥的根部作為實驗材料，並運用分子標籤與次世代定序解開當藥根際(rhizosphere)與根內(endosphere)共生微生物群的基因體資訊。研究發現根際與根內共生微生物群沒有隨著海拔變化的趨勢，但新店當藥的根際微生物群與其他三種當藥的根際微生物群有顯著差異。顯示了根際微生物組成可能有低海拔與中高海拔的差異，也可能與生命週期(life cycle)有所相關性。此外，新店當藥根內微生物的代謝功能也與其他當藥呈現顯著差異。根際土壤的酸鹼值可能會影響根際微生物的組成，其中對酸桿菌門的豐度影響最大。雖然巒大當藥與高山當藥是同域關係，但根際與根內微生物組成卻不是最相似的。顯示了台灣當藥屬植物根部微生物群與物種或環境複雜的交互作用。

Under the threats of global warming, alpine plants have to move to higher elevations and are thereby restricted by limited areas. Alpine plants must alter their metabolisms to face the climate change. Symbiotic bacteria in roots may help plants overcome such climate change. Nevertheless, the mutual influences between symbiotic root-associated bacteria and alpine plants under climate changes are still unknown. Four species of Swertia grow from low to high elevations in Taiwan, with S. shintenensis being biennial and growing in low elevations, and S. macrosperma, S. tozanensis, and S. arisanensis being annual and growing in higher elevations. In this study, rhizosphere soils and roots were collected, and 16S metagenomics was used to uncover the microbiome of rhizosphere and root endosphere. Although there was no significant trend of microbial change in the rhizosphere or endosphere along elevations, the microbiome in the rhizohsphere of S. shintenensis was significantly different from other Swertia species, showing that rhizosphere microbiome might be affected by altitudinal factors or life forms. In addition, microbial metabolisms in endosphere of S. shintenensis were different from those of others. On the other hand, soil pH values might affect the microbial compositions of the rhizosphere, as shown by the abundance of the Acidobacteria. Unexpectedly, sympatric S. macrosperma and S. tozanensis displayed different microbial compositions in rhizosphere and root endosphere.

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