I care more about Drosera than the origin of all the species in the world ~ Charles Darwin

食蟲植物與微生物共生系統:揭開捕食葉背後的微生物夥伴與三方互動機制. Microbial Partnerships in Carnivorous Plants: Uncovering the Tripartite Interactions Behind Digestive Leaves

我們的目標

本研究計畫旨在探索食蟲植物與其共生微生物之間複雜而動態的互動關係。我們聚焦於植物、細菌與真菌如何共同參與昆蟲的分解與營養吸收，並試圖釐清這種「多物種合作」的機制是否為植物捕食策略成功的關鍵。我們希望透過基因體學、轉錄體分析與微生物組學，建立食蟲植物作為研究植物–微生物–獵物三方互動的模型系統，從中揭示共演化與生理整合的新樣貌。

This research project aims to explore the complex and dynamic interactions between carnivorous plants and their microbial partners. We focus on how plants, bacteria, and fungi collaborate in prey digestion and nutrient assimilation, and whether such multi-species cooperation is key to the success of botanical carnivory. By integrating genomics, transcriptomics, and microbiome analyses, we seek to establish carnivorous plants as model systems for studying three-way interactions among hosts, microbes, and prey—offering new insights into co-evolution and physiological integration.

在自然界中，食蟲植物發展出獨特的葉片構造與消化酵素來捕食昆蟲，作為應對營養匱乏環境的策略。然而，近期我們的研究揭示，這樣的捕食過程並非植物單方面的行為，而是涉及植物、細菌與真菌三方合作的微生物共生系統（holobiont）。我們以原生於台灣的毛氈苔（Drosera spatulata）為模式，深入解析其分泌的消化黏液所承載的微生物社群。研究發現，黏液中的酸性環境長期穩定地富集一種嗜酸性真菌——Acrodontium crateriforme，此菌不僅在多種毛氈苔中廣泛存在，且其基因體顯示出適應共生生活的演化特徵，如植物細胞壁分解酶的缺失與次級代謝基因群的獨特擴張。

In nutrient-poor environments, carnivorous plants have evolved specialised leaf structures and digestive enzymes to trap and digest insect prey. However, our recent findings suggest that prey digestion is not solely a plant-driven process. Instead, it involves a microbial holobiont—a dynamic community in which the plant, bacteria, and fungi work in concert. Using the Taiwanese native sundew Drosera spatulata as a model, we characterised the microbial communities inhabiting its sticky digestive mucilage. We found that this acidic microhabitat consistently supports the growth of a dominant acidophilic fungus, Acrodontium crateriforme, which is not only widespread across Drosera species but also shows genomic signatures of symbiotic adaptation—such as the loss of plant cell wall-degrading enzymes and the expansion of unique secondary metabolite biosynthetic gene clusters.

在與植物共處及進行昆蟲消化的階段中，A. crateriforme 表現出強烈的蛋白酶活性，與毛氈苔本身的消化酵素（如cysteine與aspartic peptidases）發生轉錄協同作用，顯著提升獵物的分解效率。這樣的合作也促進植物對氮的吸收，並加快捕蟲葉回復原狀的速度，進一步提高捕食頻率與營養獲取效益​ 。更重要的是，真菌的存在不只是「幫忙分解」，它還能提前誘發植物的茉莉酸（JA）訊號通路，使植物在尚未捕捉到獵物前就處於「消化預備狀態」。這類「預備啟動」的現象與我們過去在其他植物防禦反應中的觀察一致，顯示植物與共生微生物間具有更深層的訊號整合能力。

During prey digestion, A. crateriforme exhibits high protease activity and shows synergistic transcriptomic responses with the host plant’s own digestive enzymes, such as cysteine and aspartic peptidases. This cooperation significantly enhances prey decomposition, accelerates leaf recovery, and improves nitrogen uptake by the plant. Remarkably, the fungus also primes the host’s jasmonate signalling pathway even before prey arrives, placing the plant in a heightened “ready-to-digest” state—analogous to immune priming observed in other plant–microbe interactions.

We also observed that bacterial communities in the mucilage vary in composition and abundance depending on host species, environment, and pH, and may interact with fungal partners in either complementary or competitive ways. This suggests the presence of a dynamically regulated tripartite system—plant, bacteria, and fungus—co-shaping the efficiency of prey digestion and nutrient acquisition.

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我們亦觀察到細菌社群在黏液中的角色可能不容忽視：它們的多樣性與組成受到植物種類、環境與黏液酸鹼值所影響，與真菌的優勢存在明顯互補或競爭的趨勢。這暗示著毛氈苔黏液中可能存在一個動態調控的三方系統——植物–細菌–真菌—共同影響獵物分解與營養獲取的效率。我們未來將進一步探討其他食蟲植物如瓶子草、捕蟲堇等是否也具有類似的微生物參與機制，並釐清不同微生物間如何在捕食過程中分工合作。

Moving forward, we aim to investigate whether similar microbial partnerships exist in other carnivorous plants and how different microbial players divide labour and integrate signals during the digestion process.

Selected publication

1. An acidophilic fungus is integral to prey digestion in a carnivorous plant Nature Microbiology
   PF Sun, MR Lu, YC Liu, BJP Shaw, CP Lin, HW Chen, YF Lin, DZ Hoh, HM Ke, IF Wang, MEJ Lu, EB Young, J Millett, R Kirschner, YCJ Lin, YL Chen and IJ Tsai.

Selected news

1. Share the meat Research Highlight in nature plants.
2. Fungal discovery changes the way we understand Charles Darwin’s most beloved plant – the sundew - the microbiologist