南京農業大學資環學院土壤微生物與有機肥團隊關於根際微生物群落組裝與土傳病害預測的最新研究成果“Small changes in rhizosphere microbiome composition predict disease outcomes earlier than pathogen density variations”在The ISME journal在線發表，成果證明了植物發育早期能夠快速分異出不同的根際微生物組，繼而決定後期土傳病害的發生，且根際微生物組比病原菌丰度更早地預測了病害的發生。

博士畢業生谷益安為文章第一作者，韋中教授為通訊作者，沈其榮院士、徐陽春教授、Alexandre Jousset教授、北達卡他州立大學Samiran Banerjee教授、賓夕法尼亞州立大學Francisco Dini-Andreote博士等參與了該項研究，該研究得到國家重點研發計劃青年科學家項目和國家自然科學基金等項目的資助。

doi：10.1038/s41396-022-01290-z

Even in homogeneous conditions, plants facing a soilborne pathogen tend to show a binary outcome with individuals either remaining fully healthy or developing severe to lethal disease symptoms. As the rhizosphere microbiome is a major determinant of plant health, we postulated that such a binary outcome may result from an early divergence in the rhizosphere microbiome assembly that may further cascade into varying disease suppression abilities. We tested this hypothesis by setting up a longitudinal study of tomato plants growing in a natural but homogenized soil infested with the soilborne bacterial pathogen Ralstonia solanacearum. Starting from an originally identical species pool, individual rhizosphere microbiome compositions rapidly diverged into multiple configurations during the plant vegetative growth. This variation in community composition was strongly associated with later disease development during the later fruiting state. Most interestingly, these patterns also significantly predicted disease outcomes 2 weeks before any difference in pathogen density became apparent between the healthy and diseased groups. In this system, a total of 135 bacterial OTUs were associated with persistent healthy plants. Five of these enriched OTUs (Lysinibacillus, Pseudarthrobacter, Bordetella, Bacillus, and Chryseobacterium) were isolated and shown to reduce disease severity by 30.4–100% when co-introduced with the pathogen. Overall, our results demonstrated that an initially homogenized soil can rapidly diverge into rhizosphere microbiomes varying in their ability to promote plant protection. This suggests that early life interventions may have significant effects on later microbiome states, and highlights an exciting opportunity for microbiome diagnostics and plant disease prevention.

植物根際微生物群落組裝分異與土傳病害結果關係探究

（A-C）研究假說；（D-E）試驗設計；（F）病原菌丰度時間動態變化；（G）根際細菌群落動態變化

大多農田土壤都不同程度地被植物病原菌侵染。即使在均質條件下，土傳植物病原體侵染仍普遍存在二元結果—健康和發病。然而，該現象的潛在機制仍然未被充分探索。本研究採用均質化的自然土壤實施溫室試驗並在個體水平上對整個生長季的番茄植株進行了跟蹤監測，結果發現宿主根際微生物群落在營養生長期即產生顯著分異，根際微生物群落分異繼而決定後期土傳青枯病結果，且根際微生物組對病害的預測早於病原菌丰度兩週。進一步從首次出現分異的根際細菌群落中找到協助植物抗病的類群，並通過純培養手段獲得了其中部分菌株，上述菌株可使青枯病發病降低30.4%~100%。病原菌丰度被廣泛用作病害發展的預測指標。然而，當檢測到高病原菌密度時，病情控制通常為時已晚。上述結果證明了宿主早期根際微生物群落組裝對於防禦病原菌入侵具有重大影響，為基於土壤微生物組的土傳病害診斷和防控提供了借鑑。

校對和審核：張陽 王農