Table 1_A conserved bacterial signature characterizes plant microbiome responses to drought.xlsx

IntroductionPlant-associated microbes contribute to host resilience under stress, yet the extent to which microbial responses to drought generalize across hosts and environments remains unclear.
MethodsHere, we performed a meta-analysis of 13 studies including more than 3,000 root and bulk soil samples from 52 plant hosts to identify bacterial taxa consistently affected by drought and link them to inoculation outcomes. Using a standardized processing workflow and differential abundance analysis, we derived a “drought signature” of taxa differentially abundant under water limitation across the endosphere, rhizosphere, and bulk soil.
ResultsThe signature is dominated by Gram-positive Actinobacteria enriched under drought, including Kribella, and by Gram-negative taxa depleted under drought, such as Ramilbacter. Comparison with four independent inoculation experiments revealed limited overlap between drought and inoculation responses, with only Nitrospira depleted in both contexts.
DiscussionStudies reporting improved plant performance under inoculation also exhibited stronger and more extensive microbial shifts, suggesting that the magnitude of community restructuring may be characteristic of successful inoculation outcomes. This work provides the fi rst genus-level meta-analysis of microbial responses under drought and inoculation, across hosts and experimental conditions, and delivers a unifi ed root and soil microbiome dataset.

**引言** 植物相关微生物可提升宿主在胁迫下的抗逆能力，但微生物对干旱的响应在多大程度上能在不同宿主与环境中通用，目前仍不明确。
**方法** 本研究对13项已发表研究开展荟萃分析，共纳入来自52种植物宿主的3000余份根系及原状土壤（bulk soil）样本，旨在筛选出受干旱持续影响的细菌类群（taxa），并将其与微生物接种（inoculation）效果建立关联。本研究采用标准化处理流程与差异丰度分析（differential abundance analysis）方法，在根内圈（endosphere）、根际圈（rhizosphere）及原状土壤中，筛选出水分限制条件下丰度发生显著变化的类群，以此构建“干旱特征谱（drought signature）”。
**结果** 该干旱特征谱以干旱条件下富集的革兰氏阳性放线菌门（Actinobacteria）类群为主，包括Kribella属；同时包含干旱条件下丰度耗竭的革兰氏阴性类群，例如Ramilbacter属。通过与4项独立接种实验的结果进行比对发现，干旱响应与接种响应之间的重叠度极低，仅Nitrospira属在两种情境下均呈现丰度耗竭的特征。
**讨论** 那些报道了接种可提升植物生长表现的研究，同时也观测到了更强且更广泛的微生物群落变化，这表明群落重构的强度或许是接种成功的标志性特征。本研究首次在跨宿主与实验条件的范围内，针对干旱与接种情境下的微生物响应开展了属级水平的荟萃分析，并构建了统一的根系与土壤微生物组数据集。