(1)病原体要想成功侵染植物,不仅要克服植物自身的免疫系统,还要突破微生物组构成的“微生物屏障”。但目前对抗微生物效应蛋白如何在不同生态环境中帮助病原体定殖的理解仍然有限。
(2)微生物群落驱动因素不同 根际细菌和真菌群落主要受土壤类型影响;叶际微生物群落主要受植物种类影响
(3)抗微生物效应蛋白 Ave1 对微生物组的影响及其对病原体毒力的贡献,取决于土壤来源的微生物群落,即具有环境依赖性。
揭示了病原体效应蛋白的功能不是一成不变的,而是在不同生态环境中表现出复杂性
Background
(1)Throughout their life cycle, plants associate with diverse and complex microbial communities collectively known as their microbiota. 在整个生命周期中,植物与各种复杂的微生物群落结合在一起,统称为微生物群。
(2)These microbiota contribute to plant performance and health by enhancing nutrient acquisition, modulating immunity, and providing a microbial barrier against pathogens 这些微生物群通过增强营养获取、调节免疫和提供对抗病原体的微生物屏障来促进植物生长和健康 .
(3)To successfully colonize their hosts, pathogens must overcome not only plant immune defenses but also this microbial barrier 为了成功地在宿主体内定居,病原体不仅要克服植物的免疫防御,还要克服微生物的屏障 .
(4)For example, the soil-borne fungal pathogen Verticillium dahliae secretes the antimicrobial effector Ave1 to suppress antagonistic microbes and facilitate infection. Although many plant pathogens, including V. dahliae, inhabit both plant-associated and soil environments, how antimicrobial effectors contribute to pathogen establishment across these diverse ecological contexts remains poorly understood. 例如,土传真菌病原体大丽轮枝菌分泌抗微生物效应子Ave1来抑制拮抗微生物并促进感染。尽管许多植物病原体,包括大丽花病菌,都存在于植物相关环境和土壤环境中,但是抗微生物效应物是如何在这些不同的生态环境中促进病原体的建立的仍然知之甚少。
(5)To explore this question, we assembled a collection of natural soils differing in physicochemical properties and microbiota composition. 为了探索这个问题,我们收集了一批物理化学性质和微生物组成不同的自然土壤。
(6)Using three host plant species—barley, tomato, and cotton—we found that root-associated bacterial and fungal communities were primarily shaped by type of soil, whereas phyllosphere microbiota were mainly determined by plant species identity. On tomato, we further observed that the effector Ave1 differentially contributed to V. dahliae virulence depending on the soil of origin. While Ave1 consistently altered tomato-associated microbiota across all soils tested, the specific microbial taxa affected varied between soils. 在番茄上,我们进一步观察到效应器Ave1根据来源的土壤而不同地促成了大丽轮枝菌的毒性。虽然Ave1在所有测试的土壤中一致地改变了番茄相关的微生物群,但受影响的具体微生物类群在土壤之间有所不同。
(7)Our findings demonstrate that the impact of the antimicrobial effector Ave1 on microbiota composition and pathogen virulence is context-dependent, influenced by the specific soil-derived microbial community that assembles on the host. This work highlights the ecological complexity of effector functions and suggests that pathogen success in natural environments depends on dynamic interactions with both the plant host and its microbiota. 我们的研究结果表明,抗微生物效应子Ave1对微生物群组成和病原体毒力的影响是上下文相关的,受到在宿主上聚集的特定土壤来源的微生物群落的影响。这项工作强调了效应器功能的生态复杂性,并表明病原体在自然环境中的成功取决于与植物宿主及其微生物群的动态相互作用。
(8)Result
(9)Composing a collection of diverse natural soil samples构建多样化的自然土壤样本集合
Figure 1. Establishment of a natural soil collection. a) Soil collection sites in the Netherlands. Themap is colored according to major types of soil in the Netherlands. Sampling locations are indicatedby red squares. b) Pictures of each soil from the soil sample collection
图2. 自然土壤样品的理化性质与微生物组分析
a) pH值热图 b) 土壤碳含量箱线图 c) 土壤氮含量箱线图 d) ICP-MS测量元素相对丰度条形图 e) 元素谱主成分分析(PCA) f) 细菌本体土壤微生物组的加权UniFrac距离主坐标分析(PCoA) g) 真菌本体土壤微生物组的加权UniFrac距离主坐标分析(PCoA)
(10) Drivers of bacterial community assembly in roots and phyllosphere microbiota根系与叶际微生物组中细菌群落组装的驱动因素
图3. 大麦、棉花和番茄植株在不同自然土壤上生长时,其根系和叶际相关微生物组的细菌组成
a) 细菌根系微生物组在门水平上的相对丰度百分比
b) 细菌叶际微生物组在门水平上的相对丰度百分比
c) 根系微生物组的Shannon指数
d) 叶际微生物组的Shannon指数
e) 基于加权UniFrac距离的根系微生物组主坐标分析(PCoA)
f) 基于加权UniFrac距离的叶际微生物组主坐标分析(PCoA)
g) 基于加权UniFrac距离的根系微生物组主坐标分析(PCoA)
h) 基于加权UniFrac距离的叶际微生物组主坐标分析(PCoA)
(11) Drivers of fungal community assembly in root-associated and phyllosphere microbiota 根系相关与叶际微生物组中真菌群落组装的驱动因素
图4. 大麦、棉花和番茄植株在不同自然土壤上生长时,其根系和叶际相关微生物组的真菌组成
(12) Differential contribution of antimicrobial effectors to fungal virulence across types of soi 抗微生物效应蛋白在不同土壤类型中对真菌毒力的差异性贡献
图5. 抗微生物效应蛋白Ave1对大丽轮枝菌(Verticillium dahliae)毒力的贡献因土壤类型而异
a) 不同自然土壤上生长的番茄植株在接种后14天(14 dpi)的冠层面积(cm²)
处理组包括:模拟接种(mock)、野生型大丽轮枝菌(JR2)、以及Ave1缺失突变体(ΔAve1)。
b) 基于UniFrac距离的主坐标分析(PCoA)
展示在不同土壤上生长的番茄植株,在接种野生型大丽轮枝菌(JR2)或Ave1缺失突变体(ΔAve1)后14天(14 dpi),其根系微生物组的β多样性。数据点按处理组着色。
土传真菌病原体大丽轮枝菌分泌抗微生物效应子Ave1来抑制拮抗微生物并促进感染。尽管许多植物病原体,包括大丽花病菌,都存在于植物相关环境和土壤环境中,但是抗微生物效应物是如何在这些不同的生态环境中促进病原体的建立的仍然知之甚少