Plant tissue metagenomic sequencing

Bacterial canker, caused by Pseudomonas syringae pv. actinidiae (Psa), is a highly destructive disease affecting kiwifruit (Actinidia spp.), with its severity modulated by environmental conditions and host genetic background. Nevertheless, the interactions between bacterial canker and the plant microbiome remain poorly characterized. This study comparatively analyzed the rhizosphere and endophytic bacterial communities of two kiwifruit varieties, Actinidia chinensis 'Hongyang' (susceptible) and A. chinensis 'Hort16A' (resistant), in both healthy and diseased plants, using Illumina MiSeq sequencing. Additionally, fluorescence in situ hybridization (FISH) was employed to visualize the spatial distribution of key antagonistic bacteria within plant branches. Significant differences in bacterial community composition were observed between varieties and between health statuses within each variety. Dominant genera such as Pseudomonas, unclassified_f_Enterobacteriaceae, unclassified_o_Enterobacterales, Enterobacter, and Erwinia, exhibited distinct distribution patterns in 'Hongyang' and 'Hort16A'. Notably, healthy 'Hort16A' plants harbored a higher abundance of antagonistic bacteria, including Lactobacillus and Bifidobacterium, whereas 'Hongyang' and diseased plants showed increased proportions of Pseudomonas and Erwinia. These results indicate that bacterial canker infection restructures the endophytic bacterial community and suggest that specific beneficial taxa may underlie host resistance mechanisms. These insights provide a foundation for developing microbiome-based management strategies against bacterial canker.

由丁香假单胞菌猕猴桃致病变种（Pseudomonas syringae pv. actinidiae, Psa）引发的细菌性溃疡病是危害猕猴桃属（Actinidia spp.）植物的毁灭性病害，其发病严重程度受环境条件与宿主遗传背景共同调控。然而，目前对于细菌性溃疡病与植物微生物组之间的互作关系仍缺乏充分解析。本研究采用Illumina MiSeq测序技术，对健康与染病状态下的两个猕猴桃品种——中华猕猴桃（Actinidia chinensis）‘红阳’（感病品种）与中华猕猴桃‘Hort16A’（抗病品种）的根际与内生细菌群落进行了比较分析。此外，本研究还采用荧光原位杂交（fluorescence in situ hybridization, FISH）技术，可视化观测了植物枝条内关键拮抗菌的空间分布特征。研究发现，不同猕猴桃品种间以及同一品种内健康与染病植株的细菌群落组成均存在显著差异。假单胞菌属（Pseudomonas）、未分类肠杆菌科（unclassified_f_Enterobacteriaceae）、未分类肠杆菌目（unclassified_o_Enterobacterales）、肠杆菌属（Enterobacter）以及欧文氏菌属（Erwinia）等优势菌属在‘红阳’与‘Hort16A’中呈现出截然不同的分布模式。值得注意的是，健康状态的‘Hort16A’植株中，乳杆菌属（Lactobacillus）与双歧杆菌属（Bifidobacterium）等拮抗菌的丰度更高；而‘红阳’以及染病植株中，假单胞菌属与欧文氏菌属的相对占比则显著升高。上述研究结果表明，细菌性溃疡病侵染会重塑植株内生细菌群落，同时提示特定有益类群可能是宿主抗病机制的重要基础。本研究结果为开发基于微生物组的细菌性溃疡病防控策略提供了理论依据。