Data_Sheet_6_Diversity in rhizospheric microbial communities in tea varieties at different locations and tapping potential beneficial microorganisms.docx

Soil microenvironments and plant varieties could largely affect rhizosphere microbial community structure and functions. However, their specific effects on the tea rhizosphere microbial community are yet not clear. Beneficial microorganisms are important groups of microbial communities that hold ecological functionalities by playing critical roles in plant disease resistance, and environmental stress tolerance. Longjing43 and Zhongcha108 are two widely planted tea varieties in China. Although Zhongcha108 shows higher disease resistance than Longjing43, the potential role of beneficial tea rhizosphere microbes in disease resistance is largely unknown. In this study, the structure and function of rhizosphere microbial communities of these two tea varieties were compared by using the Illumina MiSeq sequencing (16S rRNA gene and ITS) technologies. Rhizosphere soil was collected from four independent tea gardens distributed at two locations in Hangzhou and Shengzhou cities in eastern China, Longjing43 and Zhongcha108 are planted at both locations in separate gardens. Significant differences in soil physicochemical properties as demonstrated by ANOVA and PCA, and distinct rhizosphere microbial communities by multiple-biotech analyses (PCoA, LEfSe, Co-occurrence network analyses) between both locations and tea varieties (p < 0.01) were found. Functions of bacteria were annotated by the FAPROTAX database, and a higher abundance of Nitrososphaeraceae relating to soil ecological function was found in rhizosphere soil in Hangzhou. LDA effect size showed that the abundance of arbuscular mycorrhizal fungi (AMF) was higher in Zhongcha108 than that in Longjing43. Field experiments further confirmed that the colonization rate of AMF was higher in Zhongcha108. This finding testified that AMF could be the major beneficial tea rhizosphere microbes that potentially function in enhanced disease resistance. Overall, our results confirmed that locations affected the microbial community greater than that of tea varieties, and fungi might be more sensitive to the change in microenvironments. Furthermore, we found several beneficial microorganisms, which are of great significance in improving the ecological environment of tea gardens and the disease resistance of tea plants. These beneficial microbial communities may also help to further reveal the mechanism of disease resistance in tea and potentially be useful for mitigating climate change-associated challenges to tea gardens in the future.土壤微环境与植物品种可在很大程度上影响根际微生物群落的结构与功能。然而，二者对茶树根际微生物群落的具体影响仍未明确。有益微生物（beneficial microorganisms）是一类重要的微生物类群，可通过在植物抗病及环境胁迫耐受中发挥关键作用，赋予其生态功能。龙井43（Longjing43）与中茶108（Zhongcha108）是我国广泛种植的两大茶树品种。尽管中茶108的抗病性优于龙井43，但有益茶树根际微生物在抗病过程中的潜在作用仍未被充分探明。 本研究采用Illumina MiSeq测序（16S rRNA基因与ITS区间）技术，对比分析了这两个茶树品种的根际微生物群落结构与功能。研究共采集我国东部杭州与嵊州两座城市两处采样点的4个独立茶园根际土壤样本，两个茶树品种分别在两处采样点的独立茶园中种植。经方差分析（ANOVA）与主成分分析（PCA）证实，两处采样点的土壤理化性质存在显著差异；通过主坐标分析（PCoA）、线性判别分析效应大小（LEfSe）、共现网络分析等多生物技术分析手段发现，不同采样点与茶树品种的根际微生物群落结构亦存在显著差异（p < 0.01）。 本研究通过FAPROTAX数据库对细菌功能进行注释，发现杭州茶园根际土壤中与土壤生态功能相关的亚硝化古菌科（Nitrososphaeraceae）丰度更高。线性判别分析效应大小（LDA effect size）结果显示，中茶108的丛枝菌根真菌（arbuscular mycorrhizal fungi, AMF）丰度高于龙井43。田间试验进一步证实，中茶108的丛枝菌根真菌定殖率更高。该结果证实，丛枝菌根真菌可作为茶树根际的核心有益微生物，潜在参与增强茶树抗病性的过程。 综上，本研究结果证实，采样地点对微生物群落的影响程度大于茶树品种，且真菌对微环境变化的敏感性更高。此外，本研究筛选得到多株有益微生物，其对于改善茶园生态环境、提升茶树抗病性具有重要意义。这些有益微生物群落还有助于进一步解析茶树的抗病机制，未来或可用于缓解气候变化给茶园带来的各类挑战。