Zuzolo Daniela, Ranauda Maria Antonietta, Maisto Maria, Tartaglia Maria, Prigioniero Antonello, Falzarano Alessandra, Marotta Giuseppe, Sciarrillo Rosaria, Guarino Carmine
Department of Science and Technologies, University of Sannio, Benevento, Italy.
Department of Law, Economics, Management and Quantitative Methods (DEMM), University of Sannio, Benevento, Italy.
Front Plant Sci. 2023 Aug 14;14:1205451. doi: 10.3389/fpls.2023.1205451. eCollection 2023.
The rhizosphere effect occurring at the root-soil interface has increasingly been shown to play a key role in plant fitness and soil functionality, influencing plants resilience. Here, for the first time, we investigated whether the rootstock genotype on which L. cultivar Falanghina is grafted can influence the rhizosphere microbiome. Specifically, we evaluated to which extent the 5BB and 1103P rootstocks are able to shape microbial diversity of rhizosphere environment. Moreover, we explored the potential function of microbial community and its shift under plant genotype influence. We investigated seven vineyards subjected to the same pedo-climatic conditions, similar age, training system and management and collected twelve rhizosphere soil samples for metagenomic analyses and composite soil samples for physical-chemical properties. In this study, we used 16S rRNA gene-based metagenomic analysis to investigate the rhizosphere bacterial diversity and composition. Liner discriminant analysis effect size (LEFSe) was conducted for metagenomic biomarker discovery. The functional composition of sampled communities was determined using PICRUSt, which is based on marker gene sequencing profiles. Soil analyses involved the determination of texture, pH, Cation Exchange Capacity (CSC), Organic Carbon (OC), electrical conductivity (EC), calcium (Ca), magnesium (Mg), potassium (K) content, Phosphorous (P), nitrogen (N). The latter revealed that soil features were quite homogenous. The metagenomic data showed that the bacterial alpha-diversity (Observed OTUs) significantly increased in 1103P rhizosphere microbiota. Irrespective of cultivar, Pseudomonadota was the dominant phylum, followed by Actinomycetota > Bacteroidota > Thermoproteota. However, Actinomycetota was the major marker phyla differentiating the rhizosphere microbial communities associated with the different rootstock types. At the genus level, several taxa belonging to Actinomycetota and Alphaproteobacteria classes were enriched in 1103P genotype rhizosphere. Investigating the potential functional profile, we found that most key enzyme-encoding genes involved in N cycling were significantly more abundant in 5BB rootstock rhizosphere soil. However, we found that 1103P rhizosphere was enriched in genes involved in C cycle and Plant Growth Promotion (PGP) functionality. Our results suggest that the different rootstocks not only recruit specific bacterial communities, but also specific functional traits within the same environment.
根际土壤界面发生的根际效应越来越多地被证明在植物适应性和土壤功能中起关键作用，影响植物的恢复力。在此，我们首次研究了嫁接L.品种法兰吉娜（Falanghina）的砧木基因型是否会影响根际微生物群。具体而言，我们评估了5BB和1103P砧木在多大程度上能够塑造根际环境的微生物多样性。此外，我们探讨了微生物群落的潜在功能及其在植物基因型影响下的变化。我们调查了七个处于相同土壤气候条件、树龄相近、栽培系统和管理方式相似的葡萄园，并采集了十二个根际土壤样本用于宏基因组分析，以及复合土壤样本用于理化性质分析。在本研究中，我们使用基于16S rRNA基因的宏基因组分析来研究根际细菌多样性和组成。进行线性判别分析效应大小（LEFSe）以发现宏基因组生物标志物。使用基于标记基因测序图谱的PICRUSt确定采样群落的功能组成。土壤分析包括质地、pH值、阳离子交换容量（CSC）、有机碳（OC）、电导率（EC）、钙（Ca）、镁（Mg）、钾（K）含量、磷（P）、氮（N）的测定。后者表明土壤特征相当均匀。宏基因组数据显示，1103P根际微生物群中的细菌α多样性（观察到的OTU）显著增加。无论品种如何，假单胞菌门是优势菌门，其次是放线菌门>拟杆菌门>热变形菌门。然而，放线菌门是区分与不同砧木类型相关的根际微生物群落的主要标记菌门。在属水平上，属于放线菌门和α变形菌纲的几个分类群在1103P基因型根际中富集。在研究潜在功能谱时，我们发现参与氮循环的大多数关键酶编码基因在5BB砧木根际土壤中显著更为丰富。然而，我们发现1103P根际中参与碳循环和植物生长促进（PGP）功能的基因富集。我们的结果表明，不同的砧木不仅在同一环境中招募特定的细菌群落，还招募特定的功能性状。
