Plants interact with a myriad of microbial cells in the rhizosphere, an environment that is considered to be important for plant development. However, the differential structuring of rhizosphere microbial communities due to plant cultivation under differential agricultural practices remains to be described for most plant species. Here we describe the rhizosphere microbiome of grapevine cultivated under conventional and organic practices, using a combination of cultivation-independent approaches. The quantification of bacterial 16S rRNA and nifH genes, by quantitative PCR (qPCR), revealed similar amounts of these genes in the rhizosphere in both vineyards. PCR-DGGE was used to detect differences in the structure of bacterial communities, including both the complete whole communities and specific fractions, such as Alphaproteobacteria, Betaproteobacteria, Actinobacteria, and those harboring the nitrogen-fixing related gene nifH. When analyzed by a multivariate approach (redundancy analysis), the shifts observed in the bacterial communities were poorly explained by variations in the physical and chemical characteristics of the rhizosphere. These approaches were complemented by high-throughput sequencing (67,830 sequences) based on the V6 region of the 16S rRNA gene, identifying the major bacterial groups present in the rhizosphere of grapevines: Proteobacteria, Actinobacteria, Firmicutes, Bacteriodetes, Acidobacteria, Cloroflexi, Verrucomicrobia and Planctomycetes, which occur in distinct proportions in the rhizosphere from each vineyard. The differences might be related to the selection of plant metabolism upon distinct reservoirs of microbial cells found in each vineyard. The results fill a gap in the knowledge of the rhizosphere of grapevines and also show distinctions in these bacterial communities due to agricultural practices.
Land-use effects on microbial communities may have profound impacts on agricultural productivity and ecosystem sustainability because they are critical to soil quality and health. Within this context, soil microbiological properties such as microorganism abundance, total microbial biomass, and enzymatic activities have been used as soil quality indicators. However, these properties are very sensitive to changes triggered by agronomic management. The aim of this work was to evaluate the effect of agricultural practices in the vineyards from the Central Monte Desert, San Juan, Argentina including the effects on soil microbial biomass using soils from the open shrubland as a reference. The microbial biomass carbon was significantly greater in soils from the open shrubland than in the vineyards during April and November. The abundance of cultivable soil microorganisms (bacteria and filamentous fungi) in soil samples from vineyards and open shrubland was statistically similar. Vineyard soils showed increased enzymatic activities (both in rows and between rows) in both seasons. We used multivariate analysis of all data measured here to propose a data set of variables (amylase, cellulase, and xylanase activities, bacterial abundance, microbial biomass and water content, pH and electric conductivity) for use in future studies of soil quality in the Central Monte Desert.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
hi@scite.ai
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.