Microbial Functional Diversity in Vineyard Soils: Sulfur Metabolism and Links With Grapevine Plants and Wine Quality

Abstract

The quality of the vineyard soils has a direct impact on grapes and wine quality and represents a key component of the "Terroir concept." However, information on the impact of soil microbiota on grapevine plants and wine quality are generally lacking. In fact, over the last few years most of the attempts made to correlate soil microbial communities and wine quality were limited by overlooking both the functional traits of soil microbiota and the spatial variability of vineyards soils. In this work, we used a functional gene microarray approach (GeoChip) and soil enzymatic analyses to assess the soil microbial community functional potential related to the different wine quality. In order to minimize the soil variability, this work was conducted at a "within-vineyard" scale, comparing two similar soils (BRO11 and BRO12) previously identified with respect to pedological and hydrological properties within a single vineyard in Central Tuscany and that yielded highly contrasting wine quality upon cultivation of the same Sangiovese cultivar (BRO12 exhibited the higher quality). Our results showed an enrichment of Actinobacteria in BRO12, whereas Alfa-and Gamma-Proteobacteria were more abundant in BRO11, where an enrichment of bacteria involved in N fixation and denitrification occurred. Overall, the GeoChip output revealed a greater biological activity in BRO11 but a significant enrichment of sulfur-oxidation genes in BRO12 compared to BRO11 soil, where a higher level of arylsulfatase activity was also detected. Moreover, the low content of sulfates and available nitrogen found in BRO12 suggested that the reduced availability of sulfates for vine plants might limit the reduced glutathione (GSH) synthesis, which plays an important role in aroma protection in musts and wines. In conclusion, in addition to nitrogen availability, we propose that soil microbial sulfur metabolism may also play a key role in shaping plant physiology, grapes and wine quality. Overall, these results support the existence of a "microbial functional terroir" effect as a determining factor in vineyard-scale variation among wine grapes.

Soil management and plant protection strategies with reduced use of copper: productive and environmental aspects in a Sangiovese vineyard

“…However, GG management increased the Proteobacteria/Acidobacteria ratio in all plots (Tab.6), independently to the soil management, suggesting an improvement of soil nutritional status. This result confirms the key role of Proteobacteria in soil nutrient cycling in Sangiovese vineyards from Tuscany, as recently reported [35]. Fifteen different taxa of microarthropods were identified in the soil.…”

“…The reduced copper applications in GG management gave in some years a higher downy mildew severity on leaves and clusters but no significant yield loss. The study showed no significant difference between a vineyard conducted with permanent grass or green manure, as found by other authors [35][36].…”

Soil health, soil genetic horizons and biodiversity#

“…In this complex scenario, both composition and functions of soil biota are also significantly affected by soil features and their spatiotemporal heterogeneity, which makes it difficult to link specific soil microbial taxa to many soil processes (Fierer, 2017; Gottschall et al., 2021; Kuzyakov & Blagodatskaya, 2015; Mocali et al., 2020; Nemergut et al., 2013). As discussed later, spatial variability in distributions of soil microorganisms has been largely explored in the last decade (Delgado‐Baquerizo et al., 2018; Thompson et al., 2017).…”

Current Methods, Common Practices, and Perspectives in Tracking and Monitoring Bioinoculants in Soil

“…An impetus toward this goal could derive from the field of microfluidics applications and tools like the “lab-on-chip” ( Aleklett et al, 2018 ) could have the potential to address some of the major challenges of tracking and monitoring of bioinoculants. The “lab-on-chip” (microarray) technology opens the avenue for the parallel, high-throughput multiple identification of target microorganisms and genes in environmental samples ( Wilson et al, 2002 ; Chandler et al, 2010 ; Schreiner et al, 2010 ; Mocali et al, 2020 ). Data obtained with amplification microarrays correlated well with conventional small subunit rRNA qPCR results ( Chandler et al, 2010 ).…”