Grapevine decline is associated with difference in soil microbial composition and activity

Abstract

Grapevine decline is a top concern in viticulture worldwide and is often associated with many biotic and abiotic factors. Grape trunk diseases and viruses are some of the most frequently identified causes of vine dieback. However, a decline is sometimes observed when no mineral deficiency or excess, or pathogenic causes can be identified. Soil enzymatic and microbial activities are relevant bio-indicators since they are known to influence vine health. Grapevine associated microbiota, linked to vine fitness, is known to be influenced by soil microbiota coming from the microbial pool inhabiting the vineyard. This work describes the microbial diversity and activity of four different vineyard plots of the Bordeaux region, selected due to the presence of localised declining areas unexplained yet by disease symptoms. Soils were sampled in declining areas and areas within the same plot showing no decline symptoms, during autumn and spring periods. Significant differences in enzymatic activities, microbial biomass and activity were found among soils even if those soils presented quite similar physicochemical characteristics that could not explain these observed declines. The results of enzymatic assays distinguished patterns in autumn and spring periods with an overall greater enzymatic activity in soils from non-declining areas. This work suggests that soils displaying decline symptoms present a dysbiosis in functionality and diversity which is linked to vine health.

Soil composition and rootstock genotype drive the root associated microbial communities in young grapevines

“…Two soils were sampled in a vineyard from one Bordeaux region terroir (France), located in Graves’s appellation, described in Darriaut et al (2021) as vineyard number 2. The physicochemical parameters of the soils, the different rootstock/scion combinations, and the vigour of the plants are described in Darriaut et al (2021) .…”

“…Two soils were sampled in a vineyard from one Bordeaux region terroir (France), located in Graves’s appellation, described in Darriaut et al (2021) as vineyard number 2. The physicochemical parameters of the soils, the different rootstock/scion combinations, and the vigour of the plants are described in Darriaut et al (2021) . Briefly, the vineyard has been planted in 2010, and is located on sandy soil under a sub-humid temperate climate with cool nights and a low risk of extreme temperatures, subtyped as Cfb in Köppen climate classification.…”

“…A survey of soil microbiome was previously conducted in a multisite study within vineyards affected by localized and unexplained decline ( Darriaut et al, 2021 ). Despite relatively similar physicochemical features, lower enzymatic activities and different microbial profiles were found in soils supporting symptomatic vines (namely S soils) compared to soils presenting well-growing and asymptomatic vines (AS soils).…”

“…Despite relatively similar physicochemical features, lower enzymatic activities and different microbial profiles were found in soils supporting symptomatic vines (namely S soils) compared to soils presenting well-growing and asymptomatic vines (AS soils). The aim of the present work was to study how young, grafted plants from the nursery respond to the different microbiome compositions of soils from symptomatic (S) and asymptomatic (AS) areas of a vineyard affected by unexplained decline described in Darriaut et al (2021) . To evaluate the effect of the rootstock, grafted plants constituted on Vitis vinifera L. Cabernet Sauvignon grafted on either 1103P or RGM rootstocks were grown in pots filled with these soils in a 4-month greenhouse experiment.…”

The microbiota of the grapevine holobiont: A key component of plant health

“…Differences in microbial communities between symptomatic and asymptomatic plants, when they exist, seem to be localized at the level of the grapevine rhizosphere, not in the wood or the leaves (see Fig. 3 ; [146] , [165] , [166] . The abundance of the genera Phaeoacremonium and Phaeomoniella has been found higher in soils associated with symptomatic grapevines compared to asymptomatic ones [55] .…”