Mining microbiome data to identify antagonists of grapevine downy mildew (Plasmopara viticola)

Vitis vinifera L. derivatives are susceptible to contamination by biological agents (e.g., bacteria, viruses, fungi), and chemical agents (e.g., heavy metals, persistent organic pollutants).

Climate change effects on grapevine phenology and grape primary and secondary metabolites are well described in recent literature. Increasing frequency and intensity of heat waves may be responsible for important yield losses in the future. However, the impact of this event is not so well described in literature. The present study highlights the importance of grape variety tolerance as a mitigation tool to climate change.

In response to changes in their environment, grapevines regulate transpiration using various physiological mechanisms that alter conductance of water through the soil-plant-atmosphere continuum. Expressed as bulk stomatal conductance at the canopy scale, it varies diurnally in response to changes in vapor pressure deficit and net radiation, and over the season to changes in soil water deficits and hydraulic conductivity of both soil and plant. It is necessary to characterize the response of conductance to these variables to better model how vine transpiration also responds to these variables. Furthermore, to be relevant for vineyard-scale modeling, conductance is best characterized using data collected in a vineyard setting. Applying a crop canopy energy flux model developed by Shuttleworth and Wallace, bulk stomatal conductance was estimated using measurements of individual vine sap flow, temperature and humidity within the vine canopy, and estimates of net radiation absorbed by the vine canopy. These measurements were taken on several vines in a non-irrigated vineyard in Bordeaux France, using equipment that did not interfere with ongoing vineyard operations. An inverted Penman-Monteith equation was then used to calculate bulk stomatal conductance on 15-minute intervals from July to mid-September 2020. Time-series plots show significant diurnal variation and seasonal decreases in conductance, with overall values similar to those in the literature. Global sensitivity analysis using non-parametric regression found transpiration flux and vapor pressure deficit to be the most important input variables to the calculation of bulk stomatal conductance, with absorbed net radiation and bulk boundary layer conductance being much less important. Conversely, bulk stomatal conductance was one of the most important inputs when calculating vine transpiration, further emphasizing the need for characterizing its response to environmental changes for use in vineyard water use modeling.

Context and purpose of the study. Epidermal Patterning Factors are a family of small peptides that are highly conserved in the plant kingdom and are involved in several physiological and developmental processes.

Aim: Grapevine has traditionally been widely cultivated in drylands. However, in recent decades, a significant part of the viticulture all over the word and specifically in Mediterranean basin, is being irrigated. In recent years, due to climate change, among other reasons, the available natural water resources have been reduced substantially compromising the sustainability of viticulture, especially in the most arid areas