Genomic characterization of terpene biosynthetic genes in seven Vitis vinifera L. varieties 

In grafted plants, such as grapevine, increasing the diversity of rootstocks available to growers is an ideal strategy to get adaptation to climate change. The rootstocks used for grapevine are hybrids of various American Vitis, including V. berlandieri. The rootstocks currently used in vineyards are derived from breeding programs involving very small numbers of parental individuals.

Botrytis bunch rot occurrence is the most important limitation for the wine industry in humid environments. The effect of grapevine vegetative growth on bunch rot expression results from direct effects (cluster architecture, nitrogen status among others) and indirect ones (via microclimate). Previous studies of our group showed strong differences in bunch rot incidence between floor management treatments: cover crop (CC) vs weed-free strips under the trellis with herbicide (H). We observed that in some circumstances this reduction in bunch rot incidence occurred without major vine growth differences among treatments. The aim of the present study was to test the general hypothesis that other factors unrelated to grapevine vegetative expression could be more relevant to grapevine susceptibility to bunch rot.

Polyphenols are very important compounds of red wines, serving as essential bioactive components and playing an important role in sensory properties. The determination of individual phenolic compounds in red wine is commonly performed by HPLC analysis, while the total polyphenols are quantified by spectrophotometric methods, usually by the method of absorbance at 280 nm (index of ribéreau-gayon) or the method of index of folin-ciocalteu. In this work, we pioneeringly proposed a new and fast method for simultaneous determination of individual and total polyphenols in red wines by direct-injection HPLC without sample preparation.

Recently, foliar treatments with mineral-based compounds have shown positive effects on grapevine production by protecting grape from thermal excesses and reducing the decoupling between technological and phenolic maturity caused by climate change. Unraveling the effect of mineral particle applications on grape-associated microbes is pivotal for successful wine processing, due to the influence of the microbiota on wine composition and stability. To our knowledge, this is the first work that comprehensively studied the effects of kaolin and chabasite-rich zeolitites treatments on grape-related microorganisms (by real-time PCR quantification of total fungi, Hanseniospora uvarum, Metschnikowia pulcherrima, plant-associated bacteria and lactic acid bacteria), the expression of genes related to the flavonoid biosynthesis (PAL1, CHS1, F3H2, DFR, LDOX, UFGT, MYBA1, GST4, FLS4 genes) and the berry composition (°Brix, pH, acidity and anthocyanin concentrations) in cv. Sangiovese during ripening in two growing seasons (2019 and 2020).

Conventional molecular analyses provide bulk genomic/transcriptomic data that are unable to reveal the cellular heterogeneity and to precisely define how gene networks orchestrate organ development. We will profile gene expression and identify open chromatin regions at the individual cells level, allowing to define cell-type specific regulatory elements, developmental trajectories and transcriptional networks orchestrating organ development and function. We will perform scRNA-seq and snATAC-seq on leaf/berry protoplasts and nuclei and combine them with the leaf/berry bulk tissues obtained results, where the analysis of transcripts, chromatin accessibility, histone modification and transcription factor binding sites showed that a large fraction of phenotypic variation appears to be determined by regulatory rather than coding variation and that many variants have an organ-specific effect.