Population-wide diversity study in Lachancea thermotolerans highlights superior starters for winemaking

The oenological potential of grapes at harvest depends on a combination of the major components of Terroir: the climate, the soil, the plant material, the training system and the crop management.

Heatwaves, defined as three or more consecutive days above average historical maximum temperatures, are having a significant impact on agricultural crop yields and quality, especially in arid or semi-arid regions with reduced water availability during the growing season.

Grapes (Vitis vinifera L.) are a fruit crop of high economic significance globally. Each grapevine cultivar is characterized by its distinctive grape aroma, affecting the wine quality. In several cultivars, the aroma is shaped by terpenoid (mono- and sesqui-terpenoids). Their profile is controlled by terpene synthases (TPS), which are part of a largely expanded gene family. How the variation in TPS copy number and sequence among cultivars determines terpenoid profiles of grapes remains largely unexplored. We annotated TPS in the haplotypes of seven genomes (Riesling, Albariño, Fiano, Gewürztraminer, Pinot Noir, Cabernet Sauvignon, and Viognier) using BLAST, GMAP, PFAM, and phylogenetic analyses. Further, TPS expression patterns and terpenoid accumulation during berry development and ripening were characterized using RNA-Seq and SPME/GC-MS platforms, respectively. Variation in TPS copy number exists among cultivars. Specifically, the TPS counts span a range of 251 to 150 for Riesling and Fiano, respectively, when considering combined haplotypes within each cultivar. Total terpenoid accumulation patterns throughout development were consistent among the five aromatic cultivars, marked by high concentrations in flowers, followed by a decline and subsequent rise during berry development and ripening, respectively. Conversely, non-aromatic cultivars exhibited no substantial increase in terpenoid concentration during ripening. Transcriptome and network analyses are currently employed to determine which TPS are expressed in the berry and determine the terpenoid profile of the specific cultivar. These findings shed light on the genomic determinants of grape aroma in major cultivars, and allow future studies focused on cultivar-specific responses of terpenoid biosynthesis to environmental stresses.

Grapevine (Vitis vinifera L.) is one of the most important economic crops in the world. Because of this importance, one finds widespread molecular genetic research on this species, an important element of which is high quality RNA.

The addition of partially dehydrated grapes to enrich must composition for producing complex dry/sweet wines represents a traditional practice in several regions of the world. However, the environmental conditions of dehydration chambers may facilitate the infection of Botrytis cinerea Pers. by promoting disease and provoking large grape losses. B. cinerea attack can induce alterations in the profile of volatile organic compounds (VOCs), which could be detected by sensors specifically trained to detect infection/disease-related compounds. These sensors could facilitate the early detection of the infection, consequently allowing to adjust some dehydration parameters.