QTL mapping of the production of wine aroma compounds by yeast (original) (raw)

Identification Of Causal Genes Of mQTLs Associated To Grape and Wine Flavor

Secondary metabolites produced in grapevine berries play an essential role in high-quality wines and also contribute to the quality of table grapes. Some of the most prevalent wine odor constituents are monoterpenoids which biosynthesis via the plastidial methyl-erythritol-phosphate (MEP) pathway has been demonstrated in grapevine. Based on a double pseudo-testcross mapping strategy, we detected a major QTL on LG 5 for linalool, nerol and geraniol content in grapevine berries at ripening time, and also an additional QTL for linalool on LG 10. Further testing indicated that gain-of-function mutations in the structural gene of the MEP pathway 1-deoxy-D-xylulose-5-phosphate synthase (VvDXS1) - colocalized with the mQTL on chromosome 5 - are the major determinants for terpenoid accumulation in Muscat grape varieties and have direct effects on the enzymatic or regulatory properties of the DXS protein. Similarly, association of genetic variants with the content of several volatile aromati...

Novel wine yeast with ARO4 and TYR1 mutations that overproduce 'floral' aroma compounds 2-phenylethanol and 2-phenylethyl acetate

Applied microbiology and biotechnology, 2018

It is well established that the choice of yeast used to perform wine fermentation significantly influences the sensory attributes of wines; different yeast species and strains impart different profiles of esters, volatile fatty acids, higher alcohols, and volatile sulphur compounds. Indeed, choice of yeast remains one of the simplest means by which winemakers can modulate the sensory characteristics of wine. Consequently, there are more than 100 commercially available Saccharomyces cerevisiae wine yeast strains available, mostly derived by isolation from vineyards and successful fermentations. Nevertheless, some desirable characteristics such as 'rose' and 'floral' aromas in wine are not present amongst existing strains. Such aromas can be conferred from the higher alcohol 2-phenylethanol (2-PE) and its acetate ester, 2-phenylethyl acetate (2-PEA). These metabolites of the aromatic amino acid phenylalanine are present at concentrations below their aroma detection thr...

Grape terpenoids: flavor importance, genetic regulation, and future potential

Critical Reviews in Food Science and Nutrition, 2021

Terpenes significantly affect the flavor and quality of grapes and wine. This review summarizes recent research on terpenoids with regard to grape wine. Although, the grapevine terpene synthase gene family is the largest identified, genetic modifications involving terpenes to improve wine flavor have received little attention. Key enzyme modulation alters metabolite production. Over the last decade, the heterologous manipulation of grape glycosidase has been used to alter terpenoids, and cytochrome P450s may affect terpene synthesis. Metabolic and genetic engineering can further modify terpenoid metabolism, while using transgenic grapevines (trait transfer to the plant) could yield more flavorful wine. We also discuss traits involved in wine aroma quality, and the strategies that can be used to improve grapevine breeding technology.