terclim by ICS banner
IVES 9 IVES Conference Series 9 International Congress on Grapevine and Wine Sciences 9 2ICGWS-2023 9 Identification of loci associated with specialised metabolites in Vitis vinifera

Identification of loci associated with specialised metabolites in Vitis vinifera

Abstract

Secondary (or specialised) metabolites such as terpenes and phenolic compounds are produced by plants for various roles which include defence against pathogens and herbivores, protection against abiotic stress, and plant signalling. Additionally, these metabolites influence grapevine quality traits such as colour, aroma, taste, and nutritional value. However, the biosynthesis of these metabolites is often complex and controlled by multiple genes which in grapevine are predominantly uncharacterised. This study therefore aimed to identify novel loci associated with grapevine volatile organic and phenolic compounds. Chemical analysis of these compound classes was performed via GC-MS and UPLC analysis in a grapevine mapping population, and the quantified metabolites used for quantitative trait loci (QTL) analysis.  Several significant QTLs associated with terpenes and phenolic compounds were identified, and the underlying genomic regions were investigated. For phenolic compounds, a novel locus associated with caftaric acid biosynthesis was identified, and a hydroxycinnamoyltransferase (VvHCT) was investigated as a candidate gene. Several terpene synthases (VvTPSs) co-localised with QTLs associated with monoterpenes and sesquiterpenes. Notably, loci on chromosomes 12 and 13 were shown to be associated with geraniol and cyclic monoterpene accumulation, respectively. The locus on chromosome 12 was shown to contain a geraniol synthase gene (VvGer), while the locus on chromosome 13 contained an a-terpineol synthase gene (VvTer). Further molecular and genomic investigation of VvGer and VvTer found that these genes appear in tandemly duplicated clusters, with high levels of hemizygosity which was further supported by genomic data from recently published diploid grapevine genomes. Interestingly, copy number analysis demonstrated that VvTer gene copy number correlated with both VvTerexpression and the accumulation of cyclic monoterpenes, highlighting the impact of VvTPS gene duplication and copy number variation on terpene accumulation in grapevine.

DOI:

Publication date: October 3, 2023

Issue: ICGWS 2023

Type: Article

Authors

Robin Bosman*1 and Justin Graham Lashbrooke2

1South African Grape and Wine Research Institute, Stellenbosch University, Stellenbosch, South Africa
2 Department of Genetics, Stellenbosch University, South Africa.

Contact the author*

Keywords

terpenes, TPS, grapevine, gene copy number, genomics, QTL, phenolics

Tags

2ICGWS | ICGWS | ICGWS 2023 | IVES Conference Series

Citation

Related articles…

Characterization of non-cultivated wild grapevines in Extremadura (Spain) 

Several Eurasian wild grapevine populations were found along Extremadura region (southwestern Spain). For conservation and study, one individual from four different populations (named L1, L2, L5 and L6) was vegetatively propagated and planted at Instituto de Investigaciones Agrarias Finca La Orden (CICYTEX), Badajoz. The aim of the present work was to characterize those conserved individuals from four different populations based on both an ampelographic description and a molecular analysis. Three vines per individual were studied.

Energy partitioning and functionality of photosystem II in water-stressed grapevines during heatwaves revealed by continuous measurements of chlorophyll fluorescence

The increased intensity and frequency of heatwaves, coupled with prolonged periods of drought, are a significant threat to viticulture worldwide. During these conditions the more exposed leaves can show visible symptoms of heat damage. We monitored the functionality of photosystem II (PSII) in the field to better understand the impact of heatwaves on canopy performance. A factorial experiment was established in summer 2023 using Shiraz grapevines in the Barossa valley of South Australia, involving water-stressed and well-watered vines.

New food trend ahead? Highlighting the nutritional benefits of grapevine leaves

The wine industry produces an enormous amount of waste every year. A wider inclusion of disregarded by-products in the human diet or its use as a source of bioactive compounds is a good strategy for reducing waste. It will not only introduce an added value to a waste product but also come upon the European Union and United Nations’ demands towards more sustainable agricultural approaches and circular economy.

Evaluation of physiological properties of grapevine clones of ‘Tempranillo’ and ‘Graciano’ in DOCa Rioja (Spain)

In order to avoid the loss of grapevine intra-varietal diversity of DOCa Rioja grape varieties, Regional Government of La Rioja established a germplasm bank with more than 1.600 accessions, whose origin lies in the prospecting and sampling of ancient vineyards located throughout the whole region. 30 clones of Tempranillo and 13 clones of Graciano were preselected and multiplied in a new vineyard for further observations. The aim of this work is to describe the first results from the physiological characterization by an optical sensor of these preselected clones, which constitute the base of a new clonal selection that aims to increase the range of available certified clones and to improve the adaptation of these varieties to future objectives and environmental conditions.

Accumulation of deleterious mutations in grapevine and its relationship with traits of interest for wine production and resilience

Deleterious mutations that severely reduce population fitness are rapidly removed from the gene pool by purifying selection. However, evolutionary drivers such as genetic drift brought about by demographic bottlenecks may comprise its efficacy by allowing deleterious mutations to accumulate, thereby limiting the adaptive potential of populations. Moreover, positive selection can hitchhike mildly deleterious mutations due to linkage caused by lack of recombination. Similarly, in the context of species domestication, artificial selection mimics these evolutionary processes, which can have undesirable consequences for production and resilience. In this study, we evaluated the extent of the accumulation of deleterious mutations and the magnitude of their effects (also known as genetic load) at the whole-genome scale for ca.