terclim by ICS banner
IVES 9 IVES Conference Series 9 GiESCO 9 GiESCO 2023 9 The real sour grapes: genetic Loci, genes, and metabolic changes associated with grape malate levels

The real sour grapes: genetic Loci, genes, and metabolic changes associated with grape malate levels

Abstract

Context and purpose of the study – Insufficient levels of malate and lack of acidity in commercial grape cultivars (V.vinifera) hinders the quality of fruit grown in warm climates. Conversely, excessive levels of malate and sourness in wild Vitis grape, leads to unpalatable fruit and complicates the introgression of valuable disease resistant alleles through breeding. Nonetheless, albeit decades of research, knowledge regarding the molecular regulation of malate levels in grape remains limited.
While malate dissimilation is a hallmark of grape ripening, it was found to be absent or limited in wild Vitis fruit (riparia, cinerea). Hence, these genotypes serve as unique resources to deepen our understanding of malate regulation, with the overarching goal of controlling fruit acidity by breeding.
Our research aimed to (i) Identify genetic loci tightly associated with fruit malate levels in interspecific families, and (ii) highlight differences in metabolism and gene expression, associated with contrasting malate behavior between wild and commercial genotypes.

Material and methods – QTL mapping was performed using a novel set of amplicon-based markers (rhAmpSeq) and six years of phenotyping of a complex interspecific F1 family with strong and stable variation in malate at ripeness. In addition, a comparative RNAseq and primary metabolite profiling was performed during fruit development in riparia and cinerea accessions, and commercial vinifera cultivars.

Results – Three significant QTL for ripe fruit malate on chromosomes 1, 7, and 17, accounted for over two-fold and 6.9 g/L differences, and explained 40.6% of the phenotypic variation. QTL on chromosomes 7 and 17 were stable in all and in three out of five years, respectively. Lack of malate degradation in wild genotypes was associated with higher fruit respiration rates, higher levels of amino acids, TCA and fermentation metabolites, and higher expression of their corresponding genes, some of which positioned within the identified QTL in the studied population.
The developmental pattern and inter-specific differences in the expression of genes presumably  involved in malate biostynthesis, degradation, and transport, allowed us to highlight major candidate genes involved in malate regulation across Vitis species. These results advance current knowledge regarding the regulation of malate at the mechanistic and metabolic levels, and highlight genetic markers and candidate genes associated with grape acidity.

DOI:

Publication date: June 20, 2023

Issue: GiESCO 2023

Type: Article

Authors

Noam Reshef1α*, Avinash Karn2, Noga Sikron3, Al Shoffe Y2, David C. Manns4, Anna Katharine Mansfield4, Bill Miller2, Chris Watkins2, Lance Cadle-Davidson5, Bruce Reisch2, Aaron Fait3, Jason Londo5, and Gavin L. Sacks1

1 Department of Food Science, Cornell University, Ithaca, NY, USA
2 Horticulture Section, School of Integrative Plant Science, Cornell University, Geneva, NY, USA
3 Jacob Blaustein Institutes for Desert Research, Ben-Gurion University of the Negev, Israel
4 Department of Food Science, Cornell AgriTech, Geneva, NY, USA
5 USDA-ARS, Grape Genetics Research Unit, Geneva, NY, USA

α Current address: Department of Fruit Tree Sciences, Institute of Plant Sciences, Agricultural Research Organization, Israel

Contact the author*

Keywords

fruit acidity, wild Vitis, marker-assisted breeding, rhAmpSeq, vacuolar transport, climate-change adaptation, disease resistance

Tags

GiESCO | GIESCO 2023 | IVES Conference Series

Citation

Related articles…

Physiological and growth reaction of Shiraz/101-14 Mgt to row orientation and soil water status

Advanced knowledge on grapevine row orientation is required to improve establishment, management and outcomes of vineyards on terroirs with different environmental conditions (climate, soil, topography) and in view of a future change to more extreme climatic conditions. The purpose of this study was to determine the combined effect of row orientation, plant water status and ripeness level on the physiological and viticultural reaction of Shiraz/101-14 Mgt.

Effects of mechanical leafing and deficit irrigation on Cabernet Sauvignon grown in warm climate of California

San Joaquin Valley accounts for 40% of wine grape acreage and produces 70% of wine grape in California. Fruit quality is one of most important factors which impact the economical sustainability of farming wine grapes in this region. Due to the recent drought and expected labor cost increase, the wine industry is thrilled to understand how to improve fruit quality while maintaining the yield with less water and labor input. The present study aims to study the interactive effects of mechanical leafing and deficit irrigation on yield and berry compositions of Cabernet Sauvignon grown in warm climate of California.

The effects of cane girdling on berry texture properties and the concentration of some aroma compounds in three table grape cultivars

The marketability of the table grapes is highly influenced by the consumer demand; therefore the market value of the table grapes is mainly characterized by its berry size, colour, taste and texture. Girdling could cause accumulation of several components in plants above the ringing of the phloem including clusters and resulting improved maturity. The aim of the experiments was to examine the effect of girdling on berry texture characteristics and aroma concentration.

Application of a fluorescence-based method to evaluate the ripening process and quality of Pinot Blanc grape

The chemical composition of grape berries at harvest is one of the most important factors that should be considered to produce high quality wines. Among the different chemical classes which characterize the grape juice, the polyphenolic compound, such as flavonoids, contribute to the final taste and color of wines. Recently, an innovative non-destructive method, based on chlorophyll fluorescence, was developed to estimate the phenolic maturity of red grape varieties through the evaluation of anthocyanins accumulated in the berry skin. To date, only few data are available about the application of this method on white grape varieties.

Different yield regulation strategies in semi-minimal-pruned hedge (SMPH) and impact on bunch architecture

Yields in the novel viticulture training system Semi-Minimal-Pruned Hedge (SMPH) are generally higher compared to the traditional Vertical Shoot Positioning (VSP). Excessive yields have a negative impact on the vine and wine quality, which can result in substantial losses in yield in subsequent vintages (alternate bearing) or penalties in fruit quality. Therefore yield regulation is essential. The bunch architecture in SMPH differs from VSP. Generally there is a higher amount but smaller bunches with lower single berry weights in SMPH compared to VSP.