terclim by ICS banner
IVES 9 IVES Conference Series 9 International Congress on Grapevine and Wine Sciences 9 2ICGWS-2023 9 Identification of a stable epi-allele associated with flower development and low bunch compactness in a somatic variant of Tempranillo Tinto

Identification of a stable epi-allele associated with flower development and low bunch compactness in a somatic variant of Tempranillo Tinto

Abstract

Grapevine cultivars are vegetatively propagated to preserve their varietal characteristics. However, spontaneous somatic variations that occur and are maintained during cycles of vegetative growth offer opportunities for the natural improvement of traditional grape cultivars. One advantageous trait for winegrowing is reduced bunch compactness, which decreases the susceptibility to pests and fungal diseases and favor an even berry ripening. In this study, we examined a loose bunch somatic variant of Tempranillo Tinto cultivar (TT) to elucidate the molecular basis underlying this variation. The variant displayed a masculinized flower phenotype, characterized by an underdeveloped yet functional gynoecium, with reduced development of the style, stigma and septum, as compared to the complete hermaphroditic flowers typically observed in TT. Genetic analysis of its self-progeny demonstrated the co-segregation of the masculinized flower phenotype with the hermaphrodite allele of the grape sex locus (SDR)[1]. While genome re-sequencing did not identify any genetic variation within the SDR locus, an RNA-seq analysis identified one SDR-located gene over-expressed in the somatic variant compared to a control TT clone. The hermaphrodite allele was specifically over-expressed in the variant. Both Illumina WGBS and Nanopore epigenomic analyses identified a hermaphrodite allele-specific hyper-methylated region upstream of the upregulated gene. Analysis of chromatin conformation capture (3C) revealed a three-dimensional rearrangement of the locus, including the presence of a novel 36 kb chromatin loop delimiting the hyper-methylated region, which could be responsible for the over-expression and the phenotype. These findings indicate that somatic epi-alleles in the SDR locus can determine variation in gynoecium development leading to decreased fruit set and looser bunches in grapevine.

Acknowledgements: This study is part of the projects BIO-2017-86375-R and PID2020-120183RB-I00, and PRE-2018-086017 grant funded by MCIN/AEI/10.13039/501100011033 and by “ERDF A way of making Europe”. This study is also part of the vWISE project.

1)  Massonnet, M., Cochetel, N., Minio, A., Vondras, A. M., Lin, J., Muyle, A., Garcia, J. F., Zhou, Y., Delledonne, M., Riaz, S., Figueroa-Balderas, R., Gaut, B. S., & Cantu, D. (2020). The genetic basis of sex determination in grapes. Nature Communications, 11(1), 1–12. DOI: 10.1038/s41467-020-16700-z

DOI:

Publication date: October 4, 2023

Issue: ICGWS 2023

Type: Article

Authors

Alañón, Noelia1*; Ferradás, Yolanda2; Lijavetzky, Diego3; Ferrero, Lucía4; Martínez-Zapater, José Miguel1; Ariel, Federico4; Carbonell-Bejerano, Pablo1; Ibáñez, Javier1

1 Instituto de Ciencias de la Vid y del Vino (ICVV, CSIC-CAR-UR), Departamento de Viticultura, Logroño, Spain
2 Departamento de Biología Funcional, Universidad de Santiago de Compostela, Santiago de Compostela, Spain
3 Instituto de Biología Agrícola de Mendoza (IBAM), CONICET, FCA-UNCuyo, Almirante Brown 500, M5528AHB, Chacras de Coria, Mendoza, Argentina
4 Instituto de Agrobiotecnología del Litoral, CONICET, Universidad Nacional del Litoral, Colectora Ruta Nacional 168km 0, 3000, Santa Fe, Argentina

Contact the author*

Keywords

bunch compactness, somatic variation, flower development, chromatin conformation, epiallele

Tags

2ICGWS | ICGWS | ICGWS 2023 | IVES Conference Series

Citation

Related articles…

Implications of the nature of organic mulches used in vineyards on grapevine water status, yield, berry quality and biological soil health  

Climate emergency is going to affect the agricultural suistainability, wine grapes being probably one of the crops more sensitive to environmental constraints. In this context, mitigation strategies such as the revalorization of agricultural wastes are paramount to cope with the current challenges. The use of organic mulches has been reported to reduce soil water evaporation and improve vine water status, reduce soil erosion, and increase soil organic matter with little impact on berry quality. However, less is known about their effects on the microbiote of vineyards.

is the overall ecological awarness among Spanish winemakers related to their attitudes towards natural wines?

The Agenda 2030 of the EU sets out the main guidelines for transitioning towards a resilient, green and safe economy. To this regard, the wine sector is experiencing an ecological transition in different ways such as increasing the production of ecological crops, or promoting the production of wines under more environmental-friendly and healthier (i.e., lower levels of SO2) products. These alternatives to conventional production are a smaller proportion of wines, in constant growth and demand, and follow alternative and minority practices, which range from sustainable to deeply philosophical thoughts. Among these methods there are organic, biodynamic and, more recently, natural wines.

Evaluation of Furmint clones in the Tokaj Wine Region

The ’Furmint’ is the most important grape variety in the Tokaj Wine Region, constituting around 65% of its vineyard area. Before the phylloxera disease many types were grown, but as selection started in the 20th century, its diversity dramatically narrowed. As a result, the cultivation of Furmint was based mainly on two heavy-cropping clones, T.85 and T.92 at the end of the ’80s. Aims of present clone research take into account that after solely quantity as target, quality emerged in the 1990’s and most recently, typicity appeared as more private estates began their own selection program.

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.

Inert gases persistence in wine storage tank blanketing

It is common to find tanks in the winery with wine below their capacity due to wine transfers between tanks of different capacities or the interruption of operations for periods of a few days. This situation implies the existence of an ullage space in the tank with prolonged contact with the wine causing its absorption/oxidation. Oxygen uptake from the air headspace over the wine due to differences in the partial pressure of O2 can be rapid, up to 1.5 mL of O2 per liter of wine in one hour and 100 cm2 of surface area1 and up to saturation after 4 hours.