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…

Late winter pruning induces a maturity delay under temperature-increased conditions in cv. Merlot from Chile

Chile is considered vulnerable to climate change; and these phenomena affect several mechanisms in the grape physiology and quality. The global temperature increase affects sugar contents, organic acids, and phenolic compounds in grapes, producing an imbalance maturity. In this sense, an alternative to reduce the impact is to perform pruning after vine budburst, known as “Late Pruning” (LP).

Wine racking in the winery and the use of inerting gases

The O2 uptake in the different winemaking processes is generally considered to be negative for the sensory characteristics of white and rosé wines. Wine racking is a critical point of O2 uptake, as the large surface area of the wine exposed during this operation and the inability to maintain an effective inert gas blanket over it.
The objective was to study O2 uptake during the racking of a model wine without using inert gases and to compare it with the purging of the destination tank with different inert gases.

Investigation of cellulose nanofiber-based films used as a protective layer to reduce absorption of smoke phenols into wine grapes

Volatile phenols from wildfire smoke are absorbed by wine grapes, resulting in undesirable smoky and ashy sensory attributes in the affected wine.[1] Unfortunately the severity of wildfires is increasing, particularly when grapes are ripening on the vine. The unwanted flavors of the wine prompted a need for solutions to prevent the uptake of smoke compounds into wine grapes. Films using cellulose nanofibers as the coating forming matrix were developed as an innovative means to prevent smoke phenols from entering Pinot noir grapes. Different film formulations were tested by incorporating low methoxy pectin or chitosan.

The effect of ozonated water treatment on the metabolic profile and resistance of vines to Downy and powdery mildew 

Ozone is a potent oxidizing compound that quickly decomposes into oxygen without residues. Previous works reported that ozone is not only a disinfectant that directly harms the pathogens of the vine but also activates systemic defense systems in the plant by activating oxidative stress. We assume these systemic defense mechanisms are essential to the vines’ resistance to downy and powdery mildew (Plasmopara viticola & Erysiphe necator, respectively). The goals of the research are to examine the effect of spraying with ozone water on the plant’s resistance against the mentioned pathogens as well as to characterize the metabolic profile of the plants treated with ozone as well as physiological characteristics in the vines such as the level of Photosynthesis and crop yield. Vines in the vineyard sprayed with ozone water at concentrations of 2 and 4 PPM weekly and biweekly, untreated control & conventional spray. Leaves were taken from vines 2,4,7,9 and 11 days after exposure to ozone and inoculated with the pathogens.

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.