Vitis vinifera L. Diversity for Cations and Acidity Is Suitable for Breeding Fruits Coping With Climate Warming

Abstract

The selection of grapevine varieties is considered to be the smartest strategy for adapting the viticulture to climate warming. Present knowledge of the diversity of grape solutes known to be influenced by temperature is too limited to perform genetic improvement strategies. This study aimed to characterize the diversity for major cations (K + , Mg 2+ , Ca 2+ , NH 4 +) of the Vitis vinifera fruit and their effect on acidity. Two developmental stages were targeted: the end of green growth, when organic acids reach a maximum, and the physiological ripe stage defined by the stopping of solutes and water import at the maximum volume of the berry. Twelve varieties and 21 microvines from the same segregating population were selected from preliminary phenotyping. The concentration of cations depended on the stage of fruit development, the genotype and the environment with GxE effects. In the ripe grape, K + concentration varied from 28 to 57 mmol.L-1 with other cations being less concentrated. Combined with the variation in organic acids, cation concentration diversity resulted in titratable acidity of the ripe fruit ranging from 38 to 215 meq.L-1. These results open new perspectives for the selection of varieties to mitigate the adverse effects of climate warming on grape quality.

Transcripts switched off at the stop of phloem unloading highlight the energy efficiency of sugar import in the ripeningV. viniferafruit

“…At phloem arrest, with a malate concentration below 100 mEq (39 in Syrah, 48 and 93 mEq in MV032 and MV102), the berry already consumed between 60 and 80% of the malic acid accumulated before softening. These differences in acidity that would principally originate from the green stage accumulation period 27 did not apparently interfere with phloem arrest.…”

“…S1). Although MV032 and MV102 were classified as high sugar accumulator genotypes among a segregating microvine population 26 , they showed a 35% lower sugar concentration at phloem arrest ( Fig. 1, Table S1).…”

“…At phloem arrest, with a malate concentration below 100 mEq (39 in Syrah, 48 and 93 mEq in MV032 and MV102), the berry already consumed between 60 and 80% of the malic acid accumulated before softening. These differences in acidity that would principally originate from the green stage accumulation period26 did not apparently interfere with phloem arrest.Our study, performed in two environments and in three genotypes displaying different ripening features, reports for the first time robust gene trajectories associated with the end of the sugar and water accumulation processes, with the most intensively down-regulated genes related to cell wall modification (arrest of growth), aquaporins and sugar transporters (arrest of phloem unloading). The prevalence of plasma-membrane channels and transporters genes virtually turned off at phloem arrest re-emphasizes the central role of the apoplasmic pathway in ripening…”

Transcripts switched off at the stop of phloem unloading highlight the energy efficiency of sugar import in the ripening V. vinifera fruit

“…S1 ). Although MV032 and MV102 were classified as high sugar accumulator genotypes among a segregating microvine population 27 , they showed a 35% lower sugar concentration at phloem arrest (Fig. 1 and Table S1 ).…”

The Application of Ozonated Water Rearranges the Transcriptome of the Vitis Vinifera L. Fruit

“…Carrying the Vvigai1 mutation, microvines exhibit a continuous owering, simultaneously displaying all the successive stages of fruit development on a single shoot 15 . This model has already facilitated transcriptomics approaches of the circadian cycle 16 , high-temperature stresses 17,18 , metabolomics works surveying glycosylated aroma precursors 19,20 , and several berry developmental studies [21][22][23] .…”