Developmental, molecular and genetic bases of the grapevine adaptation to thermal stress. – DURAVITIS

Abstract

The grapevine, like other important crop species, is faced to the effects of ongoing and predicted climate change, for instance of temperature increase. Temperature is well-known factor involved in grapevine vegetative and reproductive developments with important consequences for wines yields and quality. Temperature increase has already been shown to alter yield components (eg: flowers initiation, anthesis, flower and berry abortions) and wine quality (taste (acid balance), aspect (anthocyanidin pigmentation), flavors (aroma precursors) and nutritional properties (antioxidant properties, ethanol content).

Plant breeding combined with molecular plant biotechnology have the potential to deliver stable yields and quality under warmer climate conditions, but this requires the identification of key traits of tolerance to heat and their incorporation into new cultivars. In order to success in such tasks, the mechanisms of grapevine response to thermal stress need to be better understood and traits of adaptation need to be identified. The central goal of the DURAVITIS project is to re-evaluate the impact of temperature on grapevine vegetative and reproductive developments, through various angles of analysis including whole plant and microenvironment levels. A developmental analysis framework will be established to investigate the complex processes involved in microvine adaptation to temperature (C flow, berry respiration and metabolisms). Another goal of DURAVITIS is to identify genetic traits of temperature tolerance in grapevine screening of Vitis germplasm.

Given the various objectives of this project and the complexity of analyzing grapevine response to temperature in terms of vegetative and reproductive developments, this project is designed in a multidisciplinary research format involving ecophysiologists, molecular physiologists and geneticists. We believe that the release of high-throughput grapevine genomic tools and the development of innovative experimental approaches (fruiting cuttings, microvine) will help to dissect ecophysiological and molecular mechanisms underlying grapevine adaptative responses to high temperature, and facilitate the identification of genetic traits of heat tolerance. Several outcomes are expected to be produced in DURAVITIS, including:

i) Scientific advances - DURAVITIS is expected to release original information about these aspects in perennial fruit crops leading to a major breakthrough in the comprehension of fruiting plant responses to environmental constraints.

ii) Technical outcomes - The DURAVITIS project proposes a new methodological format based on the use of fruiting cuttings and microvines to accelerate and improve both ecophysiology and genetic investigations. By-passing several experimental drawbacks associated with traditional grapevines, this project offers the possibility to establish a phenotypic pipeline that may ultimately be used to address a range of questions related to grapevine adaptation to environmental stresses.

iii) Economical opportunities - The selection of new cultivars capable of withstanding climate warming while retaining quality appears to be most efficient and sustainable approach in a long-term perspective. The studies proposed in the DURAVITIS project are a pre-requisite to establish the principles for phenotypic analysis and for the selection of tolerant genotypes to temperature. Such tools are critical to initiate or design breeding programs for cultivar selection to temperature tolerance.