These-LeaRoch-19122018

Wednesday December 19, 2018 at 2:00 pm - Amphitheater Colette and Josy Bové - INRA Bordeaux - Defense of Thesis Léa ROCH

"Integrative and comparative study of primary metabolism of different fleshy fruit species during their development"

Léa ROCH

Team : Metabolism

Direction : Yves GIBON

Abstract: The world fruit market represents hundreds of billions of euros per year and improving the organoleptic and nutritional quality of fruit has been one of the main objectives in recent years. Primary metabolism is a target that can be used to try and meet these requirements. Indeed, it provides the bricks necessary for growth and development but also the compounds that contribute to taste such as sugars and organic acids. Therefore, it is necessary to understand how it operates during fruit development. For this purpose, primary metabolism has been studied in eight species of fleshy fruits that differ in terms of development duration, fruit size, botanical family, taste quality (sweetness, acidity, etc.),  and are subject or not to a respiratory crisis at the initiation of ripening. Physiological and biochemical data have been collected throughout the fruit development from anthesis to physiological maturity. Fruit growth modelling allowed standardizing the stages of development and thus improved comparison between species. The composition of biomass was then characterized qualitatively and quantitatively by targeted and non-targeted analytical approaches highlighting similarities and differences in composition and changes during development. Generalized linear models combining composition and growth data were used to compare different phases of fruit development and a discriminant partial least square regression analysis (PLS-DA) was used to separate climacteric and non-climacteric fruits. In both cases, cell wall compounds, proteins and lipids were involved in group differentiation. Finally, a detailed study of the fruit metabolome and activome was performed in three species of Solanaceae. It revealed that within the same botanical family, regulation differs during development, particularly for sugar metabolism and glycolysis. This work revisits the climacteric character of fruits, positioning it long before the onset of the respiratory crisis, and, more generally, provides a better understanding of primary metabolism during fruit development.

Jury :

M. Yves GIBON - DR INRA Bordeaux
M. Alain BOUCHEREAU - PR Université Rennes 1
M. François MESNARD - PR Université de Picardie
Mme Nathalie OLLAT - IR INRA Bordeaux
Mme Julia BUITINK - DR INRA Angers
Mme Annick MOING - DR INRA Bordeaux - invited member

Modification date : 14 August 2023 | Publication date : 19 November 2018 | Redactor : M. Gauthier