Growth and organ composition

   In the current context of climate change, the increasing occurrence of drought events associated or not with heat stress threatens yields, but it can also affect the concentration of phytomicronutrients (PMNs) in fruits, including carotenoids and phenolic compounds but also polysaccharides and minerals, depending on the genotype, intensity and duration of the water deficit (Ripoll et al., 2014; Constantinescu et al., 2016). Overall, these changes associated with water deficit may be beneficial for product processing, facilitating the dehydration/concentration step, but their effects on the quality of the final product and its sanitary value are unclear. Indeed, the impact of water deficit on the storage capacity of PMNs, or on PMNs-polysaccharide interactions has not been studied or has been poorly studied so far. Therefore, the production of high quality fruits for processing and for proven health effects requires the study of the mechanisms and factors involved at the cellular and subcellular levels. The aim is to select new cultivars but also to reason the practices in an integrated way from field to consumer. Modelling is a useful approach for integrating and analysing the complexity of the components studied. Currently, predictive models of fruit quality are mainly concerned with the metabolism and accumulation of sugars and acids, and there is a need to extend these models to predict key variables of fruit health value.

   In this context, we plan to study the accumulation and compartmentalisation of PMNs (carotenoids and phenolic compounds) in the fruit in relation to abiotic constraints (water in particular), using an experimental and biophysical modelling approach. We will be particularly interested in the mechanisms of cell division and growth (number and size of cells, number and size of plastids) which could determine a storage capacity for carotenoids and phenolic compounds. For this purpose, a combined approach based on confocal microscopy and image analysis is being developed. Secondly, based on the composition of the harvested products, we are seeking to determine the physical and chemical composition factors affecting both the bioaccessibility and bioavailability of PMNs in fresh and processed products in collaboration with the Transform department. Finally, beyond the composition, the health value differential created in the field is to be studied by analyses in mice in collaboration with the AlimH department.

   In the long term, our objectives are to provide knowledge and to develop models to control production and quality according to the destination of the products (conservation, fresh, processing) and thus to contribute to the reduction of harvest losses and to the optimisation of health effects via food and via the reduction of environmental impacts.

Publications :

Constantinescu D., Memmah M., Vercambre G., Génard M., Baldazzi V., Causse M., Albert E., Brunel B., Valsesia P., Bertin N. (2016). Model-Assisted Estimation of the Genetic Variability in Physiological Parameters Related to Tomato Fruit Growth under Contrasted Water Conditions. Frontiers in Plant Science, 7, np, https://dx.doi.org/10.3389/fpls.2016.01841

Ripoll J., Urban L., Staudt M., Lopez-Lauri F., Bidel L., Bertin N. (2014). Water shortage and quality of fleshy fruits--making the most of the unavoidable. Journal of Experimental Botany, 65 (15), 4097-4117, https://dx.doi.org/10.1093/jxb/eru197

Resources and Partnership :

Projects : Tomhealth ANR (2021-2025), projet Gojiqual 2021-2022, projet Quamisol MP Syalsa (2023-2025, AUBCOL).

Thesis : T. Breniere (2020-2023)

Post-doc : L. Miele (2022-2023)

Collaborations : UMRs SQPOV et OPAALE (dpt Transform), UMRs C2VN et MICALIS (dpt AlimH), université d’Avignon, le CTCPA et la SONITO.