Effect of long-term deficit irrigation on tomato and goji berry quality: from fruit composition to in vitro bioaccessibility of carotenoids

Drought is a persistent challenge for horticulture, affecting various aspects of fruit development and ultimately fruit quality, but the effect on nutritional value has been under-investigated. Here, fruit quality was studied on six tomato genotypes and one goji cultivar under deficit irrigation (DI), from fruit composition to in vitro bioaccessibility of carotenoids. For both species, DI concentrated most health-related metabolites in fresh fruit. On a dry mass basis, DI increased total phenolic and sugar concentration, but had a negative or insignificant impact on fruit ascorbic acid, organic acid, and alcohol-insoluble matter contents. DI also reduced total carotenoids content in tomato (−18.7% on average), especially β-carotene (−32%), but not in goji berry DW (+15.5% and +19.6%, respectively). DI reduced the overall in vitro bioaccessibility of carotenoids to varying degrees depending on the compound and plant species. Consequently, mixed micelles produced by digestion of fruits subjected to DI contained either the same or lesser quantities of carotenoids, even though fresh fruits could contain similar or higher quantities. Thus, DI effects on fruit composition were species and genotype dependent, but an increase in the metabolite concentration did not necessarily translate into greater bioaccessibility potentially due to interactions with the fruit matri

An ecophysiological model of plant-nematodes interactions

International audienceLes nématodes à galles du genre Meloidogyne sont extrêmement polyphages et s’attaquent aux ra-cines de plantes en formant des protubérances racinaires appelées “galles”. Les galles entraînent uneréduction progressive de la fonctionnalité de l’appareil racinaire, réduisant la croissance et le rendementdes plantes, pouvant aller jusqu’à sa mort.Afin de mieux comprendre les mécanismes mis en jeu dans le cas d’une infection parMeloidogyne, nous avons proposé première approche de modélisation qui repose sur la description du partage de ressources entre plante et nématodes.. Nous nous sommesconcentrés sur deux effets visibles et mesurés au niveau des galles : le détournement du carbone racinaire et la résistanceamplifié du flux hydrique du sol vers les racines. N’ayant pas de données sur ces effets, nous avonschoisi de les écrire comme étant linéairement corrélés avec le nombre de nématodes. Les limites et perspectives de ce travail sont discutés

Improving crop sustainability and fresh and processed fruit quality through integrated analyses along the food chain

International audienceWhile million people lack access to food or some nutrients, up to one-third of food is never consumed, especially fruit and vegetables, naturally rich in phytonutrients. Fruit and vegetables waste and loss arise at all steps of the food chain from production to consumption. The access to phytonutrients is also threatened with climate changes that impact both yields and the composition of harvested organs. Finding trade-offs between yield and quality along the food chain appears necessary to improve crop sustainability and to limit losses. Processing tomato is a good target to address these challenges: it is a major crop and an important source of phytonutrients notably phenolic compounds and carotenoids, and it represents an intensive production in terms of water use. Two examples of integrated analyses will be given. First, we will focus on pre-postharvest relationships and the ability of tomatoes to be processed into purees. We investigated fruit quality in response to water supply, genotypes and ripening stage, and we assessed their impact on puree obtained from hot break and cold break processes. We found that fruit growth and quality were weakly impacted by moderate water insufficiency during growth. A reduction of water supply from 100% to 60% of the evapotranspiration strongly impacted plant growth but had little impact on fresh fruit yield and increased the water use efficiency by 20%. Second, we address the accumulation of carotenoids in ripe tomato in response to water insufficiency in two genotypes. A medium water deficit (-0.5 MPa soil water potential while permanent wilting point is estimated at-1,5 MPa) at the beginning of fruit development impacted the fruit composition at maturity. The dry matter contents increased up to 23% while an interaction between genotype and water regime was found for carotenoid contents which may affect tomato health value

Effect of long-term deficit irrigation on tomato and goji berry quality: from fruit composition to in vitro bioaccessibility of carotenoids

International audienceDrought is a persistent challenge for horticulture, affecting various aspects of fruit development and ultimately fruit quality, but the effect on nutritional value has been under-investigated. Here, fruit quality was studied on six tomato genotypes and one goji cultivar under deficit irrigation (DI), from fruit composition to in vitro bioaccessibility of carotenoids. For both species, DI concentrated most health-related metabolites in fresh fruit. On a dry mass basis, DI increased total phenolic and sugar concentration, but had a negative or insignificant impact on fruit ascorbic acid, organic acid, and alcohol-insoluble matter contents. DI also reduced total carotenoids content in tomato (−18.7% on average), especially β-carotene (−32%), but not in goji berry DW (+15.5% and +19.6%, respectively). DI reduced the overall in vitro bioaccessibility of carotenoids to varying degrees depending on the compound and plant species. Consequently, mixed micelles produced by digestion of fruits subjected to DI contained either the same or lesser quantities of carotenoids, even though fresh fruits could contain similar or higher quantities. Thus, DI effects on fruit composition were species and genotype dependent, but an increase in the metabolite concentration did not necessarily translate into greater bioaccessibility potentially due to interactions with the fruit matri

DataSheet_1_Effect of long-term deficit irrigation on tomato and goji berry quality: from fruit composition to in vitro bioaccessibility of carotenoids.pdf

Drought is a persistent challenge for horticulture, affecting various aspects of fruit development and ultimately fruit quality, but the effect on nutritional value has been under-investigated. Here, fruit quality was studied on six tomato genotypes and one goji cultivar under deficit irrigation (DI), from fruit composition to in vitro bioaccessibility of carotenoids. For both species, DI concentrated most health-related metabolites in fresh fruit. On a dry mass basis, DI increased total phenolic and sugar concentration, but had a negative or insignificant impact on fruit ascorbic acid, organic acid, and alcohol-insoluble matter contents. DI also reduced total carotenoids content in tomato (−18.7% on average), especially β-carotene (−32%), but not in goji berry DW (+15.5% and +19.6%, respectively). DI reduced the overall in vitro bioaccessibility of carotenoids to varying degrees depending on the compound and plant species. Consequently, mixed micelles produced by digestion of fruits subjected to DI contained either the same or lesser quantities of carotenoids, even though fresh fruits could contain similar or higher quantities. Thus, DI effects on fruit composition were species and genotype dependent, but an increase in the metabolite concentration did not necessarily translate into greater bioaccessibility potentially due to interactions with the fruit matrix</p

Human Engineered Heart Tissue: Analysis of Contractile Force

Analyzing contractile force, the most important and best understood function of cardiomyocytes in vivo is not established in human induced pluripotent stem cell-derived cardiomyocytes (hiPSC-CM). This study describes the generation of 3D, strip-format, force-generating engineered heart tissues (EHT) from hiPSC-CM and their physiological and pharmacological properties. CM were differentiated from hiPSC by a growth factor-based three-stage protocol. EHTs were generated and analyzed histologically and functionally. HiPSC-CM in EHTs showed well-developed sarcomeric organization and alignment, and frequent mitochondria. Systematic contractility analysis (26 concentration-response curves) reveals that EHTs replicated canonical response to physiological and pharmacological regulators of inotropy, membrane-and calcium-clock mediators of pacemaking, modulators of ion-channel currents, and proarrhythmic compounds with unprecedented precision. The analysis demonstrates a high degree of similarity between hiPSC-CM in EHT format and native human heart tissue, indicating that human EHTs are useful for preclinical drug testing and disease modeling

Differentiation of cardiomyocytes and generation of human engineered heart tissue

Since the advent of the generation of human induced pluripotent stem cells (hiPSCs), numerous protocols have been developed to differentiate hiPSCs into cardiomyocytes and then subsequently assess their ability to recapitulate the properties of adult human cardiomyocytes. However, hiPSC-derived cardiomyocytes (hiPSC-CMs) are often assessed in single-cell assays. A shortcoming of these assays is the limited ability to characterize the physiological parameters of cardiomyocytes, such as contractile force, due to random orientations. This protocol describes the differentiation of cardiomyocytes from hiPSCs, which occurs within 14 d. After casting, cardiomyocytes undergo 3D assembly. This produces fibrin-based engineered heart tissues (EHTs) - in a strip format - that generate force under auxotonic stretch conditions. 10-15 d after casting, the EHTs can be used for contractility measurements. This protocol describes parallel expansion of hiPSCs; standardized generation of defined embryoid bodies, growth factor and small-molecule-based cardiac differentiation; and standardized generation of EHTs. To carry out the protocol, experience in advanced cell culture techniques is required