부산대학교 도서관

SUMMARY: Although primary metabolism is well conserved across species, it is useful to explore the specificity of its network to assess the extent to which some pathways may contribute to particular outcomes. Constraint‐based metabolic modelling is an established framework for predicting metabolic fluxes and phenotypes and helps to explore how the plant metabolic network delivers specific outcomes from temporal series. After describing the main physiological traits during fruit development, we confirmed the correlations between fruit relative growth rate (RGR), protein content and time to maturity. Then a constraint‐based method is applied to a panel of eight fruit species with a knowledge‐based metabolic model of heterotrophic cells describing a generic metabolic network of primary metabolism. The metabolic fluxes are estimated by constraining the model using a large set of metabolites and compounds quantified throughout fruit development. Multivariate analyses showed a clear common pattern of flux distribution during fruit development with differences between fast‐ and slow‐growing fruits. Only the latter fruits mobilise the tricarboxylic acid cycle in addition to glycolysis, leading to a higher rate of respiration. More surprisingly, to balance nitrogen, the model suggests, on the one hand, nitrogen uptake by nitrate reductase to support a high RGR at early stages of cucumber and, on the other hand, the accumulation of alkaloids during ripening of pepper and eggplant. Finally, building virtual fruits by combining 12 biomass compounds shows that the growth‐defence trade‐off is supported mainly by cell wall synthesis for fast‐growing fruits and by total polyphenols accumulation for slow‐growing fruits. Significance Statement: This work shows how a panel of eight fruit species unravels specific metabolic flux patterns throughout fruit development. For this, a medium‐size metabolic model of primary metabolism is constrained by compositional time‐series data. The predicted metabolic fluxes highlight a growth‐defence trade‐off with high nitrogen uptake and carbon used in cell wall synthesis for fast‐growing fruits from herbaceous plants. Conversely, slow‐growing fruits, from trees, require the tricarboxylic acid cycle for early phenolic compounds synthesis. [ABSTRACT FROM AUTHOR]