Modelling malic acid accumulation in fruits: relationships with organic acids, potassium, and temperature

Abstract

Malic acid production, degradation, and storage during fruit development have been modelled. The model assumes that malic acid content is determined essentially by the conditions of its storage in the mesocarp cells, and provides a simplified representation of the mechanisms involved in the accumulation of malate in the vacuole and their regulation by thermodynamic constraints. Solving the corresponding system of equations made it possible to predict the malic acid content of the fruit as a function of organic acids, potassium concentration, and temperature. The model was applied to peach fruit, and parameters were estimated from the data of fruit development monitored over 2 years. The predictions were in good agreement with experimental data. Simulations were performed to analyse the behaviour of the model in response to variations in composition and temperature.

Not All Shrivels Are Created Equal—Morpho-Anatomical and Compositional Characteristics Differ among Different Shrivel Types That Develop during Ripening of Grape (<i>Vitis vinifera</i> L.) Berries

“…Such phenomenon implicitly suggests up-regulation of respiration as a temperature-sensitive malate metabolic pathway, due to the involvement of malate in this pathway during ripening [119]. Similar phenomenon ensuing from temperature-induced malic acid degradation occurs in peach [120] and apple [52]. In addition to dramatic decreases in malic acid, the sugar content also decreased in sunburned berries.…”

Inference and prediction of metabolic network fluxes

“…Accounting for the expansion phase of cell growth will require a consideration of the appropriate experimental measures that can be used as constraints. Given that expansion requires only limited synthesis of new biomass and is instead driven largely by osmotic uptake of water into the vacuole, these will center on the rates of vacuolar transport of ions and metabolites as the source of the osmotic driving force (Lobit et al, 2006). Methods have also been proposed that would allow the determination of isotopic label redistribution in specific cell types to support cell type-specific MFA (Kruger and Ratcliffe, 2015), although the low mass of dividing cells in organs such as roots and leaves would present a considerable sensitivity challenge for this cell type.…”

An InDel in the Promoter of Al-ACTIVATED MALATE TRANSPORTER9 Selected during Tomato Domestication Determines Fruit Malate Contents and Aluminum Tolerance

“…Enhanced malate concentrations lead to altered starch metabolism and soluble solid contents in tomato, which subsequently affects postharvest fruit softening (Centeno et al, 2011). Malate has also been shown to enhance the perception of sucrose during fruit consumption (Lobit et al, 2006). Thus, consumers and plant breeders have directly or indirectly selected for desirable malate contents during agricultural variety development in the past; however, the specific genotypes associated with malate trait selection remain uncharacterized (Ma et al, 2015a).…”