Action of high concentration of carbon dioxide on size and ripening of tomato fruit

Abstract

Elevated carbon dioxide concentration (eCO2) has the potential to modify tomato fruit size. However, the role of eCO2 on the rate of fruit growth and the time of fruit ripening remains elusive. Here, we report that the decrease in number of cell per area in the pericarp of mature fruits was associated with a significant enhancement in cell area, which in turn increased fruit yield and concentration of minerals. Moreover, the maximal fruit expansion rate was increased by eCO2 conditions, which was associated with enhanced of transcripts encoding expansin proteins in pericarp tissues of immature fruits. However, the duration of fruit expansion was not affected by eCO2, suggesting that fruit expansion rate is more flexible than expansion duration upon eCO2 treatment. High CO2 increased concentrations of ethylene and carotenoids during fruit ripening, which resulted in a slight acceleration of maturation. Thus, our study highlights the potential role of eCO2 in determining tomato fruit size and ripening.