Fuente: PubMed "Tomato process" Plant Sci. 2025 Dec 8;364:112927. doi: 10.1016/j.plantsci.2025.112927. Online ahead of print.ABSTRACTViscosity is an important quality trait of processed tomato products such as tomato juice and ketchup. The viscosity is partially determined by the degree of pectin methylesterification regulated by pectin methylesterase (PME) where pectin methylesterase inhibitors (PMEIs) have been shown to play a key role in regulating PME activity. However, the specific role of PMEIs in regulating the viscosity of processed tomato products remains unexplored. In this study, we identified a candidate PMEI gene (SlPMEI3) in manipulating PME activity in ripe tomato fruit by gene expression analysis, molecular docking and prokaryotic verification. The function of SlPMEI3 was further investigated by genetic modification. The results showed that the overexpression of SlPMEI3 suppressed PME activity by 50 %, leading to a 50 % increase in pectin methyl esterification and resulting in the enhanced viscosity of tomato juice and ketchup. Furthermore, the overexpression of SlPMEI3 resulted in higher fruit pH values, as well as greater precipitation ratio of tomato fruit. The transgenic tomato plants with up-regulated PME activity were significantly taller with earlier flowering times. In addition, the transgenic fruit had greater pericarp ratio but had reduced fruit size, yield and seed number. In summary, this study showed that overexpression of SlPMEI3 enhanced the viscosity of processed tomato products which provide new insights and opportunities for targeted quality improvement for the tomato processing industry.PMID:41371553 | DOI:10.1016/j.plantsci.2025.112927