ORIGINAL PAPER Increased Postharvest Life of TomLox B Silenced Mutants of Tomato (Solanum lycopersicum) Var. TA234 Elizabeth León-García 1 & Gilber Vela-Gutiérrez 1 & Oscar A. Del Ángel-Coronel 1 & Cristobal Torres-Palacios 1 & Javier De La Cruz-Medina 1 & Miguel A. Gómez-Lim 2 & Hugo Sergio García 1 # Springer Science+Business Media, LLC 2017 Abstract A healthy lifestyle includes fruits and vegetables consumption. Tomato is one of the most consumed vegeta- bles, although it is susceptible to physical damage through postharvest handling, thus leading to important losses. Softening is an important variable during tomato ripening; excessive softening is undesirable and leads to postharvest losses. TomloxB plays an important role in ripening, mainly in the loss of cellular integrity caused by fatty acids released from the lipid matrix of membranes that initiate oxidative deterioration, which is in turn carried into senescence. In order to increase postharvest life, we produced transgenic tomato plants via Rhizobium radiobacter with tomato lipoxygenase B (TomloxB) antisense constructs under control of the cauli- flower mosaic virus (CaMV) 35S promoter. Lipoxygenase activity and firmness were measured in tomato fruit and the fatty acids profile was determined. Transgenic fruits were maintained for 40 days at room temperature in optimal condi- tions, whereas wild type fruits remained in similar conditions for only six days. Firmness in pink and red stages was signif- icantly lower in wild type fruits than in two transgenic lines. Linolenic acid was the most important fatty acid consumed by lipoxygenase in both turning and pink stages of ripening. Lipoxygenase activity was smaller in transformed fruits in comparison with the wild type. These results suggest that silencing the TomloxB gene promoted significant changes in the physiology of transformed tomatoes, being the increase in postharvest life the most important. Keywords Tomlox B . Tomato transgenic . Postharvest life . Ripening delaying Abbreviations TomloxB Lipoxygenase B in tomato fruit CaMV Cauliflower mosaic virus LOX Lipoxygenase PUFAs Polyunsaturated fatty acids NPTII Neomycin phosphotransferase gene UIDA β-Glucuronidase gene PCR Polymerase chain reaction RT-PCR Real time polymerase chain reaction FAME Fatty acids methyl ester ROS Reactive oxygen species Introduction Tomatoes contain many health benefits as decreasing the risk of prostate cancer and cardiovascular diseases [ 1, 2]. Postharvest handling is an important research area in tomato crop in order to avoid postharvest losses and to enjoy its nu- tritional quality [3, 4]. Softening occurs during this period and has received attention because it influences consumer percep- tion and thus determines their postharvest life and economic value. Tomato texture and the genes encoding the enzymes related to softening have been the goal for genetic manipula- tions with the target of extending postharvest life [5]. A group of enzymes associated with membrane breakdown in tomato fruit are the lipoxygenases (LOX) [6, 7]. LOX catalyzes the * Miguel A. Gómez-Lim mgomez@ira.cinvestav.mx * Hugo Sergio García hugosgg@gmail.com 1 Unidad de Investigación y Desarrollo en Alimentos (UNIDA) del Instituto Tecnológico de Veracruz, Veracruz, Veracruz, Mexico 2 Centro de Investigación y de Estudios Avanzados del Instituto Politécnico Nacional (CINVESTAV) Irapuato, Guanajuato, Mexico Plant Foods Hum Nutr DOI 10.1007/s11130-017-0629-y