A healthy lifestyle includes fruits and vegetables consumption. Tomato is one of the most consumed vegetables, 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 cauliflower 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 conditions, whereas wild type fruits remained in similar conditions for only six days. Firmness in pink and red stages was significantly 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.

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Lipoxygenase (LOX) enzyme activity and their putative isoforms were investigated during postharvest life in chayote fruit (Sechium edule Jacq. Sw. cv. “virens levis”). Possible associations of LOX with fruit quality parameters are discussed. Five LOX isoforms were identified (SeLOX‐1 to −5) displaying different activity patterns during ripening and senescence as well as in roots, stems, and leaves. The probable role of SeLOX‐5 as a specific isoform linked to senescence was examined. The highest relative activity of LOX was registered in fruit tissue, followed by leaves, stem, and roots. Correlations were found between LOX and fruit composition variables such as the contents of linoleic (LA) and linolenic (LNA) acids, weight loss, CO2 and ethylene production rates. LOX activity, and LA and LNA concentration decreased from Day 1 to Days 13–17, when early seed germination events became visible, indicating a transition stage between late fruit ripening and early senescence characterized by a deteriorative process. Practical applications Detrimental effects on fruit composition variables such as dehydration, weight loss, wilting, and sprouting symptoms, have been reported as the main causes that reduce the commercial quality and shelf life in chayote fruit and prevent their export to distant markets. To the best of our knowledge, the association of lipoxygenase (LOX) enzymes to non‐climacteric fruit ripening—like chayote—or their loss of commercial quality during prolonged shelf life has not yet been described. This is the first study that explores the role of chayote LOX activity in fruit, identifies various specific LOX isoforms associated to ripening or to the senescence process and provides new evidence that supports the hypothesis that putative LOX isoforms might be related to several postharvest detrimental effects on chayote fruit. This information could be useful to food processors or packers to pursue better profitability and consumer satisfaction.

-The presence of the Molytinae Heilipus lauri Boheman is reported for the fi rst time attacking fruits of Persea schiedeana, commonly called "chinene" in Huatusco and Zongolica, state of Veracruz, Mexico.KEY WORDS: Chinene, avocado weevil, spermophagous, mesoamerican fruit RESUMEN -Se reporta por primera vez la presencia del Molytinae Heilipus lauri Boheman atacando frutos de Persea schiedeana, comúnmente conocidos como "chinene" in Hustusco y Zongolica, Veracruz, México. PALABRAS-CLAVE: Chinene, picudo del aguacate, espermatófago, frutal mesoamericanoHeilipus lauri Boheman, el barrenador grande de la semilla del aguacate, Persea americana, es una plaga monófaga endémica de México y su único hospedero conocido es el aguacate. Este insecto se relaciona taxonómicamente con H. pittieri Barber y H. trifasciatus Fabricius, ambas especies documentadas en Costa Rica y Panamá como barrenadores de frutos de aguacate (Barber 1919, Dietz & Barber 1920, O'Brien & Wibmer 1982. La presencia de H. lauri en México se ha detectado en los estados de Hidalgo, Guerrero, Morelos, Puebla y Veracruz (Peña 1998). El principal daño lo causan las larvas al alimentarse de las semillas de los frutos en crecimiento, causando su caída prematura o el fruto puede permanecer en el árbol hasta que la larva alcanza su completo desarrollo (Peña 1998, Wysoki et al 2002.Peña (1998), documentó que H. lauri puede causar 80% de daño en la cosecha total de los frutos. En México, este insecto es de importancia cuarentenaria. Por lo tanto, existen restricciones para la movilización de frutos de aguacate a regiones libres de H. lauri y a mercados internacionales como el de los EE.UU., donde la plaga ha sido una barrera importante para la exportación (Leos-Rodríguez et al 2005).El fruto de P. schiedeana, conocido como chinene, es ampliamente consumido en la región central del estado 57' LO y 1300 ± 100 m sobre el nivel del mar) varios frutos de P. schiedeana dañados con larvas en su interior. Los frutos afectados se reconocieron fácilmente por un escurrimiento blanquecino. A las larvas se les permitió completar su desarrollo para determinar la especie de barrenador asociado. En los muestreos también se colectaron adultos del barrenador grande de la semilla del aguacate dañando directamente los frutos. Los especímenes capturados se montaron en alfi leres entomológicos para su conservación y posterior identifi cación. Para la identifi cación de la especie se empleó la clave propuesta por Barber (1919), y se enviaron dos especímenes adultos al Dr. Juan José Morón Ríos del Instituto de Ecología A. C. en la ciudad de Xalapa, Veracruz, para confi rmar la especie. Los resultados concuerdan que el barrenador de la semilla del chinene correspondió a la especie H. lauri.El macho adulto de H. lauri midió (excluyendo el rostro) 12.50 -15.15 mm y las hembras 13.03 -15.91 mm. En las hembras el rostro es largo y curveado (6.02 -8.38 mm); en 872 Castañeda-Vildózola et al -Persea schiedeana (Lauraceae), Nuevo Hospedero de Heilipus lauri Boheman... los machos es cor...

In terms of color, firmness, respiration, and ethylene production during the postharvest period, ripening is here characterized for the first time in the fruit of Persea schiedeana Nees. The results show a respiratory peak (respiratory climacteric) and an ethylene production peak, indicating that the fruit of P. schiedeana can be classified as climacteric. The fruit ripened rapidly, and senescence effects appeared 5 days after harvest. Together with appreciable weight loss during the postharvest period, this makes the fruit very perishable. Preliminary values for quantitative ripening indices are provided (fruit firmness, color lightness, hue angle, and chroma).

The objective of this study was to evaluate the influence of a new species of plant (Spathiphyllum blandum) in the elimination of chemical oxygen demand (COD), nitrogen, phosphorus and fecal coliforms (FCs) in mesocosms of wetlands with polyethylene terephthalate (PET) and tezontle substrates under a tropical climate. The experiments were developed at the mesocosm level in 20 experimental units; 10 were planted with Spathiphyllum blandum, five in PET substrates and five in tezontle, and 10 more were used as controls without vegetation, of which five contained tezontle and five contained PET. The systems were fed with contaminated water from the river Sordo, with a hydraulic retention time of 3 days for 12 months; samples were taken in the influent and effluents of the mesocosms every 2 weeks, with the purpose of evaluating the removal of contaminants. The results showed that presence of this species tended to improve or significantly improved the removal of COD, NH4-N, PO4-P, and FCs by 7%, 16%, 29% and 12%, respectively. It was also possible to confirm that the presence of this species reduced the rate of denitrification. These results confirm that in developing countries it is feasible to find new wetland species to be used for wastewater phytoremediation.

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