Postharvest chilling induces oxidative stress response in the dwarf tomato cultivar Micro‐Tom

Abstract

Oxidative stress is involved in the response of Lycopersicon esculentum fruits (cultivar Micro‐Tom) to chilling. Changes in activated oxygen scavenging enzymes, superoxide dismutase (SOD, EC 1.15.1.1), catalase (CAT, EC 1.11.1.6), ascorbate peroxidase (APX, EC 1.11.1.11), and glutathione reductase (GR, EC 1.6.4.2) were examined during ripening after postharvest chilling. Also, lipid peroxidation, respiration, and pigment contents were determined. These parameters were affected by chilling, especially the lycopene content and the respiration rate that showed a high value when the fruits were transferred to higher temperatures. CAT activity increased the day after the fruits were re‐warmed, while the activity of GR was higher in the chilled than in the non‐chilled green fruits. Lipid peroxidation was more evident at the ‘pre‐chilled’ yellow and red fruits. APX and SOD were not affected by previous chilling in ripening fruits. These results indicate that oxidative stress is generated by conservation at 4°C. The antioxidant response of tomato fruit could be mediated by CAT and GR but not by SOD or APX. Moreover, CAT seemed to respond to the increase in the respiration rate.

Physiological, hormonal and molecular mechanisms regulating chilling injury in horticultural species. Postharvest technologies applied to reduce its impact

“…Of the other antioxidant enzyme activities analysed, SOD, APX and GR, only the latter showed an increase in activity, but it was not as high or sustained and, unlike that of CAT, took place during the period of storage at 4 • C. 79 In a study of low-temperature storage of CI-tolerant and sensitive mandarin varieties, Sala 74 observed a similar increase in SOD activity in both groups, but the tolerant varieties showed higher activities of CAT, APX and GR. In an experiment carried out using genetically modified Charentais cantaloupe melon with inhibited autocatalytic ethylene production, the emergence of CI resistance was observed in comparison with untransformed fruit.…”

“…• C. 79 Another way of reducing ROS levels in plants is the prevention of their formation. This can be achieved by the activation of a group of enzymes called alternative oxidases (AOXs).…”

Qualidade do tomate ‘PITENZA’ com utilização da radiação ultravioleta (UV-C)

“…Comportamento inverso ao descrito por Malacrida et al (2006), que relataram a diminuição no acúmulo de licopeno durante o amadurecimento normal de tomates 'Micro-Tom'. Nesse contexto fica claro a ação da radiação UV-C na manutenção da síntese de licopeno, observando que todos os frutos submetidos a radiação apresentaram concentrações mais elevados em comparação aos frutos controle.…”

Magnetic resonance imaging provides spatial resolution of Chilling Injury in Micro-Tom tomato (Solanum lycopersicum L.) fruit

“…Its high-density growth, short life cycle and concentrated fruit-set (i.e., many fruit of a similar age) makes it possible to obtain harvests of 500 fruit or more per square meter per year (Meissner et al, 1997). Because tomato postharvest studies can be hampered by biological variability (Hertog et al, 2004), the availability of numerous, similarly aged fruit makes Micro-Tom a convenient experimental model for postharvest studies (Gomez et al, 2009;Luengwilai et al, 2012a,b;Malacrida et al, 2006;Re et al, 2012;Sorrequieta et al, 2013;VegaGarcia et al, 2010;Weiss and Egea-Cortines, 2009). Furthermore, we have previously characterized Micro-Tom fruit physiological response to a range of postharvest chilling temperature-time combinations (Luengwilai et al, 2012a), and used this information to design a metabolomics investigation of CI (Luengwilai et al, 2012b).…”