α-L-Arabinofuranosidase activity during development and ripening of normal and ACC synthase antisense tomato fruit

• Autores: Sozzi, Gabriel Oscar; Fraschina, Adela Ana; Navarro, Agustín A.; Cascone, Osvaldo; Greve, L. Carl; Labavitch, John M.
• Año de publicación: 2002
• Idioma: inglés
• Tipo de recurso: artículo
• Materia: ETHYLENE; GLYCOSIDASE; LYCOPERSICON ESCULENTUM
• Institución: Consejo Nacional de Investigaciones Científicas y Técnicas

α-L-Arabinofuranosidases (α-Af) are plant enzymes that have the capacity to release terminal arabinofuranosyl residues from a wide variety of pectic and hemicellulosic polymers, as well as different glycoconjugates. Our interest in α-Af is related to its potential role in ripening-related loss of arabinose from tomato fruit cell walls. Using both control (cv. VF 36) and ACC synthase antisense (A11.1) tomatoes (Lycopersicon esculentum Mill.), we demonstrate that tomato α-Af activity is present during the entire ontogeny of the fruit. Immature 10-day-old fruit displayed 6-fold more α-Af activity on a per gram fresh weight basis, than mature green fruit. In VF 36 fruit, α-Af activity increased 45% from mature green 4 (48 days post anthesis) to light red stages (55 days) when fruit ripened on the vine. In contrast, no similar increase was detected in ACC synthase antisense fruit that do not ripen in the same time frame. However, when A11.1 fruit were detached at 48 days after anthesis and treated continuously with 100 mL·L-1 ethylene the fruit ripened and α-Af increased, as in ripening normal fruit. The α-Af activity pattern is similar to that reported for tomato β-galactosidases. The increasing α-Af activity during ripening and the decreased activity in antisense ACC synthase fruit after reaching the mature green stage suggest a role for ethylene in the ripening-related synthesis or activation of this enzyme.
Fil: Sozzi, Gabriel Oscar. Universidad de Buenos Aires. Facultad de Agronomía. Departamento de Biología Aplicada y Alimentos; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay; Argentina
Fil: Fraschina, Adela Ana. Universidad de Buenos Aires; Argentina
Fil: Navarro, Agustín A.. Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica. Departamento de Microbiología, Inmunología y Biotecnología; Argentina
Fil: Cascone, Osvaldo. Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica. Departamento de Microbiología, Inmunología y Biotecnología; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay; Argentina
Fil: Greve, L. Carl. University of California; Estados Unidos
Fil: Labavitch, John M.. University of California; Estados Unidos