Cell wall metabolism in ‘Dixiland’ peaches after harvest and heat treatment

BUSTAMANTE, CLAUDIA; LAUXMANN, MARTÍN ALEXANDER; BORSANI, JULIA; LOMBARDO, VERONICA; BUDDE, CLAUDIO OLAF; MURRAY, RICARDO; ANDREO, CARLOS SANTIAGO; LARA, MARÍA VALERIA; DRINCOVICH, MARÍA FABIANA

Tucumán. Argentina

Congreso; XLV Reunión de la Sociedad Argentina de Investigación en Bioquímica y Biología Molecular (SAIB); 2009

SAIB

Refrigeration of peaches during marketing and shipping affects fruit quality causing physiological disorders collectively named chilling injury (CI). In order to alleviate CI, different strategies have been applied before cold storage, among them heat treatment (HT) have been widely used. In this work, we analyzed the ethylene production, fruit firmness and the expression of enzymes and proteins involved in cell wall metabolism in peaches immediately after harvest (C), when they have been kept at 20 ºC for 3, 5 and 7 d (C+3, C+5 and C+7), or when they were exposed to 39 ºC for 3 d (TT) followed by 3 d at 20 ºC (TT+3). For the group of fruit kept at 20 ºC, it was observed a typical softening behaviour as well as an increase in ethylene production until C+3. In contrast, during the 3 d of HT, fruit maintained their firmness, which rapidly decrease after transfer to 20 ºC. Relative expression of genes was determined by performing quantitative real-time PCR using sets of specific primers based on previous reports. Cell wall-related genes showed different expression levels during peach ripening. However, TT decreased markedly the accumulation of mRNA from all of them. Once TT fruits were transferred to 20 ºC, an increase in gene expression occurred to different extent. This study will help in the identification of varieties more resistant to CI and in the development of new technologies.