Analysis of the raffinose family of oligosaccharides (RFO) pathway in peach exposed to cold stress

MONTI, L.; BUSTAMANTE, C.; GABILONDO, J.; VALENTINI, G.; BUDDE, C.; FERNIE, A.; LARA, M.V.; DRINCOVICH, M.F.

Rosario

Congreso; L Reunión de la Sociedad Argentina de Investigación en Bioquímica y Biología Molecular; 2014

Peaches deteriorate quickly at ambient temperature. Cold storage is commonly used to prevent fruit decay; however, it affects fruit quality causing physiological disorders collectively termed ?chilling injury? (CI). In previous studies, relative levels of transcripts encoding enzymes involved in galactinol and raffinose metabolism were studied by qRT-PCR to explain the increase observed in these two metabolites after refrigeration of six different peach cultivars. Results obtained indicated that the transcript levels of PpGolS (galactinol synthase) and PpRS (raffinose synthase), increased dramatically after refrigeration in comparison to fruits of the same post-harvest age kept at 20 °C, although the level of increase was different between them. In the present work, to extend the study of this pathway, transcript levels of genes encoding two α-galactosydases (PpSIP1 and PpSIP2), involved in the hydrolysis of raffinose, were analyzed in the six varieties after cold treatment of fruits. Once again, a variety-dependent increase was found after refrigeration. Furthermore, full-length cDNAs of PpGolS and PpRS were analyzed in the six varieties and no differences were found. We propose that RFO pathway is transcriptionally regulated and that the particular pattern of expression observed in each variety could reflect different strategies to cope with chilling stress in this fruit.