A b-xylosidase gene could act as good indicator of tolerance to chilling injury in peach fruit

BUSTAMANTE, C.; GENERO, M.; GISMONDI, M.; MONTI, L.; GABILONDO, J.; BUDDE, C.; LARA, M.V.; DRINCOVICH, M.F.

Rosario

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

The storage of peaches at low temperatures for prolonged periods can induce a form of chilling injury (CI) called woolliness, characterized by a lack of juiciness and a mealy texture. As this disorder has been associated with abnormal cell wall dismantling, resistant (Springlady), intermediate (Rojo 2) and susceptible (Flordaking) cultivars were selected to study the levels of twelve transcripts encoding proteins involved in cell wall metabolism. Of all cell wall-related genes studied, only PpXyl, which encodes for a putative β-xylosidase, seems to act as good indicator of tolerance to CI, as its expression correlated with the different susceptibility to this disorder after cold storage. PpXyl full-length was cloned and sequenced in the three cultivars in order to look for changes in PpXyl that may alter the capacity of function of the protein. In addition, a fragment of 1637 bp, corresponding to the promoter region of the gene, was isolated from Springlady, Rojo 2 and Flordaking genomic DNA in order to investigate the presence of putative regulatory sequences that may be responsible for the differential patterns of expression. The presence of cis-acting elements associated with hormone and stress-related responses, along with the results obtained in this work, suggest a role of PpXyl in determining different tolerance to CI in peach fruits.