Vol. 82 No: 1

Title:
Expression of anti-oxidant enzyme genes in scald-resistant 'Belfort' and scald-susceptible 'Granny Smith' apples during cold storage

Authors:
P. ZUBINI, E. BARALDI, A. DE SANTIS, P. BERTOLINII and M. MARI

pp: 149-155

Abstract:
Real-Time PCR was used to determine whether the levels of mRNAs coding for anti-oxidant enzymes varied in apple peel during post-harvest cold storage, and if these were correlated with the occurrence of apple scald symptoms. Levels of the scald-related compounds, α-farnesene and conjugated trienes (CT; particularly, CT281 and CT258), were determined in fruit peel of the scald-resistant apple ´Belfort` and the scald-susceptible apple ´Granny Smith` during storage. α-Farnesene levels varied, irrespective of the incidence of scald, whereas the levels of CTs were correlated with the degree of scald. On the other hand, the level of H₂O₂ in ´Granny Smith` apple peel increased gradually, but significantly, from harvest during storage, whereas this value did not vary in ´Belfort` peel. In both apple cultivars, the levels of mRNA for Mn superoxide dismutase (MnSOD) decreased with storage time, whereas the levels of ascorbate peroxidase (APX) mRNA did not vary. In ´Granny Smith` apples, mRNA levels for catalase (CAT) increased dramatically (7.8-fold) late in the storage period. Monodehydro-ascorbate reductase (MDHAR) and glutathione reductase (GR) mRNA levels also increased greatly (12- and 18.8-fold, respectively) early in storage. Conversely, in ´Belfort` apples the transcript levels of these genes did not change during storage. These results indicate that scaldresistance in ´Belfort` apples was not directly related to higher levels of mRNAs for anti-oxidant enzymes. However, the higher levels of H<sub>2</sub>O<sub>2</sub> in ´Granny Smith`apples was positively correlated with the higher levels of mRNAs for the anti-oxidant enzymes CAT, GR and MDHAR, suggesting direct regulation by the level of H₂O₂ on transcription of these anti-oxidant enzyme genes.

Full text: JHSB Subscribers     ISHS members & other users
(PDF 194876 bytes)

Go back to previous page