A ripening specific bZIP gene of peach was studied by ectopically expressing it in tomato. Two lines, witheither a mild or a strong phenotype, respectively, were analyzed in detail. Transgenic fruit morphologywas normal, yet the time spent to proceed through the various ripening stages was longer compared towild type. In agreement with this finding the transgenic berries produced less ethylene, and also had amodified expression of some ripening-related genes that was particularly evident in berries with a strongphenotype. In particular, in the latter fruits polygalacturonase and lipoxygenase genes, but also genescoding for transcription factors (TFs) important for tomato ripening (i.e. TAGL1, CNR, APETALA2a, NOR) didnot show the expected decreased expression in the red berries. As regards the RIN gene, its expressioncontinued to increase in both mild and strong lines, and this is in agreement with the dilated ripeningtimes. Interestingly, a metabolomic analysis of berries at various stages of ripening showed that thelonger time spent by the transgenic berries to proceed from a stage to another was not due to a slackenedmetabolism. In fact, the differences in amount of stage-specific marker metabolites indicated that thetransgenic berries had a very active metabolism. Therefore, the dilated ripening and the enhancedmetabolism of the berries over-expressing the bZIP gene suggest that such gene might regulate ripeningby acting as a pacemaker for some of the ripening metabolic pathways.
File in questo prodotto:
Non ci sono file associati a questo prodotto.