Roses have been one of the top ten cut flowers in the world What many studies have focused on their high-quality after harvest. Ethylene accelerated senescence in sensitive cut flowers and it seems that gibberellin prolongs their longevity by neutralizing the activity of abscisic acid. Therefore, in this work, ethylene-insensitive cut roses containing etr1-1 gene were evaluated.
Cut roses prepared from an isolated greenhouse at commercial stage, after transferring to the laboratory, were treated by GA3 (0, 40 and 80 mg l-1) and then the content of some secondary metabolites assessed. Evaluations were carried out in control and transgenic lines in the bud and half-open stages. The research was performed in completely randomized factorial design by four replicates. After measuring and applying the statistical differences at the P 0.05 level via SAS software was done. The results showed that gibberellin significantly increased chlorophyll a, b and carotenoid contents in the bud and half-open stages in control and transgenic lines. Maximum pigment content was observed in transgenic line in the bud and half-open stages treated by 80 mg l-1 gibberellin which had a significant difference in comparison with the same stages in the control line. Also, anthocyanin and flavonoid contents decreased in control and transgenic lines with higher concentrations of gibberellin in all developmental stages, it seems that gibberellin by reducing senescence oxidative damage could be prolonged the vase life. The minimum amount of these compounds was observed in the bud and half-open stages in transgenic line by 80 mg l-1 gibberellin which had a significant difference in comparison with the same stages in the control line. Therefore, genetic manipulation of ethylene receptor genes of ethylene-sensitive flowers as well as roses accompanied by gibberellin treatment could be considerably improved longevity.