Ripening-related ethylene responsive factor characterization by Agrobacterium-mediated stable gene transfer in grapevine

Knowledge of the regulatory circuits and of the transcription factors involved in ripening in grape is lacking. There is evidence of ethylene playing a role in fruit ripening and we have recently identified four ethylene responsive factor (ERF) genes which are transcriptionally modulated at the véraison phase. Their gene expression profiles suggest an involvement in ripening regulation. In order to understand the function of the VvERF1 gene in grape, its over-expression and silencing were carried out by gene transfer technology in Vitis vinifera ‘Brachetto’. The complete VvERF1 coding sequence was cloned in pK7WG2 vector for over-expression, whereas a 209 bp VvERF1 specific sequence was cloned in pK7GWIWG2 (II) for gene silencing. We regenerated 20 plants putatively over-expressing VvERF1 and 5 plants putatively silencing VvERF1. According to molecular analysis, five of them contained the exogene VvERF1 gene under 35S promoter control. Further characterization is in progress in the view of assessing the over expression of this exogene