Ascorbic acid and polyphenols accumulation in callus culture of tomato introgression lines

Antioxidants such as ascorbic acid (AsA) and polyphenols (Phe) have often been studied for their cancer-preventive and immune system empowering activity. Plant production of such antioxidant metabolites is quite low and not constant during time in vivo condition. Therefore, our aim is to assess the production of AsA and Phe in vitro culture and to analyse how their content varies during callus growth in tomato callus culture. In particularly, we have focused our attention on leaf and petiole explants of three introgression lines (IL7-3, IL10-1 and IL12-4) of Solanum pennellii into S. lycopersicum cv. M82 background expressing QTLs for fruit AsA concentration. Callus cultures were successfully obtained from plants growth in vitro and frequencies of callus and antioxidants content were scored at 0, 15, 30, 45 and 60 days of in vitro culture. Callus induction and proliferation were explants and genotype dependent. Higher percentage of callus was observed in petiole explants at early stages of growing. At stationary phase of callus growth the Phe content was found to be higher than the first stages in all genotypes and explants assayed. On the contrary, total AsA accumulation decreased during callus growth. The data obtained from this study suggest the possibility to produce stably Phe and AsA in vitro callus cultures rather than field-grown plant tissues of tomato. Furthermore, efforts will focus on elucidating genetic mechanisms that controls antioxidant accumulation in undifferentiated tissue through transcriptomic approach.