Genetic transformation of apple pulp calli as a possible strategy for the production of bioactive compounds

The manipulation of biosynthetic routes is a plant research sector in continuous expansion to meet the worldwide growing demand of health promoting compounds (1). To set up a means for a standardized production of anthocyanins, here we aimed at developing a genetic transformation system to introduce in apple pulp calli the maize helix-loop-helix (bHLH) transcription factor Sn and a marker for kanamycin resistance. Apple pulp calli are in fact competent to acquire a red colour only under continuous light treatment (2). Conversely, when ectopically expressed, Sn gene can boost the accumulation of anthocyanins in different species and under different enviromental conditions (3). To optimize the culture/selection system, apple pulp calli were grown on different kanamycin concentrations and 300mg/L was selected as the optimal one. Meantime, in order to gain a glimpse on the protein profile in this material, we carried out a SDS-PAGE analysis of the total proteins extracted from white (in the dark) and red (in the light) apple pulp calli. Several red calli - specific proteins have been identified and they will be sequenced in the next future. Apple pulp calli transformation with Sn via Agrobacterium tumefaciens is ongoing. 1-Dias Mi- ?2016. Exploring plant tissue culture to improve the production of phenolic compounds: A review 2-Verardo G, Gorassini A, Ricci D and Fraternale D (2016). High Triterpenic Acids Production in Callus Cultures from Fruit Pulp of Two Apple Varieties. Phytochemical Analysis, DOI 10.1002/pca.2638 3-Robbins MP, Paolocci F, Hughes JW, Turchetti V, Allison G, Arcioni S, Morris P, Damiani F. (2003). Sn, a maize bHLH gene, modulates anthocyanin and condensed tannin pathways in Lotus corniculatus. Journal of Experimental Botany, DOI: 10.1093/jxb/erg022