Sumac (Rhus coriaria L.) sprouts: from in vitro seed germination to phenolic content and antioxidant activity for biotechnological application

The sumac plant (Rhus coriaria L.), native to the Middle East, but also growing in Italy, is used for the medicinal properties of its fruits and leaves. Recently, sumac plant have been characterized in terms of their bioactive compound content and biological activity. Regrettably, there is a lack of information on the chemical composition of sumac sprouts, which, on the contrary, could be a rich source of interesting compounds, as demonstrated for other plant species. To make the production of sumac sprouts faster and independent of environmental conditions, in vitro tissue culture can be an efficient solution. This study first established a valid protocol for in vitro sumac seed germination; secondly, the obtained sprouts were characterized, in terms of phenolic content and antioxidant activity. The results showed that mechanical scarification is mandatory to trigger in vitro germination of sumac seeds. Moreover, a significant final germination percentage and a reasonable mean germination time was obtained combining scarification, cold stratification and gibberellic acid-enriched culture media. Chemical characterization of sumac sprouts has shown that they are a source of potentially bioactive compounds, as they are rich in polyphenols and have appreciable antioxidant activity.