Biomass and polyphenolic enhancement in date palm (Phoenix dactylifera L.) callus cultures through Fusarium oxysporum elicitation

Phoenix dactylifera L. known as date palm is a precious horticultural cash crop for arid and semi-arid regions, and an important medicinal plant rich in bioactive compounds (phenolics, flavonoids, antioxidants). Tissue culture remains an eco-friendly biotechnological technique to provide quality-planting propagules and sustainable synthesis of phytochemicals and plant biomass using elicitation as a highly efficacious strategy approach. In this framework, various concentrations (25, 50, 100, 200, and 400 mg/L) of Fusarium oxysporum Schlecht. as a biotic elicitor in callus cultures of P. dactylifera were tested. Results revealed that callus biomass yield, total phenolic content (TPC), total flavonoid content (TFC), and bioactive compound levels were found significantly elevated under the effect of fungal elicitation, irrespective of concentration as compared with the non-elicited control treatment. The findings demonstrated that the optimum fresh weight (FW) (1215.8 mg), dry weight (DW) (628.3 mg), TPC [209.6 mg gallic acid equivalents (GAE)/100 g DW), total phenolic production (131712.6 mg/L), TFC (96.2 mg quercetin equivalent (QE)/100 g DW), total flavonoid production (60463.4 mg/L), accumulation of apigenin (32.1 mg/g), caffeic acid (25.8 mg/g) and catechin (24.1 mg/g DW) as phenolic compounds as well as kaempferol (16.9 mg/g), quercetin (15.6 mg/g) and rutin (14.8 mg/g DW) as flavonoid compounds, were achieved when date palm callus cultures were incubated with 50 mg/L F. oxysporum as an elicitor for 30 days. The outcomes of this study could be of great usefulness in the nutraceutical and agronomic industries, facilitating the further development of large-scale production of polyphenols and the utilization of bioreactors. Key message Fusarium oxysporum at 50 mg/L-an effective biotic elicitation approach for fresh/dry biomass growth, total phenolic/flavonoid production, apigenin, caffeic acid, catechin, kaempferol, quercetin and rutin accumulation in date palm callus cultures.