Enhancement of capsaicinoids in vitro production by abiotic elicitors in placenta-derived callus of Capsicum annuum L. Tunisian var. ‘Baklouti Medenine’

Abstract

Production of natural phytochemicals via tissue culture is an efficient method for both laboratory and industrial-scale production. To evaluate the influence of abiotic elicitation on in vitro production of capsaicinoids (CAPs), callogenesis was induced from the placenta of pepper (Capsicum annuum L.) Tunisian var. ‘Baklouti Medenine’ on MS medium supplemented with 9.04 μM 2,4-dichlorophenoxyacetic acid (2,4-D) and 2.32 μM kinetin (Kin). Placenta-derived callus was subjected to different concentrations of sucrose, sodium chloride (NaCl), polyethylene glycol (PEG 6000), and silver nitrate (AgNO3). After 4 wk. of culture, callus was harvested and capsaicin (C) and dihydrocapsaicin (DHC) were quantified by liquid chromatography-mass spectrometry (LC-MS). Maximum callus production was obtained with 34.22 mM and 68.44 mM NaCl, with an improvement in growth index (GI) by 3481% and 3736% respectively. In elicitation-free culture, DHC was the major CAPs (79.27%). The highest accumulation of DHC was obtained with 17.11 mM NaCl (39.52 mg g−1 DW; 4% of callus DW). Meanwhile, elicitation raised C content to approximately three times that of DHC. C production increased from 0.17 mg g−1 DW in control culture to 27.88 and 26.79 mg g−1 DW at 17.11 mM NaCl and 14.71 μM AgNO3, respectively. For both treatments, C represented more than 2.6% of callus DW. 17.11 mM NaCl-treated callus, which produced the highest concentrations of both C and DHC, showed the least callus production. Hence, Tunisian var. ‘Baklouti Medenine’ appears an interesting resource for these alkaloids biosynthesis and can be used to develop a large scale production of valuable CAPs compounds.