Esterase and peroxidase isoforms in different stages of morphogenesis in Fritillaria meleagris L. in bulb-scale culture

Morphogenesis in vitro is a complex and still poorly defined process. We investigated esterase and peroxidase isoforms detected in bulb scale, during Fritillaria meleagris morphogenesis. Bulbs were grown either at 4 degrees C or on a medium with an increased concentration of sucrose (4.5%) for 30 days. After these pre-treatments, the bulb scales were further grown on nutrient media that contained different concentrations of 2,4-dichlorophenoxyacetic acid (2,4-D) and kinetin (KIN) or thidiazuron (TDZ). Regeneration of somatic embryos and bulblets occurred at the same explant. The highest numbers of somatic embryos and bulblets were regenerated on the medium containing 2,4-D and KIN (1 mg/L each), while morphogenesis was most successful at a TDZ concentration between 0.5 and 1 mg/L. Monitoring of esterases and peroxidases was performed by growing bulb scales on a medium enriched with 2,4-D and KIN or TDZ (1 mg/L), and the number and activity of isoforms were followed every 7 days for 4 weeks. In control explants, six isoforms of esterase were observed. Three isoforms of peroxidase were not detected in the control bulb scale, which has not begun its morphogenesis process. 2015 Academie des sciences. (C) Published by Elsevier Masson SAS. All rights reserved