<em>In vitro</em> adventitious plant regeneration of <em>Echium orientale</em> L., an endemic plant: The evaluation of biological activities and phenolic content

Abstract

<em>Echium orientale</em> L. is a Turkish endemic plant in the family Boraginaceae. The aim of this study was to develop an efficient <em>in vitro</em> culture protocol for <em>E. orientale</em> and compare the field-grown and <em>in vitro</em>-grown leaves in terms of antibacterial, antitumor and antioxidant activities and phenolic profiles. Leaf and petiole explants were cultured on Murashige & Skoog (MS) medium with various plant growth regulator combinations. Best shoot proliferation was obtained from leaf explant with 1 mg/L thidiazuron (TDZ) and 0.5 mg/L indole-3-acetic acid (IAA), producing 8.7 shoots per explant at 100% shoot frequency. Regenerated shoots were transferred to rooting media containing different levels of IAA, indole-3-butyric acid (IBA), naphthalene acetic acid (NAA) or 2,4 dichlorophenoxyacetic acid (2,4-D). The best root formation was observed with MS basal medium (control). Rooted explants were transferred to vermiculate in Magenta containers for acclimatization and after 3 weeks they were transferred to plastic pots containing potting soil and maintained in the plant growth room. Leaves from field-grown plants showed higher antibacterial, antitumor and antioxidant activities, and phenolic content than those from <em>in vitro</em>-grown plants.