In: Phyton 58, Fasc. 2 (2018): S. 175-184 DOI: 10.12905/0380.phyton58(2)-2018-0175 Published online on 21st December 2018

Published online on 21st December 2018

Gene expression and adventitious root formation on auxin containing medium as influenced by cytokinin type during the multiplication stage in micropropagation of moringa

Ahmed M. Hassanein, Fayza A. Faheed, Jehan M. Salem & Abdullah A. El-nagish

Key words: Auxins, cytokinins, gene expression, antioxidant enzymes, rhizogenesis, micropropagation, moringa, Moringa oleifera

Summary
Hassanein A. M., Faheed F. A., Salem J. M. & El-Nagish A. A. 2018. Gene expression and adventitious root formation on auxin containing medium as influenced by cytokinin type during the multiplication stage in micropropagation of moringa. – Phyton (Horn, Austria) 58 (2): 175–184, with 8 figures and 6 tables.*


To study gene expression during root formation, cotyledonary nodal segments of aseptically germinated seedlings were used for induction of shoot formation on cytokinin containing medium followed by induction of root formation on auxin containing medium. Nodal segments free of cotyledons showed a low tendency to form shoots on basal MS medium. Shoot formation increased significantly when cotyledonary nodes with two complete cotyledons were used. Further increase in shoot formation and growth were detected when they were cultured on MS containing 0.56 mg/l of BAP. When the suitable concentration of IAA (0.5 mg/l), IBA (1.0 mg/l) and NAA (0.5 mg/l) for induction of root formation was determined, IAA was the best. Under the influence of IAA, roots were initiated directly on microshoot cuttings without enlargement or callus formation which facilitated acclimatization and the transfer of plants to open conditions. Quantitative determination of POX and CAT activities was in accordance with the isoenzyme pattern of both isoenzymes, with the darker staining isoenzyme forms being those with the higher activity under specific conditions. Root formation and expression of antioxidant enzymes (SOD, POX and CAT) on IAA containing medium were influenced by cytokinin type during the shoot formation stage. They were higher when 0.56 mg/l BAP was used for shoot multiplication and followed by 0.5 mg/l IAA for root formation as compared to the use of 0.56 mg/l KIN followed by 0.5 mg/l IAA. In addition, polypeptides specific for each cytokinin type were detected when shoots were subcultured on auxin containing medium for root formation.