TY - JOUR ID - 7089 TI - Regeneration of Glyphosate-Tolerant Nicotiana tabacum after Plastid Transformation with a Mutated Variant of Bacterial aroA gene JO - Iranian Journal of Biotechnology JA - IJB LA - en SN - 1728-3043 AU - Fathi Roudsari, Mehrnoosh AU - Salmanian, Ali Hatef AU - Mousavi, Amir AU - Hashemi Sohi, Haleh AU - Jafari, Mahyat AD - Department of Plant Biotechnology, National Institute of Genetic Engineering and Biotechnology (NIGEB), P.O. Box 14965/161, Tehran, I.R. Iran and Khatam Institute of Higher Education, Tehran, I.R. Iran AD - Department of Plant Biotechnology, National Institute of Genetic Engineering and Biotechnology (NIGEB), P.O. Box 14965/161, Tehran, I.R. Iran Y1 - 2009 PY - 2009 VL - 7 IS - 4 SP - 247 EP - 253 KW - Plastid transformation KW - Nicotiana tabacum KW - Glyphosate KW - 5-enoylpyruvyl shikimate-3-phosphate synthase DO - N2 - Presence of antibiotic resistance markers has always been considered as one of the main safety concerns in transgenic plants and their derived products. Elimination of antibiotic selectable markers from transgenics is a major hurdle for finding efficient and safe candidates. Herbicide tolerance genes might be attractive alternatives. In this study, a variant form of the 5-enoylpyruvyl shikimate-3-phosphate synthase (EPSPS) gene that harbors glycine at position 96 to alanine and alanine 183 to threonine substitutions and confers higher resistance to the broad-spectrum herbicide, glyphosate, was substituted against the spectinomycin resistant gene as a sole selectable marker for plastid transformation of Nicotiana tabacum. Plastid transformation was carried out using the biolistic delivery procedure while delivery parameters such as rupture disk pressure, bombardment distance, etc had been optimized first. A previous study showed that the glyphosate herbicide imposes lethal effects on the structure and integrity of the plastid membrane, even at low concentrations. In order to overcome this problem, a modified procedure for selection of transplastomic cells was used. A long preculture incubation period followed by a gradual increased in glyphosate concentration led to sufficient expression of the transgene. Tolerant calli were thus regenerated through direct selection of transformed plastids in the presence of the glyphosate. UR - https://www.ijbiotech.com/article_7089.html L1 - https://www.ijbiotech.com/article_7089_cd78b993e56aad0e1401f7cd73bd11d8.pdf ER -