Regeneration of shoots from Brassica juncea (Linn) czern and coss cells transformed by Agrobacterium tumefaciens and expression of nopaline dehydrogenase genes

Abstract

Tumours formed on Brassica juncea plants inoculated with Agrobacterium tumefaciens strain A 208 having plasmid pTiT37 were cultured in vitro. Bacteria-free cultures were obtained after 3–4 passages on basal medium containing streptomycin. Axenix cultures of tumour tissue grew on basal medium without growth hormones. Spontaneous regeneration of shoots from the cultured tumour tissue was observed occasionally. The regenerated shoots did not produce roots even after culturing them on media containing root-promoting hormones. The leaf explants from the regenerants when cultured on hormone-free media formed callus at the base and at the sites of injury on the lamina. Axenix tumour tissue showed the presence of nopaline and nopaline dehydrogenase activity. The regenerated shoots and leaves were nopaline positive.