Plant regeneration from Ri T-DNA transformed roots of cabbage.

Ri T-DNA transformed roots were induced out on hypocotyl segments of cabbage infected with Agrobacterium rhizogenes. After cultured for four months on solid MS medium without hormones, some parts of a few of transformed roots were dedifferentiated into callus clumps, and then redifferentiated into shoot buds. On solid MS medium supplemented with kinetin, shoot buds were differentiated directly from transformed roots without callus formation. Among several concentrations of kinetin, 14 microM gave rise to the best results for differentiation of shoot buds. In liquid MS medium, 4.5 microM of 6-benzylaminopurine (BA) also showed the increase in the number of shoot buds from transformed roots. All of these shoot buds were able to grow further, root out on root induction medium, and develop into young plants.