Plant Regeneration from Protoplasts and Cell Cultures of Nicotiana tabacum Sulfur Mutant (Su/Su)

Abstract

The sulfur locus of Nicotiana tabacum segregates in a 1:2:1 ratio for green (su/su) : yellow-green (Su/su) : albino (Su/Su).Shoot cultures were initiated from leaf tissue of the albino on MS-agar with 1 μM benzyladenine and subcultured on the same medium. Cell suspension cultures were established from callus of leaf tissue of the albino (Su/Su) mutant.Plant regeneration was easily achieved from cell cultures on MS-agar medium with 1 or 5 uM benzyladenine.The chromosome number of the cell culture has remained diploid 2n=48 and the plant regenerating capacity has persisted for more than two years.Protoplasts were isolated routinely from the cells and cultured.The protoplast-derived cells regenerated plants at a high frequency.Although the plants formed roots, they were unable to survive in pots in the absence of sugar.The shoots were propagated on MS-agar with 1 μM benzyladenine.Root development occurred in the MS-agar without hormones, but bolting and flower formation was not observed. Isoenzyme analyses of 8 enzymes were performed on materials of the green, yellowgreen and albino plants as well as the albino cell culture.There were characteristic variations in most of the zymograms of the different tissue extracts.Ultrastructural examinations revealed the presence of two types of plastids in the albino leaf material based on variations in internal structures.