• Korean Journal of Plant Tissue Culture
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• v.26 no.3
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• pp.197-203
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• 1999

The albino plants of tobacco (Nicotiana tobacum L. cv. BY-4) were isolated from seed populations that were induced by heavy-ion ($^{14}N$) beam irradiation to proembryo and the in vitro growth and differentiation have been characterized. The in vitro cultured albino plants showed significant reduction of chlorophyll content and possessed larger number of stomata on both upper and lower epidermis than that of wild-type plants. Stem growth of the mutants remained dwarfed, however, the internode recovered its normal length after GA$_3$ treatment (10.0mg/L) on the MS medium containing sucrose under continuous light. When explants of leaf blades of albino plants were cultured, multiple shoots formed directly on MS medium containing 1.0mg/L of BAP or kinetin and a large number of calli were induced on the MS medium containing 1.0mg/L NAA or 1.0 mg/L 2,4-D. The albino calli regenerated multiple albino plantlets in the MS medium containing 0.1mg/L NAA + 1.0 mg/L BAP. No significant differences between the wild-type and albino plants were detected in the multiple shoot induction, callus formation from the explants and the plantlets regeneration from calli. In addition, albino plants have a similar organogenesis Pattern to that of the wild-type in the media with different combinations of NAA (0 to 5.0mg/L) and BAP (0 to 5.0mg/L) treatment. These results indicate that the albino mutant has the same normal regeneration ability as that of wild-type, although the mutant has lost functions in photosynthesis, such as pigmentation.

• Journal of Plant Biotechnology
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• v.1 no.2
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• pp.101-107
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• 1999

The leaf blade-segments of albino tobacco (Nicotiana tabacum L.) were cultured on MS media containing different concentrations of BAP (0, 0.4, 2.2, 4.4, 22.2 ${\mu}{\textrm}{m}$) with or without NAA (0, 0.5, 2.7 ${\mu}{\textrm}{m}$). Multiple shoots were induced on the media containing 0.4 to 2.2 ${\mu}{\textrm}{m}$ BAP. The best condition for multiple shoot induction with root formation was MS media containing 4.4 ${\mu}{\textrm}{m}$ BAP and 0.5 ${\mu}{\textrm}{m}$ NAA. The regenerated albino plants showed a significant reduction in accumulation of chlorophylls and carotenoids. The drastic reduction of the pigments content was associated with the distinct alterations in gene expression in the albino plants. firstly, the expression of plastid genes, such as rbcL, psbA, 165 rDNA and 235 rDNA, was reduced at the level of transcripts in the regenerated albino plants. Secondly, the alteration of structure of the plastid genes was not detected in the albino plants. However, the copy number of the plastid genes whose transcription level was reduced greatly was increased approximately two-fold, although the transcriptions of nuclear gene (255 rDNA) showed the wild-type level.