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Some accounts of nicotine biosynthesis in tobacco callus tissues by the use of effective and ineffective strains.

1978; Oxford University Press; Volume: 42; Issue: 9 Linguagem: Inglês

10.1271/bbb1961.42.1733

1881-1280

Shinsuke Ohta, Yoshihiro Kojima, Michihiko Yatazawa,

Polyamine Metabolism and Applications

Nicotine biosynthesis in tobacco callus tissues was investigated by comparing high nicotine producing strain OMT-53 with scarcely producing strain NT-5. NT-5 strain which had been subcultured for about 5 years with a medium containing 1.0 ppm 2, 4-D, produced very little amount of nicotine even after more than 47 subcultures on OT-23 medium containing 0.15ppm α-NAA. On the other hand, OMT-53 strain maintained a constant high level nicotine producing (ca. 2% or more on D. W. basis) capacity over 50 successive cultures on the same medium. The growth response of NT-S callus tissues to α-NAA concentration was quite different from that of OMT-53. Nicotine production assumed more distinctive patterns with these two strains. NT-5 strain never produced nicotine at any concentrations of α-NAA examined, whilst OMT-53 strain produced abundant amount of nicotine within a narrow range of α-NAA concentration having the optimal value of 0.15ppm. Nicotine supplemented to culture medium could not be decomposed either with NT-S or with OMT-53 callus tissues. The nicotine production by OMT-53 was not affected at moderate level (1mM) of supplemented nicotine, but at a very high level (5mM) of the supplemented nicotine, the nicotine production seemed to have been affected considerably. Some precursors supplemented to NT-5 callus cultures did not stimulate the nicotine biosynthesis at all, even though slightly positive effect was recorded with OMT-53 callus cultures. NT-5 callus tissues had much smaller pool size of total free amino acids than OMT-53. The ratio of each amino acid in total free amino acids was not so different between both callus tissues. On the basis of these results, some discussions were made on nicotine biosynthesis in tobacco tissue cultures.