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Suspension cultured transgenic cells of Nicotiana tabacum expressing tryptophan decarboxylase and strictosidine synthase cDNAs from Catharanthus roseus produce strictosidine upon secologanin feeding
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Orientador(es)
Resumo(s)
A transgenic cell suspension culture of Nicotiana tabacum L. ‘Petit Havana’ SR1 was established expressing tryptophan decarboxylase and strictosidine synthase cDNA clones from Catharanthus roseus (L.) G. Don
under the direction of cauliflower mosaic virus 35S promoter and nopaline synthase terminator sequences. During a growth cycle, the transgenic tobacco cells showed
relatively constant tryptophan decarboxylase activity and
an about two- to sixfold higher strictosidine synthase activity, enzyme activities not detectable in untransformed
tobacco cells. The transgenic culture accumulated tryptamine and produced strictosidine upon feeding of secologanin, demonstrating the in vivo functionality of the two
transgene-encoded enzymes. The accumulation of strictosidine, which occurred predominantly in the medium, could
be enhanced by feeding both secologanin and tryptamine.
No strictosidine synthase activity was detected in the medium, indicating the involvement of secologanin uptake
and strictosidine release by the cells.
Descrição
Palavras-chave
Nicotiana tabacum Secologanin Terpenoid indole alkaloids Strictosidine synthase Tryptophan decarboxylase