An alternative cytokinin biosynthesis pathway
AUTOR(ES)
Åstot, Crister
FONTE
The National Academy of Sciences
RESUMO
Studies of de novo cytokinin biosynthesis in isopentenyltransferase (ipt)-transformed Arabidopsis thaliana, involving in vivo deuterium labeling and mass spectrometry, showed that the biosynthetic rate of zeatinriboside-5′-monophosphate was around 66-fold higher than that of isopentenyladenosine-5′-monophosphate (iPMP), the proposed primary product of the Agrobacterium ipt. Double tracer analysis, using [2H6] isopentenyladenosine and deuterium oxide, provided evidence for an alternative, iPMP-independent, biosynthetic pathway for zeatin-type cytokinins, present in both ipt-expressing and wild-type Arabidopsis thaliana. Reduction of the biosynthetic flux in the alternative pathway by use of mevastatin, an inhibitor for 3-hydroxy-3-methylglutaryl CoA reductase, indicated a terpenoid origin for the side-chain precursor of the iPMP independent pathway.
ACESSO AO ARTIGO
http://www.pubmedcentral.nih.gov/articlerender.fcgi?artid=18995Documentos Relacionados
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