ISSN:
1399-3054
Source:
Blackwell Publishing Journal Backfiles 1879-2005
Topics:
Biology
Notes:
Using tobacco root cultures, we explored the possibility of a correlation between the expression of the rol genes from the TL-DNA (rolA, rolB, rolC) of Agrobacterium rhizogenes and changes in polyamine content and metabolism. Transgenic roots were induced by inoculation of Nicotiana tabacum cv. Xanthi leaf discs with a disarmed strain of A. tumefaciens harbouring the rolA, rolB and rolC genes either singly or in combination; the presence of these genes on the plant genome was confirmed by Southern blot analysis. Transgenic roots, especially those transformed either by a combination of the three rol genes (A+B+C) or the rolC alone, grew faster than the untransformed roots. Putrescine, spermidine and traces of spermine were present in all samples, both in free and bound forms. While rolA roots showed increased levels of free and bound polyamines as compared with controls, accumulation of polyamines in rolB and rolC roots was inhibited or mantained, with the exception of a 66 and 48% increase, respectively, in the PCA-soluble conjugated fraction. In roots transgenic for all three rol genes (A+B+C), the polyamine content remained almost unaltered compared with controls, suggesting that rolB and rolC genes could nullify or compensate the rolA effects. The higher polyamine contents found in roots transformed by rolA paralleled with higher ornithine (EC 4.1.1.17) and arginine (EC 4.1.1.19) decarboxylase activities as well as higher nicotine production. It is suggested that polyamine metabolism in root cultures is altered by expression of rol genes.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1111/j.1399-3054.1995.tb00866.x
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