Endophytic bacteria expressing β-glucuronidase cause false positives in transformation of Dioscorea species
- Cite this article as:
- Tör, M., Mantell, S.H. & Ainsworth, C. Plant Cell Reports (1992) 11: 452. doi:10.1007/BF00232689
False positive transformants obtained during plant transformation experiments on species of the monocotyledonous genus Dioscorea (yam) are described. The false positive results were found to be due to endophytic bacteria which exist within aseptically micropropagated shoot cultures and which express β-glucuronidase (GUS). The bacteria were isolated and identified as two species of Curtobacterium. The expression of GUS in these organisms was found to be induced by a variety of glucuronide substrates. The induction of GUS activity in the bacteria can be inhibited by chloramphenicol, tetracycline, ticarcillin and sodium azide. Implications of these results for use of the gus gene in plant transformation work are discussed.
Keywordsβ-GlucuronidaseDioscoreaendophytic bacteriafalse positive transformants
Ethylenediamine tetra-acetic acid
Enzyme-linked immuno-sorbent assay
Sodium dodecyl sulphate