Nuclear and polysomal transcripts of T-DNA in octopine crown gall suspension and callus cultures

Abstract

To establish a detailed map of the transcribed parts of the T-DNA in two octopine crown gall lines grown in suspension culture, T-DNA-derived steady-state nuclear and polysomal RNA as well as RNA synthesized in isolated nuclei purified from the crown gall tissues, was analyzed by southern blot hybridization to specific fragments of the T-region of the octopine plasmid pTi ACH5. In addition total RNA isolated from the same lines grown as callus tissue on solid agar, was analyzed for T-DNA specific transcripts. The results show that all of the T-DNA is transcribed although different segments are transcribed to significantly different extents. Roughly the same hybridization pattern was found for nuclear and polysomal poly-A+ and poly-A- RNA. The transcription pattern was found to be different for cells in the stationary phase of growth compared with actively growing cells.