Direct assessment of hormone stimulated transcription in protoplasts and isolated nuclei of Petunia hybrida.

We have developed a simplified procedure for the detection of cellular RNA transcripts. Entire protoplasts, isolated nuclei or nuclei sorted according to cell cycle phases are directly dotted onto filters and hybridized. Transcripts are quantified thereupon without any RNA extraction methodology. Previously, auxin and cytokinin have been shown to increase the level of RNA in Petunia mesophyll protoplasts after 18h of culture. The present results show that auxin and cytokinin also increase the level of ATPase and rDNA gene transcripts in protoplast released nuclei. For the ribosomal gene, however, transcripts increase in protoplasts with time in absence of exogenous hormones.