title: Expression of the gene coding for the small subunit of ribulosebisphosphate carboxylase during differentiation of tobacco plant protoplasts.
abstract: A hybridization probe was used to study the regulation of expression of the gene coding for the small subunit of ribulose 1,5-bisphosphate carboxylase, during functional differentiation of protoplasts. A library of cDNA from poly(A)-containing RNA extracted from specially treated tobacco leaves was constructed in the plasmid pBR322 by blunt-end ligation. This library was screened by colony hybridization with 32P-labelled cDNA prepared from mRNA coding for the precursor of the small subunit. A positive colony was identified containing recombinant plasmids with a nucleotide sequence homologous to this mRNA. These plasmids, bound to diazobenzyloxymethylated cellulose paper, were then used as a hybridization probe. The results showed unambiguously that the small subunit was not transcribed in protoplasts but was transcribed in undifferentiated white and chlorophyll-containing green callus cultures derived from protoplasts. The discrepancy between these results and those obtained with classical techniques is discussed.
mesh_terms: D002262:Carboxy-Lyases / Q000235:genetics*; D004274:DNA, Recombinant; D005815:Genetic Code; D010947:Plants, Toxic; D011523:Protoplasts / Q000201:enzymology*; D012273:Ribulose-Bisphosphate Carboxylase / Q000235:genetics*; D014026:Nicotiana / Q000201:enzymology* / Q000235:genetics; D014158:Transcription, Genetic
chemical_list: D004274:DNA, Recombinant; D002262:Carboxy-Lyases; D012273:Ribulose-Bisphosphate Carboxylase