Fig. 6

Northern blot analysis of mitochondrial ribosome-bound mRNA levels in different tobacco organs. Polysome gradients were fractionated into ten fractions, and equal aliquots of extracted RNAs were separated by denaturing agarose gel electrophoresis, blotted, and hybridized to radiolabeled probes specific for cox1 (a) and atp9 (b) The wedges above the blots indicate the gradient from low to high sucrose concentration. As a control, a sample was treated with puromycin to cause dissociation of ribosomes from the mRNAs. Northern blots presented here are representatives for three independent technical replicates. c Quantification of the band intensities of ribosome-bound mRNA shown in the Northern blots above. Values represent the ratio between polysomal and non-polysomal bands