Figure 4.

Analysis of Transcript Accumulation in cp29a and cp31a Mutants at 23 and 8°C.

Four micrograms of total leaf RNA from the indicated genotypes was fractionated on 1.2% agarose gels and analyzed by hybridization to probes for the plastid RNAs indicated (see Supplemental Table 1 online for primer sequences). Equal loading was controlled by staining the cytosolic 25S rRNA (25S) with methylene blue. Autoradiographs shown on the left are prepared with plants grown at normal temperatures; those on the right from plants cold-treated for 3 weeks.

(A) Transcript patterns with reductions (i.e., with quantitative but not qualitative changes in the transcript pattern) after cold treatment relative to wild-type controls.

(B) Genes with altered transcript patterns under cold stress conditions. Cartoons of the assessed operons are shown at the right. Selected transcripts are represented as well. Open boxes, cistrons; exons; lines, intergenic regions; dotted lines, introns.