Figure 8.

Chloroplast ribosome biogenesis in the atnusg mutant treated with cold stress. (A) Immunoblotting analysis of chloroplast ribosomal proteins in the atnusg mutant that was treated with cold stress; the wild type was used as a control. The components of the small 30S subunit, PRPS1(bS1c) and PRPS5(uS5c), and the components of the large 50S subunit, PRPL2(uL2c) and PRPL4(uL4c) were detected. Total protein samples were prepared from emerging leaves of cold stress-treated plants and then separated by SDS–PAGE. Immunoblotting analysis was carried out with antibodies against plastid ribosomal proteins. (B) Levels of chloroplast rRNAs (16S rRNA, 23S rRNA, 4.5S rRNA and 5S rRNA) in the atnusg mutant treated with cold stress; the wild type was used as a control. Total RNA from emerging leaves of the cold stress-treated plants was analysed with specific probes for chloroplast rRNA. Total RNA (5 μg) was loaded in each lane with the corresponding probes as shown above. The gels were stained with ethidium bromide (EtBr) to visualize the rRNA and used as loading controls. The sizes of distinct forms of rRNA species are shown.