Fig. 2: SOP10 binds to the nad4 and nad5 transcripts and affects splicing of their first intron.
a Subcellular localization of SOP10 and sop10-1 in rice protoplasts. The mutation in sop10-1 protein did not change its location in mitochondria. OMP25-RFP was used as a mitochondrial marker. The numbers on right side of each panel show how often this representative subcellular localization pattern occurred, relative to total examined cells. Scale bars, 5 μm. b Relative expression levels of nad4 and nad5 in 9311, ospus1-1 mutant, suppressors of ospus1-1 (ospus1-1 sop10-1 and three ospus1-1 sop10CR lines) and ospus1-1 sop10-1 complementation (comp) plants at 28 °C and 22 °C. The relevant raw data are reported in Supplementary Data 1. Values are means ± S.D. (n = 6) of three biological replicates. Differences between ospus1-1, sop10 mutants, complementation lines (comp) and wild type are determined by unpaired Student’s t-test (two-tailed). Exact P-values are shown. c Northern blot analysis to detect the nad4 and nad5 transcripts. Total RNA was extracted from seedlings of 9311, ospus1-1, four suppressors of ospus1-1, and comp plants grown at 28 °C and 22 °C. The specific fragments of nad4 and nad5 used as the probes. Red triangles indicate the intron retention in nad4. Methylene blue staining (MB stain) is shown as a loading control. Experiments were repeated three times with similar results. Source data for c are provided as a Source Data file. d The interaction of SOP10 with nad4 and nad5 transcripts demonstrated by RNA immunoprecipitation (RIP). S1 and S2 represent the specific fragments of nad4 used for RIP RT-PCR; S3 and S4 represent the specific fragments of nad5 used for RIP RT-PCR. RIP assays were performed with anti-FLAG and anti-IgG antibodies in 9311 and SOP10-FLAG transgenic calli. 0.1% of total RNA was used as input. ACTIN was used as the negative control. Experiments were repeated two times independently with similar results.
