Subcellular localization of SOT5 and tissue expression patterns of SOT5. A, Microscopy analysis of the YFP fusion protein SOT51-120-YFP transiently expressed in Arabidopsis protoplasts. The green fluorescence of SOT51-120-YFP was overlapped with chloroplast autofluorescence in merged images. DIC, Differential interference contrast microscopy. Bars = 10 µm. B, RT-PCR analysis of SOT5 expression in various tissues and seedlings. Total RNA was extracted from rosette and cauline leaves, stems, inflorescences, siliques, and roots of 40-d-old plants. Total RNA was extracted from 5-d-old seedlings grown in light or darkness or etiolated seedlings exposed to light for 4 h. Genomic DNA was used as a template control, and ACTIN expression was used as a loading control of RNA.