Molecular cloning and characterization of the psbL and psbJ genes for Photosystem II from Panax ginseng

We have cloned and characterized two genes for Photosystem It from chloroplasts of Panax ginseng. These genes, psbL and psbJ, comprise 117 and 123 nucleotides, respectively. When compared with monocots, dicots, or liverwort, the overall amino acid sequence identity of the former is >97%, whereas that of the latter is approximately 95 to 100%. Southern blot analysis revealed that a single copy of each gene exists in the chloroplast genome. Our Northern blot analysis indicated that psbL and psbJ are co-transcribed as a polycistron and are not subjected to further processing into smaller transcripts. We also determined that varying daylight intensities (5, 10, 20, or 100%) did not significantly change the level of in vivo accumulation of psbLJ transcript.