Expression of a cDNA for chloroplast ribosomal protein S16 of potato (Solanum tuberosum L.).

A cDNA encoding the potato (Solanum tuberosum L.) chloroplast ribosomal protein S16 (cp rps16) was isolated and characterized. The deduced amino acid sequence of the chloroplast rps16 coding sequence from potato shows 33% homology to the E.coli ribosomal protein S16 and 95% homology to the tobacco chloroplast ribosomal protein S16. The 13 amino acids encoded by exon-1 are highly conserved (100% identity) among higher plants. Two sizes of rps16 transcripts have been identified from northern blot analysis. The 1.5 kb transcript contains the 855 bp intron and represents an unprocessed RNA molecule, whereas the 0.7 kb transcript represents the mature form. The expression of rps16 is developmentally regulated, with transcript levels decreasing during tuber development and increasing during shoot development. The potato cp rps16 gene appears to be constitutively expressed in unswollen stolons and axillary buds, and its expression is enhanced by light.