CLONING AND CHARACTERIZATION OF PLASTID RIBOSOMAL-PROTEIN S16 GENE FROM POTATO (SOLANUM-TUBEROSUM L. CV DESIREE)

The plastid ribosomal protein s16 (rps16) gene was cloned from potato (Solanum tuberosum L. ssp. tuberosum cv Desiree) by PCR amplification to obtain a new homologous recombination site of plastid transformatio n. The potato rps16 genomic clone was 1627 bp in size and the coding r egion was interrupted by an 859 bp intron. Exon I was 40 bp, encoding 13 amino acids and exon II was 227 bp, encoding a 76 amino acid polype ptide, The nucleotide sequence of the rps16 gene from the ''Desiree'' potato shared perfect identity with the sequence from the ''Superior'' potato in the coding region, Three nucleotide substitutions, two nucl eotide insertions, and one nucleotide deletion mere found between the intron sequence of both ''Desiree'' and ''Superior'' cultivars. The am ino acid sequence of the potato rps16 gene showed a high level of iden tity with rice, maize, tobacco, and mustard (84-94%) and a relatively low level compared with Bacillus stearothermophilus and E. coli (27-28 %). Expression of the rps16 gene was strong in chloroplasts and transc ripts were delectable in amylopasts, suggesting that the rps16 gene is active in nonphotosynthetic plastids as well as in photosynthetic pla stids. These results indicate that the potato rps16 gene can be used a s a new homologous recombination site of plastid transformation for po tato cultivars.