MOLECULAR CHARACTERIZATION OF MULTIPLE CDNA CLONES FOR ADP-GLUCOSE PYROPHOSPHORYLASE FROM ARABIDOPSIS-THALIANA

PCR amplification of cDNA prepared from poly(A)+ RNA from aerial parts of Arabidopsis thaliana, using degenerate nucleotide primers based on conserved regions between the large and small subunits of ADP-glucose pyrophosphorylase (AGP), yielded four different cDNAs of ca. 550 nucl eotides each. Based on derived amino acid sequences, the identities be tween the clones varied from 49 to 69%. Sequence comparison to previou sly published cDNAs for AGP from various species and tissues has revea led that three of the amplified cDNAs (APL1, ApL2 and ApL3) correspond to the large subunit of AGP, and one cDNA (ApS) encodes the small sub unit of AGP. Both ApL1 and ApS were subsequently found to be present i n a cDNA library made from Arabidopsis leaves. All four PCR products a re encoded by single genes, as found by genomic Southern analysis.