Molecular characterization of cDNAs encoding 3-hydroxy-3-methylglutaryl coenzyme A reductase in marigold (Tagetes erecta)

A marigold flower cDNA library was constructed and two cDNAs (hmg1 and hmg2) encoding 3-hydroxy-3-methylglutaryl coenzyme A reductase (HMGR) were isolated and sequenced. The hmg1 cDNA encodes HMGR1, an enzyme consisting of 574 amino acid residues with a putative molecular weight of 61.9 Ku, while hmg2 encodes a truncated form of the enzyme lacking the 90 amino acid residues present at the C-terminus of HMGR1. The two cDNAs have identical 3'- and 5'-untranslated regions. Southern blot analysis revealed the presence of three or more genomic sequences of marigold showing homology to the hmg1 cDNA, while Northern blot analysis detected at least two different size patterns of HMGR mRNAs in flowers, leaves, and roots.