Isolation and Characterization of Putative Acetyl-CoA Carboxylases in Arachis hypogaea L.

Candidate genes of multisubunit (MS) and multifunctional (MF) acetyl-CoA carboxylase (ACCase) including accB1, accB2, accC, accA, accD, and MF-ACCase were isolated from peanut by sequencing a full-length cDNA library and homology-based cloning. Primary structures of peanut ACCases were highly conserved, especially biochemical function domains, compared with other higher plants and Escherichia coli. The numbers of homologs of each ACCase gene expressed in developing seed of peanut varied from two to five. Two editing sites of peanut accD were identified by comparing genomic DNA and its corresponding cDNAs. The MS-ACCase of Arachis hypogaea and Arabidopsis thaliana shared a conservative structure of gene organization. Semi-quantitative reverse transcription polymerase chain reaction analysis indicated that MS-ACCase and MF-ACCase genes were expressed in all peanut tissues examined, but their mRNA expression level were quite different. In peanut seed development, accC, accA, accD, and MF-ACCase mRNAs were expressed strongly at 60 days after pegging.