Nucleotide polymorphism in the carrot late embryogenesis abundant gene DC8/ECP63

Carrot (Daucus carota) somatic embryogenesis has been extensively used as an experimental system for studying embryogenesis. In several plant species, late embryogenesis abundant (LEA) genes are reported as the embryogenesis-related genes that are specifically expressed in embryonic tissues. Several LEA genes have been isolated for carrot somatic embryogenesis. The carrot LEA genes DC8 and ECP63 have very similar nucleotide sequences, and the gene pair is likely to be a nucleotide polymorphism. In several carrot cultivars, plants in which only DC8 was detected (DD genotype), only ECP63 was detected (EE genotype), and both DC8 and ECP63 were detected (DE genotype) have been observed via genomic PCR. Furthermore, distinct frequencies of the genotypes were observed in some carrot cultivars. These results suggested that detection of the nucleotide polymorphism might be useful in defining carrot cultivars. In addition, DC8 and ECP63, which include 14 amino acid insertions/deletions and 21 amino acid substitutions, may have similar effects on somatic embryogenesis, as all genotypes (DD, DE, and EE) were detected in some embryogenic cell lines. Therefore, the nucleotide polymorphism may be a useful candidate polymorphic marker that is easily detectable by PCR.