Arabidopsis thaliana ECP63 encoding a LEA protein is located in chromosome 4

DCECP63 is a carrot embryogenic cell protein. To perform its genetic analysis, we isolated an Arabidopsis thaliana (At) ECP63 cDNA. The cDNA encoded a polypeptide of 449 amino acids (aa). Its deduced aa sequence showed extensive similarity with DCECP63, DCDC8 and BPBP8 which are embryonic proteins isolated from carrot and birch, respectively. The aa sequence contained eight well-conserved tyrosine phosphorylation sites and 16 repeats of 11 aa. Southern analysis showed that the AtECP63 gene might belong to a small multigene family. The AtECP63 transcripts accumulated specifically in mature seeds, and exogenous abscisic acid (ABA) induced its expression in immature siliques, but not in vegetative tissues. These results suggested that the AtECP63 gene encoding a putative phosphotyrosine protein belonging to late embryogenesis abundant (LEA) protein in group 3 might be involved in maturation and desiccation tolerance of seeds. Restriction fragment length polymorphism (RFLP) and cleaved amplified polymorphic sequence (CAPS) mapping showed that AtECP63 gene was present in the South part of chromosome 4.