Characterization of a birch (Betula pendula Roth.) embryogenic gene, BP8.

We have isolated the birch homologue (BP8) for the carrot embryogenic gene DC8 by heterologous hybridization. The birch BP8 gene encodes a putative protein of 53 kDa, showing 52% sequence identity with the DC8 gene at the amino acid level. The putative BP8 protein contains 20 repeats of 11 amino acids and thus belongs to the group of LEA proteins isolated from such plants as carrot, cotton and wheat. Northern hybridization of mRNA isolated from birch cells representing different stages of somatic embryogenesis and non-embryogenetic material with a PB8 probe gave no signals, suggesting a low expression level of the BP8 gene.