Molecular cloning and in situ hybridization of alpha-L-arabinofuranosidasefrom carrot cells

The cDNA of extracellular alpha -L-arabinofuranosidase (alpha -L-AFase, EC 3.2.1.55) secreted from suspension-cultured carrot cells (Daucus carota L. cv. Kintoki) was isolated and characterized. The nucleotide sequence of the cDNA (2.4 kb) revealed an open reading frame consisting of 655 amino acid residues. Sequence homology research showed 28.4% identity to the alpha -L- AFase A protein of Aspergillus niger. The genomic DNA was cloned by PCR, an d the nucleotide sequence showed 18 exons and 17 introns. The first intron was upstream of the initiation codon. In situ hybridization revealed that t he AFase gene is expressed in the root meristem, elongation zone and the ro ot hair of carrot seedlings, indicating that this enzyme may participate in cell proliferation and development of carrot root cells.