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

The cDNA of extracellular α‐l‐arabinofuranosidase (α‐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 α‐l‐AFase A protein of Aspergillus niger. The genomic DNA was cloned by PCR, and the nucleotide ligature sequence showed 18 exons and 17 introns. The first intron was upstream of the initiation codon. In situ hybridization revealed that the α‐l‐AFase gene is expressed in the root meristem, elongation zone and the root hair of carrot seedlings, indicating that this enzyme may participate in cell proliferation and development of carrot root cells.