Identification of Novel Endo- β-1, 4-glucanase Isoforms from Bursaphelenchus Species (Nemtoda: Aphelenchoididae)

Bursaphelenchus xylophilus has been recognized as a causal pathogen of pine wilt disease (PWD). In order to identify relevant molecular biomarkers, we selected a variable region of endo-β-1, 4-glucanase (β 14-gcn) which was cloned from the cDNA of B. xylophilus and B. mucronatus. We then identified three novel β14-gcn isoforms: Bm-β 14-gcn and Bm-β 14-gcni from B. mucronatus, and Bx-β 14-gcn from B. xylophilus. Bm-β 14-gcn and Bx-β 14-gcn were found to be identical, whereas Bm-β 14-gcni was unique to B. mucronatus. These isoforms are Bursaphelenchus-specific and may be employed as molecular markers for the diagnosis of PWD. Our phylogenetic analysis showed that these β 14-gcns from Bursaphelenchus species were associated most closely with fungal β 14-gcns.