Functional analysis of the cellulose gene of the pine wood nematode, Bursaphelenchus xylophilus, using RNA interference.

Cellulases are pathogenic substances suspected to be responsible for the development of the early symptoms of nematode disease. The pine wood nematode, Bursaphelenchus xylophilus (Parasitaphelenchidae), is the causal agent of pine wilt disease, which kills millions of pine trees. We used RNA interference (RNAi), a reverse genetic tool, to analyze the function of the endo-β-1,4-glucanase gene of B. xylophilus, which causes the most serious forest tree disease in China and the rest of eastern Asia. Silencing of this gene was detected through real-time PCR and cellulase activity assays after soaking for 24 h in dsRNA. The cellulase gene silencing effects differed among various siRNAs. The propagation and dispersal ability of these nematodes decreased when the endo-β-1,4-glucanase gene was silenced. It is important to select an effective siRNA before performing an RNAi test.