Abstract: By comparing the expression pattern of cytochrome P450 (CYP450) genes of Pine Wood Nematode (PWN) (Bursaphelenchus xylophilus)and the accumulation of pine terpene, the relationship between the CYP450 genes of PWN and the metabolism of pine pinene was analyzed to provide fundamental information for PWN pathogenic mechanisms study. [Method] Five-years Pinus massoniana were inoculated with PWN. Real-time Quantitative PCR was conducted to detect expression patterns of apin gene of pine trees and CYP450 family genes of PWN. Terpene metabolism in infected P. massoniana was detected by Gas Chromatography. [Result] The expression of pinene synthase genes were dramatically induced at 6 dpi (days post inoculation) and 21 dpi. Both α-pinene and β-pinene were accumulated with two peaks at 9dpi and 27dpi, respectively. Correspondingly, the expression of PWN CYP-33C9 dramatically increased at 12dpi and 15dpi, and the expression of CYP-33C4 were highest at 21dpi. [Conclusion] The pine tree pinene synthase gene was highly induced by PWN inoculation which resulted in sharp accumulation of the α-pinene and β-pinene. In responding to the accumulation of pine terpene, the expression of PWN CYP450 genes dramatically increased. Therefore, according to the temporal correlation between the pinene metabolism and the PWN CYP450 genes expression we inferred that the PWN CYP450 genes might participate in the terpene metabolism and might be one of the pathogenic genes in the PWN pathogenic process.

Key words: pine wood nematode, terpene metabolism, cytochrome P450, pathological mechanisms