Expression Profiling of Autophagy Genes BxATG1 and BxATG8 under Biotic and Abiotic Stresses in Pine Wood Nematode Bursaphelenchus xylophilus

The pine wood nematode (PWN), Bursaphelenchus xylophilus, is the pathogen of pine wilt disease (PWD) and causes huge economic losses in pine forests and shows a remarkable ability to survive under unfavorable and changing environmental conditions. This ability may be related to autophagy, which is still poorly understood in B. xylophilus. Our previous studies showed that autophagy exists in PWN. Therefore, we tested the effects of autophagy inducer rapamycin on PWN and the results revealed that the feeding rate and reproduction were significantly promoted on fungal mats. The gene expression patterns of BxATG1 and BxATG8 under the different stress were determined by quantitative reverse transcription PCR (qRT-PCR). We tested the effects of RNA interference on BxATG1 and BxATG8 in PWN during different periods of infection in Pinus thunbergii. The results revealed that BxATG1 and BxATG8 may play roles in allowing PWN to adapt to changing environmental conditions and the virulence of PWN was influenced by the silence of autophagy-related genes BxATG1 and BxATG8. These results provided fundamental information on the relationship between autophagy and PWN, and on better understanding of gene function of BxATG1 and BxATG8 in PWN.