松材线虫毒力及发育转型与细胞自噬关系研究

Research on the relationship of autophagy with the virulence and development of Bursaphelenchus xylophilus

采用透射电镜法对松材线虫的细胞自噬现象进行鉴认,并通过实时定量PCR的方法对不同毒力及不同发育期松材线虫的自噬基因BxAtg1和BxAtg8表达量进行测定。结果表明:饥饿诱导下不同毒力松材线虫存在细胞自噬现象,不同毒力松材线虫饥饿诱导12、24、36 h时,自噬基因BxAtg1表达量递减且趋势一致,而自噬基因BxAtg8在饥饿24 h时的强毒松材线虫体内表达量最高,在饥饿36 h时弱毒松材线虫体内表达量显著升高;与繁殖性松材线虫体相比,自噬基因BxAtg1和BxAtg8在扩散型3龄(JⅢ)和扩散型4龄幼虫(JⅣ)中的表达量均增加,推测自噬活性的调节机制可能与松材线虫的毒力相关,与松材线虫发育转型阶段的形态特征联系,暗示自噬可帮助松材线虫发育转型,从而提高松材线虫的适应性。

In order to identify the autophagy in Bursaphelenchus xylophilus, research on the relationship between autoph-agy and the different virulence and development of B. xylophilus was carried out in this paper. Transmission electron mi-croscopy （TEM） method was used to identify autophagy in B. xylophilus, and quantitative reverse transcription PCR （ qRT-PCR） was adopted to quantify the BxAtg1 and BxAtg8 at different virulence and at different stages of the develop-ment of B. xylophilus. The results from TEM observations showed that the process of autophagy existed in B. xylophilus after starvation-induced. The mRNA expression of BxAtg1 was decreased in different virulence nematodes which exposed to long-term starvation for 12, 24 and 36 h. The mRNA expression of BxAtg8 in strongly virulent nematodes was increased in 24 h, but the mRNA expression of BxAtg8 in weakly virulent nematodes was obviously increased in 36 h. And there was increment of both the mRNA expression of BxAtg1 and BxAtg8 in JⅢand JⅣcompared to the propagtive form of B. xylophilus. Compareing to the morphological characteristics of the different development of Bursaphelenchus xylophilus. These suggest that the mechanism of autophagy activity regulating may be related to the virulence of nematodes and auto-phagy assisted the nematodes in entering dispersal phase, which improved their ability to adapt to the environment at the same time. This study provided fundamental information the autophagy of B. xylophilus.