Pine chemical volatiles promote dauer recovery of a pine parasitic nematode, Bursaphelenchus xylophilus
Pine chemical volatiles promote dauer recovery of a pine parasitic nematode, Bursaphelenchus xylophilus
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松树化学挥发物促进松树寄生线虫松材线虫的持续恢复
DOI：
10.1017/s0031182019001264
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发表时间：
2020-01-01
期刊：
影响因子：
2.4
通讯作者：
Zhang，Xingyao
中科院分区：
文献类型：
--
作者：
Zhang，Wei;Li，Yongxia;Zhang，Xingyao
松材线虫（Bursaphelenchusxylophilus）是一种松树寄生线虫，在全球范围内对其寄主松林构成严重威胁。当扩散期幼虫4（dauer，DL 4）为B.松材线虫进入新生松树后，蜕皮为繁殖成虫（dauer recovery），迅速繁殖，杀死寄主松树。在这里，我们发现松树的化学挥发物，而不是常见的dauer恢复因素的线虫（如适宜的温度，养分的可用性或密度），促进B。松材线虫恢复结果表明，寄主松树体内化学物质的挥发对DL 4有一定的吸引作用，促进了DL 4的恢复。为了确定哪些化学物质促进这一过程，我们确定了刺激活性的主要挥发物的松树，包括六个单萜和两个倍半萜。结果表明，6种单萜均能促进Dauer转化，尤其是β-蒎烯和β-月桂烯，而两种倍半萜对Dauer转化没有影响。此外，β-蒎烯对Dauer回复率有梯度效应。我们推测，当DL 4感染松树，松树的挥发物释放的喂养伤口被用作化学信号的DL 4转化为成人繁殖和迅速杀死松树。我们的研究确定了B。恢复化学信号，可能有助于防治松树枯萎病。
Pinewood nematode, Bursaphelenchus xylophilus, a pine parasitic nematode, poses a serious threat to its host pine forests globally. When dispersal-stage larvae 4 (dauer, DL4) of B. xylophilus enters the new pine, it moults into propagative adult (dauer recovery) and reproduces quickly to kill the host pine. Here, we found pine chemical volatiles, rather than the common dauer recovery factors of nematodes (e.g. suitable temperatures, nutrient availability or density), promote B. xylophilus dauer recovery. The results showed that volatilization of chemicals in host pines could attract DL4 and promote DL4 recovery. To identify which chemicals promote this process, we determined the stimulated activity of the main volatiles of pines including six monoterpenes and two sesquiterpenes. Results showed that all the six monoterpenes promoted dauer recovery, especially β-pinene and β-myrcene, but the two sesquiterpenes have no effect on the transformation. Furthermore, β-pinene performed gradient effects on dauer recovery. We hypothesized that when DL4 infect pine trees, the pine volatiles released from the feeding wounds are used as chemical signals for DL4 transformation to adult to reproduce and rapidly kill the pines. Our study identified the B. xylophilus dauer recovery chemical signal and may contribute to preventing pine wilt disease.