Chemical Signals Synchronize the Life Cycles of a Plant-Parasitic Nematode and Its Vector Beetle
Chemical Signals Synchronize the Life Cycles of a Plant-Parasitic Nematode and Its Vector Beetle
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化学信号同步植物寄生线虫及其媒介甲虫的生命周期
DOI：
10.1016/j.cub.2013.08.041
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发表时间：
2013-10-21
期刊：
影响因子：
9.2
通讯作者：
Sun, Jianghua
中科院分区：
文献类型：
--
作者：
Zhao, Lilin;Zhang, Shuai;Sun, Jianghua
松材线虫松材线虫(Bursaphelenchus xylophilus)对世界大部分地区的松林造成了严重损害[1-4]。当这种植物寄生线虫在受感染的松树内遇到其昆虫媒介松墨天牛甲虫后，发育到第四幼虫阶段（L-IV）时，就会发生这种植物寄生线虫的扩散[5-9]。在这里，我们发现松材线虫中 L-IV 的形成是由 C16 和 C18 脂肪酸乙酯 (FAEE) 诱导的，这些脂肪酸乙酯在媒介甲虫的体表上大量产生，特别是在发育后期的蛹、新出现的成虫和新羽化的成虫阶段。然后，L-IV 可以进入成年甲虫的气管系统，并扩散到新的松树上。用长链 FAEE 或 PI3 激酶抑制剂 LY294002 处理松材线虫，可促进 L-IV 形成，而 Delta(7)-dafachronic 酸可阻断这些化学物质的作用，表明胰岛素/IGF-1 和 DAF-12 途径在 L-IV 形成中发挥保守作用。我们的工作提供了一种机制，通过该机制，松材线虫中 L-IV 的形成与其媒介甲虫的生命周期特异性协调。了解控制 L-IV 发育决定的化学信号可用于干扰这种植物寄生线虫的传播。
The pinewood nematode Bursaphelenchus xylophilus has caused severe damage to pine forests in large parts of the world [1-4]. Dispersal of this plant-parasitic nematode occurs when the nematode develops into the dispersal fourth larval stage (L-IV) upon encountering its insect vector, the Monochamus pine sawyer beetle, inside an infected pine tree [5-9]. Here, we show that L-IV formation in B. xylophilus is induced by C16 and C18 fatty acid ethyl esters (FAEEs), which are produced abundantly on the body surface of the vector beetle specifically during the late development pupal, emerging adult, and newly eclosed adult stages. The L-IV can then enter the tracheal system of the adult beetle for dispersal to a new pine tree. Treatment of B. xylophilus with long-chain FAEEs, or the PI3 kinase inhibitor LY294002, promotes L-IV formation, while Delta(7)-dafachronic acid blocks the effects of these chemicals, suggesting a conserved role for the insulin/IGF-1 and DAF-12 pathways in L-IV formation. Our work provides a mechanism by which L-IV formation in B. xylophilus is specifically coordinated with the life cycle of its vector beetle. Knowledge of the chemical signals that control the L-IV developmental decision could be used to interfere with the dispersal of this plant-parasitic nematode.