Species displacement facilitated by ascarosides between two sympatric sibling species: a native and invasive nematode
Species displacement facilitated by ascarosides between two sympatric sibling species: a native and invasive nematode
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蛔苷促进两个同域同胞物种之间的物种置换：本地线虫和入侵线虫
DOI：
10.1007/s10340-020-01206-w
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发表时间：
2020-02-21
影响因子：
4.8
通讯作者：
Sun, Jianghua
中科院分区：
文献类型：
--
作者：
Meng, Jie;Wickham, Jacob D.;Sun, Jianghua
竞争置换是种间竞争的最极端结果，也是入侵物种成为成功入侵者的重要策略。松材线虫松材线虫是引起松材线虫病和全球检疫性有害生物的病原，在其入侵过程中，松材线虫通常会取代当地共处的同胞物种松材线虫。尽管出现了这种普遍的结果，但这种流离失所背后的驱动力仍然难以捉摸。蛔虫苷是一类进化保守的线虫信息素家族，在结构和功能上具有多样性。我们假设这些线虫信息素在物种置换中发挥作用。为了验证这一假设，我们比较了B的蛔虫苷成分。嗜木霉和B。用LC-MS/MS和生物测定法测定了两种线虫对天然和人工合成的蛔虫苷的反应。结果表明，Asc-C5(Ascr#9)是两种线虫信息素组成中含量最丰富的一种，在竞争条件下，松材线虫的生长速度较快。此外，低浓度的粗制和人工合成的蛔虫苷[Asc-C5、Asc-C6(Ascr#12)及其混合物]提高了雌蜂的繁殖力和体长生长。嗜木症，但不是INB。粘毛虫。相比之下，体长Ob。粘虫被其自身的蛔虫苷粗提物和合成的蛔虫苷(ASC-C5、ASC-C6及其混合物)抑制。我们的结果有力地表明，蛔虫苷在两种线虫之间的竞争置换中发挥了作用，这可以解释观察到的INB现象。松材线虫入侵森林，其中B。毛滴虫广泛存在于ToB之前。松材线虫入侵。
Competitive displacement is not only the most extreme outcome of interspecific competition, but also an important strategy for invasive species to be successful invaders. Pinewood nematode,Bursaphelenchus xylophilus, the causal agent for pine wilt disease and global quarantine pest, usually displacesBursaphelenchus mucronatus, a native sympatric sibling species, during its invasion process. Despite this prevalent outcome, the driving forces behind this displacement remain elusive. Ascarosides, an evolutionarily conserved family of nematode pheromones, are versatile in structure and function. We hypothesize these nematode pheromones play a role in species displacement. To investigate this hypothesis, we compared the ascarosides composition ofB. xylophilusandB. mucronatusby LC–MS/MS followed by bioassays to test the responses of two nematodes to both crude and synthetic ascarosides. We found that asc-C5 (ascr#9) was the most abundant component and that there were no differences in pheromone composition between the two nematode species.B. xylophilushad faster growth rates under competition conditions. Furthermore, low concentrations of both crude and synthetic ascarosides [asc-C5, asc-C6 (ascr#12) and their mixture] enhanced female fecundity and body length growth inB. xylophilusbut not inB. mucronatus. In contrast, body length ofB. mucronatuswas suppressed by a crude extract of its own ascarosides as well as by synthetic ascarosides (asc-C5, asc-C6 and their mixture). Our results strongly suggest that ascarosides play a role in the competitive displacement between two nematode species, which could explain the phenomena observed inB. xylophilus-invaded forests whereB. mucronatuswidely existed prior toB. xylophilusinvasion.