Plant-parasitic cyst nematodes induce hypermetabolic syncytial nurse cells in the roots of their host plants. Syncytia are their only food source. Cyst nematodes are sexually dimorphic, with their differentiation into male or female strongly influenced by host environmental conditions. Under favourable conditions with plenty of nutrients, more females develop, whereas mainly male nematodes develop under adverse conditions such as in resistant plants. Here, we developed and validated a method to predict the sex of beet cyst nematode (Heterodera schachtii) during the early stages of its parasitism in the host plant Arabidopsis thaliana. We collected root segments containing male-associated syncytia (MAS) or female-associated syncytia (FAS), isolated syncytial cells by laser microdissection, and performed a comparative transcriptome analysis. Genes belonging to categories of defence, nutrient deficiency, and nutrient starvation were over-represented in MAS as compared with FAS. Conversely, gene categories related to metabolism, modification, and biosynthesis of cell walls were over-represented in FAS. We used β-glucuronidase analysis, qRT-PCR, and loss-of-function mutants to characterize FAS- and MAS-specific candidate genes. Our results demonstrate that various plant-based factors, including immune response, nutrient availability, and structural modifications, influence the sexual fate of the cyst nematodes.

中文翻译：

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宿主因素影响寄生于拟南芥根的线虫的性别。

植物寄生性囊肿线虫在其宿主植物的根部诱导代谢过度的合胞体哺乳细胞。合胞体是他们唯一的食物来源。囊肿线虫具有两性性，其分化成雄性或雌性受到宿主环境条件的强烈影响。在营养丰富的有利条件下，更多的雌性线虫生长，而主要的雄性线虫在不利条件下（例如抗性植物）生长。在这里，我们开发并验证了一种预测寄主植物拟南芥寄生过程中甜菜孢囊线虫（Heterodera schachtii）性别的方法。我们收集了包含男性相关合胞体（MAS）或女性相关合胞体（FAS）的根节段，通过激光显微切割分离了合胞体细胞，并进行了比较转录组分析。与FAS相比，MAS中属于防御，营养缺乏和营养饥饿类别的基因被过度代表。相反，在FAS中，与细胞壁的代谢，修饰和生物合成有关的基因类别过高。我们使用了β-葡萄糖醛酸苷酶分析，qRT-PCR和功能缺失突变体来表征FAS和MAS特异性候选基因。我们的结果表明，各种基于植物的因素，包括免疫应答，营养物质的利用和结构修饰，都会影响线虫的性命。我们使用了β-葡萄糖醛酸苷酶分析，qRT-PCR和功能缺失突变体来表征FAS和MAS特异性候选基因。我们的结果表明，各种基于植物的因素，包括免疫应答，营养物质的利用和结构修饰，都会影响线虫的性命。我们使用β-葡萄糖醛酸苷酶分析，qRT-PCR和功能丧失突变体来表征FAS和MAS特异性候选基因。我们的结果表明，各种基于植物的因素，包括免疫应答，营养物质的利用和结构修饰，都会影响线虫的性命。