线虫病原真菌与宿主线虫的相互作用是研究植物线虫生物防治的关键问题。不同于腐生阶段中菌丝生长与产孢的快速转换的生活方式，线虫卵寄生真菌淡紫拟青霉侵染线虫卵的整个过程中维持大量菌丝的生长并抑制孢子产生。这种生长方式有利于高效侵染的进行，但其中的生长调节机制并不清楚。前期研究发现线虫卵壳几丁质的降解产物N-乙酰葡糖胺（GlcNAc）可以抑制淡紫拟青霉分生孢子的产生，并且外源添加GlcNAc可以提高该菌对线虫卵的侵染能力。本项目拟在前期研究的基础上，借鉴模式真菌产孢调控通路，通过转录组分析，突变体库筛选并结合基因敲除和回补等方法鉴定GlcNAc抑制淡紫拟青霉产孢信号转导途径中的关键基因。通过比较突变菌株产孢和卵寄生能力的变化分析GlcNAc抑制产孢的机制及其在真菌侵染线虫卵过程中的作用，为深入理解真菌侵染线虫卵的分子机制，高效利用该类真菌控制植物寄生线虫奠定基础。

The interaction of nematode-parasitic fungi and their hosts is a key issue for biological control of plant-parasitic nematodes. When living as a saprophyte, the nematode-egg-parasitic fungus Paecilomyces lilacinus finishes a life cycle by fast switching between mycelial growth and sporulation. But when infecting nematode eggs, it maintains mycelia branch and extension but inhibits conidiation. This living strategy is favorable for infection, but the mechanism of the regulation is unknown. Our previous study showed that the degrading product of the egg shell chitin, N-acetylglucosamine (GlcNAc), could inhibit conidiation of P. lilacinus. Meanwhile, adding GlcNAc in the media could promote egg infection by the fungus. In this project, our goal is to find key genes involved in the conidiation inhibition. Firstly, we find candidate genes by screening homolog genes of conidiation regulation in model fungi like Aspergillus spp. and, by transcriptome analysis and screening mutation library. Then, these candidate genes were characterized by gene knockout and complementation. Last, we study the role of conidiation inhibition in infection of nematode eggs by comparison the infection rates of mutants of involved genes with wild type strain. All of these study is to achieve in-depth understanding of fungal infection of nematode eggs, and using them to control plant-parasitic nematodes with high efficiency.