Fungivory of mycorrhizal hyphae has a significant impact on fungal fitness and, by extension, on nutrient transfer between fungi and host plants in natural ecosystems. Mycorrhizal fungi have therefore evolved an arsenal of chemical compounds that are hypothesized to protect the hyphal tissues from being eaten, such as the protease inhibitors mycocypins. The genome of the ectomycorrhizal fungus Laccaria bicolor has an unusually high number of mycocypin-encoding genes. We have characterized the evolution of this class of proteins, identified those induced by symbiosis with a host plant and characterized the biochemical properties of two upregulated L. bicolor mycocypins. More than half of L. bicolor mycocypin-encoding genes are differentially expressed during symbiosis or fruiting body formation. We show that two L. bicolor mycocypins that are strongly induced during symbiosis are cysteine protease inhibitors and exhibit similar but distinct localization in fungal tissues at different developmental stages and during interaction with a host plant. Moreover, we show that these L. bicolor mycocypins have toxic and feeding deterrent effect on nematodes and collembolans, respectively. Therefore, L. bicolor mycocypins may be part of a mechanism by which this species deters grazing by different members of the soil food web.

中文翻译：

---

菌根诱导的 Laccaria bicolor 菌丝素是具有线虫毒性和跳虫拒食活性的强效蛋白酶抑制剂

菌根菌丝的食真菌对真菌适应性有显着影响，进而对自然生态系统中真菌和宿主植物之间的养分转移产生重大影响。因此，菌根真菌进化出了一系列化合物，这些化合物被假设用于保护菌丝组织不被吃掉，例如蛋白酶抑制剂菌丝菌素。外生菌根真菌Laccaria bicolor的基因组具有异常多的菌丝素编码基因。我们已经描述了这类蛋白质的进化，鉴定了与宿主植物共生诱导的蛋白质，并描述了两种上调L的生化特性。双色霉菌素。L的一半以上。双色在共生或子实体形成过程中，mycocypin 编码基因差异表达。我们证明了两个L。在共生过程中强烈诱导的双色菌丝菌素是半胱氨酸蛋白酶抑制剂，在不同发育阶段和与宿主植物相互作用期间在真菌组织中表现出相似但不同的定位。此外，我们证明了这些L。双色菌丝素分别对线虫和跳虫具有毒性和摄食威慑作用。因此，L。双色霉菌素可能是该物种阻止土壤食物网不同成员放牧的机制的一部分。