背景:Arthrobotrys寡孢子菌已被用作模型菌株来研究真菌和线虫之间的相互作用,因为它能够通过开发专门的陷阱来捕获线虫。先前的研究表明,高渗透压甘油(Hog1)信号调节A的渗透调节和杀线虫活性。然而,线虫捕获(NT)真菌中Hog1信号的下游转录因子的功能尚不清楚。
目的:本研究旨在探讨寡孢菌Hog1信号通路下游转录因子AoMsn2的功能和潜在调控网络。
方法:使用靶向基因缺失来表征AoMsn2的功能,表型实验,实时定量PCR,RNA测序,非靶向代谢组学,和酵母双杂交分析。
结果:Aomsn2的丢失使菌丝明显增大和肿胀,随着间隔的增加和细胞核的显着减少。特别是,孢子产量,孢子发芽率,陷阱,突变体的线虫捕食效率显着降低。表型和转录组学分析显示,AoMsn2对于脂肪酸代谢和自噬途径至关重要。此外,非靶向代谢组学分析确定了AoMsn2在调节次级代谢产物中的重要功能。更进一步,我们基于京都基因百科全书和基因组通路图和在线网站STRING分析了AoMsn2的蛋白质相互作用网络。最后,通过Y2H分析鉴定了Hog1和AoMsn2的6种推定的靶向蛋白。
结论:我们的研究表明,AoMsn2在生长中起着至关重要的作用,分生孢子,陷阱发展,脂肪酸代谢,和次生代谢,以及为理解NT真菌陷阱形态发生和环境适应的调节机制奠定了广泛的基础。
BACKGROUND: Arthrobotrys oligospora has been utilized as a model strain to study the interaction between fungi and nematodes owing to its ability to capture nematodes by developing specialized traps. A previous study showed that high-osmolarity glycerol (Hog1) signaling regulates the osmoregulation and nematocidal activity of A. oligospora. However, the function of downstream transcription factors of the Hog1 signaling in the nematode-trapping (NT) fungi remains unclear.
OBJECTIVE: This study aimed to investigate the functions and potential regulatory network of AoMsn2, a downstream transcription factor of the Hog1 signaling pathway in A. oligospora.
METHODS: The function of AoMsn2 was characterized using targeted gene deletion, phenotypic experiments, real-time quantitative PCR, RNA sequencing, untargeted metabolomics, and yeast two-hybrid analysis.
RESULTS: Loss of Aomsn2 significantly enlarged and swollen the hyphae, with an increase in septa and a significant decrease in nuclei. In particular, spore yield, spore germination rate, traps, and nematode predation efficiency were remarkably decreased in the mutants. Phenotypic and transcriptomic analyses revealed that AoMsn2 is essential for fatty acid metabolism and autophagic pathways. Additionally, untargeted metabolomic analysis identified an important function of AoMsn2 in the modulation of secondary metabolites. Furtherly, we analyzed the protein interaction network of AoMsn2 based on the Kyoto Encyclopedia of Genes and Genomes pathway map and the online website STRING. Finally, Hog1 and six putative targeted proteins of AoMsn2 were identified by Y2H analysis.
CONCLUSIONS: Our study reveals that AoMsn2 plays crucial roles in the growth, conidiation, trap development, fatty acid metabolism, and secondary metabolism, as well as establishes a broad basis for understanding the regulatory mechanisms of trap morphogenesis and environmental adaptation in NT fungi.