GSE192443
Transcriptomic analysis reveals that Rho GTPases regulate trap development and lifestyle transition of the nematode-trapping fungus Arthrobotrys oligospora
Nematode-trapping (NT) fungi can form unique infection structures (traps) to capture and kill free-living nematodes, thus play a potential role in the biocontrol of nematodes. Arthrobotrys oligospora is a representative species of the NT fungi. Here we performed dual RNA-seq to understand the interaction between A. oligospora and Caenorhabditis elegans. We identified 5752 unique differentially expressed genes during trap formation and predation, and the rac gene was significantly upregulated. Alternative splicing events occurred in 896 2012 genes, including the rac and rho2 gene. Further, we characterized three Rho GTPases (Rho2, Rac, and Cdc42) in A. oligospora using gene disruption and multi-phenotypic analysis. The analyses showed that AoRac and AoCdc42 play an important role in mycelium growth, lipid accumulation, DNA damage, sporulation, trap formation, pathogenicity, and stress response in A. oligospora. Furthermore, AoCdc42 and AoRac specifically interacted with components of the Nox complex, thus regulating the production of reactive oxygen species. Furthermore, the transcript levels of several genes associated with the protein kinase A, mitogen-activated protein kinase, and p21-activated kinase were also altered in the mutants, suggesting that Rho GTPases might function upstream of these kinases. This study highlights the important role of Rho GTPases in A. oligospora and provides insights into the regulatory mechanism of signaling pathways in trap morphogenesis and lifestyle transition of NT fungi. Overall design: To obtain real-time information, we used RNA-seq technology to sequence the transcriptome profiles between A. oligospora and nematode C. elegans at different time points (0 h, 12 h, 24 h, 36 h, and 48 h). After sequencing a mixed sample (A. oligospora and C. elegans), fungal reads were extracted by searching the RNA-seq reads in the A. oligospora genome.