AoPEX1 and AoPEX6 Are Required for Mycelial Growth, Conidiation, Stress Response, Fatty Acid Utilization, and Trap Formation in Arthrobotrys oligospora

• Published in: Microbiology spectrum Vol. 10; no. 2; p. e0027522
• Main Authors: Liu, Qianqian, Li, Dongni, Jiang, Kexin, Zhang, Ke-Qin, Yang, Jinkui
• Format: Journal Article
• Language: English
• Published: United States American Society for Microbiology 27.04.2022
• Subjects: Animals; Arthrobotrys oligospora; Ascomycota - physiology; conidiation; fatty acid utilization; Fatty Acids - metabolism; Host-Microbial Interactions; Nematoda - microbiology; peroxisome biogenesis-genes; Research Article; Spores, Fungal - genetics; transcriptome analysis; trap formation; trap formation; fatty acid utilization; transcriptome analysis; Arthrobotrys oligospora; conidiation; peroxisome biogenesis-genes
• ISSN: 2165-0497; 2165-0497
• DOI: 10.1128/spectrum.00275-22

( ) is a typical nematode-trapping (NT) fungus that can capture nematodes by producing adhesive networks. Peroxisomes are single membrane-bound organelles that perform multiple physiological functions in filamentous fungi. Peroxisome biogenesis proteins are encoded by genes, and the functions of genes in and other NT fungi remain largely unknown. Here, our results demonstrated that two genes ( and ) are essential for mycelial growth, conidiation, fatty acid utilization, stress tolerance, and pathogenicity in . and knockout resulted in a failure to produce traps, conidia, peroxisomes, and Woronin bodies and damaged cell walls, reduced autophagosome levels, and increased lipid droplet size. Transcriptome data analysis showed that and deletion resulted in the upregulation of the proteasome, membranes, ribosomes, DNA replication, and cell cycle functions, and the downregulation of MAPK signaling and nitrogen metabolism. In summary, our results provide novel insights into the functions of genes in the growth, development, and pathogenicity of and contribute to the elucidation of the regulatory mechanism of peroxisomes in trap formation and lifestyle switching in NT fungi. Nematode-trapping (NT) fungi are important resources for the biological control of plant-parasitic nematodes. They are widely distributed in various ecological environments and capture nematodes by producing unique predatory organs (traps). However, the molecular mechanisms of trap formation and lifestyle switching in NT fungi are still unclear. Here, we provided experimental evidence that the and genes could regulate mycelial growth and development, trap formation, and nematode predation of . We further analyzed the global transcription level changes of wild-type and mutant strains using RNA-seq. This study highlights the important role of peroxisome biogenesis genes in vegetative growth, conidiation, trap formation, and pathogenicity, which contribute to probing the mechanism of organelle development and trap formation of NT fungi and lays a foundation for developing high-efficiency nematode biocontrol agents.