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

Abstract

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).

Peroxins in Peroxisomal Receptor Export System Contribute to Development, Stress Response, and Virulence of Insect Pathogenic Fungus Beauveria bassiana

“…The three peroxins in the receptor export complex significantly participate in fungal resistance to oxidative stress, which is identical to the roles of BbPex5 and BbPex7 [ 11 ]. Similar results were also observed in other filamentous fungi (e.g., A. oligospora and F. graminearum ) [ 15 , 16 ]. In Metarhizium robertsii (a sister entomopathogenic fungus), peroxisomal activity and peroxin genes are involved in fungal responses to oxidative stress [ 38 ].…”

“…As expected, these three peroxins were localized in peroxisomes, but dispensable for the biogenesis of peroxisomes, which is similar to the roles of Pex5 and Pex7 in B. bassiana [ 11 ]. However, ablation of Pex1 and Pex6 resulted in almost no detectable peroxisomes in A. oligospora [ 15 ]. In Chinese hamster ovary cells, Pex26 contributes to formation of peroxisomes [ 27 ].…”

“…In fungi, fatty acids are mainly degraded in peroxisomes. Pex1 and Pex6 contribute to the conserved role of peroxisomes in fatty-acid degradation [ 15 , 18 ]. However, BbPex5 is necessary for fatty-acid assimilation, but BbPex7 is not [ 11 ].…”

“…In addition to their biochemical roles in receptor recycling, these components of the docking complex play various biological roles in filamentous fungi. In Arthrobotrys oligospora (a nematode-trapping fungus), Pex1 and Pex6 are involved in fatty-acid utilization, vegetative growth, conidiation, stress response, and pathogenicity [ 15 ]. In Fusarium graminearum (a plant pathogen), Pex1 plays an additional role in maintaining cell-wall integrity [ 16 ].…”

The Arf-GAP Proteins AoGcs1 and AoGts1 Regulate Mycelial Development, Endocytosis, and Pathogenicity in Arthrobotrys oligospora

“…Oat medium was used to grow Caenorhabditis elegans (strain N2) at 26 °C in the dark for a week. PDA, tryptone glucose (TG), and tryptone yeast extract glucose agar (TYGA) were used for the phenotypic analysis as previously described [ 37 ] and corn-maizena yeast extract (CMY) was used for sporulation as previously described [ 38 ].…”