A putative F‐box‐domain‐encoding gene AOL_s00076g207 regulates the development and pathogenicity of Arthrobotrys oligospora

Abstract

F-box protein is a key component of the Skp1-cullin-F-box-type ubiquitin ligase complex (SCF-ULC) that marks its target proteins with ubiquitin for proteasomal degradation. In this study, we explored the potential role of AOL_s00076g207 (Aog207) in Arthrobotrys oligospora, a model fungus for studying nematodes-fungi interactions. The Aog207 gene encodes a putative F-box protein of the SCF-ULC. Deletion of Aog207 could inhibit mycelial growth in TYGA and PDA media. More importantly, the conidial germination rate of ΔAog207 mutants was remarkably declined compared to that of wildtype (WT) strain, and the mutant strains were more sensitive toward chemical stressors than the WT strain. In addition, ΔAog207 mutants generated fewer traps and captured fewer nematodes than WT strain. In summary, Aog207 disruption significantly affected the pathogenicity, mycelial growth, conidial germination, environmental adaptation and trap formation of A. oligospora.These findings may facilitate a better understanding of the nematode predation mechanism of A. oligospora and provide an experimental basis for developing biological control agents against nematodes.

Roles of the Fungal-Specific Lysine Biosynthetic Pathway in the Nematode-Trapping Fungus Arthrobotrys oligospora Identified through Metabolomics Analyses

“…Caenorhabditis elegans , which was stored in our laboratory, was cultured in NGM medium (3 g/L NaCl, 2.5 g/L peptone, 17 g/L agar, 5 mg/L cholesterol-ethanol solution, 1 mM MgSO 4 , 1 mM CaCl 2 , and 12.5 mM KH 2 PO 4 -K 2 HPO 4 solution) containing Escherichia coli OP50 for 7 d at 20 °C. Caenorhabditis elegans were collected by washing NGM plates with M9 buffer solution (22 mM KH 2 PO 4 , 42 mM Na 2 HPO 4 , 85.5 mM NaCl, and 1 mM MgSO 4 ) [ 21 ]. The plasmids pUC19 and pUC57–hygR were maintained in E. coli DH5α.…”

“…The construction of the Aoaar disruption vector was undertaken using similar methods as in our previous report [ 21 ]. Genomic DNA was extracted using a fungal DNA extraction kit (Solarbio, Beijing, China).…”

“…The transformation of protoplasts was according to our previously described methods [ 21 , 24 ]. The knockout DNA fragment was amplified from the knockout plasmid using the Aoaar -5F and Aoaar -3R primer pair.…”

“…Approximately 2 × 10 3 conidia of the WT and Δ Aoaar mutant strains were spread on WA medium and germinated at 28 °C for 72 h. Subsequently, approximately 500 C. elegans nematodes were added to the middle of each plate to induce trap formation. The numbers of traps induced and nematodes captured were counted under a light microscope every six hours for 24 h [ 7 , 20 , 21 ].…”

Recent Advances in Life History Transition with Nematode-Trapping Fungus Arthrobotrys oligospora and Its Application in Sustainable Agriculture

“…In addition, mutations in latg13 , atg1 , atg4 , and atg5 led to the loss of ability for trap formation in A. oligospora [ 77 , 78 , 79 , 80 ]. Besides autophagy, some cellular processes affect the formation of traps in A. oligospora , such as woronin body synthesis [ 81 ], RNA interference [ 82 ], glycerol biosynthesis [ 83 ], production of reactive oxygen species [ 84 ], F-box protein synthesis [ 85 ], nitrate assimilation pathway [ 86 ], pH-sensing receptor protein synthesis [ 87 ], velvet family protein synthesis [ 88 ], scaffold protein synthesis [ 89 ], lectin synthesis [ 90 ], actin synthesis [ 91 ], and malate synthase [ 92 ]. Finally, research confirms that A. oligospora possesses pathways related to the biosynthesis of SECs of the gene cluster AOL_s00215g, containing 11 genes.…”