Aoatg11 and Aoatg33 are indispensable for mitophagy, and contribute to conidiation, the stress response, and pathogenicity in the nematode-trapping fungus Arthrobotrys oligospora

SNARE Protein AoSec22 Orchestrates Mycelial Growth, Vacuole Assembly, Trap Formation, Stress Response, and Secondary Metabolism in Arthrobotrys oligospora

“…The spore yield of each strain was measured from the 15-day-old cultures grown on corn meal yeast extract (CMY) medium, as previously described [ 44 , 45 ]. Freshly harvested conidia and hyphae of WT and mutant strains were stained with 20 μg/mL of cell wall-specific calcofluor white (CFW, Sigma-Aldrich, St. Louis, MO, USA) or nucleus-specific 4′,6-diamidino-2-phenylindole (DAPI, Sigma-Aldrich, USA), and visualized for hyphal morphology under an inverted fluorescence microscope [ 46 , 47 ].…”

“…Then, 400 nematodes were introduced to each plate for the induction of trap formation, followed by microscopic observation of trap formation and nematode predation at a 12 h interval [ 45 ]. The traps were stained with 20 μg/mL CFW and visualized as aforementioned [ 47 ].…”

AoSte12 Is Required for Mycelial Development, Conidiation, Trap Morphogenesis, and Secondary Metabolism by Regulating Hyphal Fusion in Nematode-Trapping Fungus Arthrobotrys oligospora

“…Nematode-trapping (NT) fungi are a special ecological group that can use their own specialized structures (traps) to capture nematodes that move freely in the soil. Most NT fungi can live both saprophytically on organic matter and, as predators, by capturing tiny animals ( 1 – 3 ). NT fungi change their saprophytic lifestyle to a predacious lifestyle by producing traps, so traps are not only the weapons that NT fungi use to attack nematodes but are also an important indicator of their lifestyle transition ( 4 , 5 ).…”

“… Arthrobotrys oligospora is a typical NT fungus that produces an adhesive three-dimensional network, and it is often used as a potential model for studying the interactions between fungi and nematodes ( 8 , 9 ). In recent years, multiple signaling pathways and cellular processes, including the mitogen-activated protein kinase (MAPK) ( 7 , 10 ), G protein signaling ( 11 – 13 ), small GTPases ( 14 , 15 ), autophagy ( 2 , 16 ), and peroxisome ( 17 ) have been shown to involve in mycelial development and trap formation of NT fungus in A. oligospora .…”

Peroxin Pex14/17 Is Required for Trap Formation, and Plays Pleiotropic Roles in Mycelial Development, Stress Response, and Secondary Metabolism in Arthrobotrys oligospora

“…Subsequently, cytochemical staining showed that EDs contained catalase and d -amino acid oxidase, thus EDs were considered as peroxisomal in nature ( 26 ). Recently, increasing numbers of studies have suggested that heterotrimeric G-proteins (G-protein) and related signals play an indispensable role in asexual development and lifestyle transition ( 25 ), and several autophagy-related genes are also involved in the trap formation of A. oligospora , such as ATG5 ( 27 ), and ATG11 ( 28 ). Recently, two PEX genes, PEX1 and PEX6 , encoding an AAA-type ATPase, were identified in A. oligospora , and the absence of traps, conidia, and peroxisomes was caused by the loss of PEX1 and PEX6 ( 29 ).…”