The AoMYB-like–AoAreB–AoAspB module links nitrogen availability to conidiation in Arthrobotrys oligospora
Year: 2026
Type: article
Abstract: Nitrogen availability is an important environmental cue that influences fungal growth and developmental differentiation, yet the transcriptional mechanisms linking nitrogen status to conidiation remain poorly understood in nematode-trapping fungi. Here, we investigated the molecular mechanism underlying nitrogen-responsive conidiation in the nematode-trapping fungus Arthrobotrys oligospora . Increasing nitrogen availability promoted conidial production and was accompanied by increased expression of AoareB . Deletion of AoareB caused severe defects in hyphal development and conidiation, characterized by increased hyphal septation, reduced nuclear numbers, and decreased conidiophore and conidial production. The Δ AoareB mutant exhibited markedly reduced mycelial growth and conidiation under ammonium sulfate, glutamine, or glutamate supplementation, indicating that AoAreB contributes to nitrogen-dependent developmental responses. Mechanistically, AoAreB directly bound the promoter of the conidiation-related gene AoaspB and activated its transcription. Furtherly, AoMcm1 physically interacts with AoAreB and potentiates AoAreB-mediated transcriptional activation of AoaspB , revealing an additional layer of transcriptional co-regulation. At the upstream regulatory tier, an MYB-like transcription factor activated AoareB expression, establishing an AoMYB-like–AoAreB–AoAspB regulatory module. Functional analyses further demonstrated that AoMYB-like and AoAspB contribute to conidiation under nitrogen-supplemented conditions, particularly in the presence of ammonium sulfate, glutamine, or glutamate. This study identified an AoMYB-like–AoAreB–AoAspB regulatory module that links nitrogen availability to conidiation in A. oligospora and elucidated its molecular role in regulating nitrogen-dependent conidiation. These findings provide new insights into nitrogen-responsive developmental regulation in nematode-trapping fungi and advance the understanding of the molecular mechanisms underlying nitrogen-dependent fungal development.
Source: BMC Microbiology
Institution: Yunnan University
Language: English
Subfield: Molecular Biology
Domain: Life Sciences
SDG: Zero hunger
Open Access status: gold
Estimated APC paid: $2,990
OpenAlex ID: W7225468401