Regulation of Conidiogenesis in Aspergillus flavus

Abstract

Aspergillus flavus is a representative fungal species in the Aspergillus section Flavi and has been used as a model system to gain insights into fungal development and toxin production. A. flavus has several adverse effects on humans, including the production of the most carcinogenic mycotoxin aflatoxins and causing aspergillosis in immune-compromised patients. In addition, A. flavus infection of crops results in economic losses due to yield loss and aflatoxin contamination. A. flavus is a saprophytic fungus that disperses in the ecosystem mainly by producing asexual spores (conidia), which also provide long-term survival in the harsh environmental conditions. Conidia are composed of the rodlet layer, cell wall, and melanin and are produced from an asexual specialized structure called the conidiophore. The production of conidiophores is tightly regulated by various regulators, including the central regulatory cascade composed of BrlA-AbaA-WetA, the fungi-specific velvet regulators, upstream regulators, and developmental repressors. In this review, we summarize the findings of a series of recent studies related to asexual development in A. flavus and provide insights for a better understanding of other fungal species in the section Flavi.

Histone 2-Hydroxyisobutyryltransferase Encoded by Afngg1 Is Involved in Pathogenicity and Aflatoxin Biosynthesis in Aspergillus flavus

“…Expression of A. flavus conidiogenesis genes is regulated by a cascade involving brlA , abaA and wetA [ 20 ]. BrlA and abaA are key transcription factors, of which brlA initiates conidia formation, and abaA contributes to conidia development and also affects sclerotia formation and AFB 1 production [ 21 , 22 ]. StuA affects the expression of downstream genes by influencing brlA and abaA , and regulates sporulation [ 23 ].…”

Detection of Maize Mold Based on a Nanocomposite Colorimetric Sensor Array under Different Substrates

“…2 Mold contamination not only reduces the nutritional value and appearance of the maize but also produces harmful secondary metabolites. 3 Aspergillus flavus, a major mold species affecting maize, can penetrate the maize shell 4 and produce various complex and stable toxins. 5 These toxins make the disinfection process extremely challenging, resulting in substantial economic losses and a loss of personal health.…”

A Simple CRISPR/Cas9 System for Efficiently Targeting Genes of Aspergillus Section Flavi Species, Aspergillus nidulans, Aspergillus fumigatus, Aspergillus terreus, and Aspergillus niger

“…The S-type isolates produce many small sclerotia but conidiate poorly, whereas the L-type isolates produce few, large sclerotia or none but abundant conidia on most agar media ( 4 ). Extensive studies on aflatoxin production and asexual development have been conducted ( 3 , 5 , 6 ).…”