The Development of Aspergillus flavus and Biosynthesis of Aflatoxin B1 are Regulated by the Golgi-Localized Mn²⁺ Transporter Pmr1

Abstract

Microorganisms rely on diverse ion transport and trace elements to sustain growth, development, and secondary metabolism. Manganese (Mn 2+ ) is essential for various biological processes and plays a crucial role in the metabolism of human cells, plants, and yeast. In Aspergillus flavus, we confirmed that Pmr1 localized in cis-and medial-Golgi compartments was critical in facilitating Mn 2+ transport, fungal growth, development, secondary metabolism, and glycosylation. In comparison to the wild type, the Δpmr1 mutant displayed heightened sensitivity to environmental stress, accompanied by inhibited synthesis of aflatoxin B1, kojic acid, and a substantial reduction in pathogenicity toward peanuts and maize. Interestingly, the addition of exogenous Mn 2+ effectively rectified the developmental and secondary metabolic defects in the Δpmr1 mutant. However, Mn 2+ supplement failed to restore the growth and development of the Δpmr1Δgdt1 double mutant, which indicated that the Gdt1 compensated for the functional deficiency of pmr1. In addition, our results showed that pmr1 knockout leads to an upregulation of O-glycosyl-Nacetylglucose (O-GlcNAc) and O-GlcNAc transferase (OGT), while Mn 2+ supplementation can restore the glycosylation in A. flavus. Collectively, this study indicates that the pmr1 regulates Mn 2+ via Golgi and maintains growth and metabolism functions of A. flavus through regulation of the glycosylation.

Peanut Rhizosphere Achromobacter xylosoxidans Inhibits Aspergillus flavus Development and Aflatoxin Synthesis by Inducing Apoptosis through Targeting the Cell Membrane

“…A modified method from previous study was employed to quantify AFB1 production. Briefly, 2 × 10 6 spores was inoculated into 20 mL of potato dextrose broth (PDB) medium supplemented with ZAS at varying concentrations (0, 1/2 MIC, and MIC).…”

Detoxification of Aflatoxin B1 by Phytochemicals in Agriculture and Food Science

“…As the most toxic mycotoxin in the world, AFB 1 has toxic effects such as acute hepatotoxicity, immunosuppression, mutagenicity, teratogenesis, and carcinogenesis, becoming one of the main causes of liver cancer. Therefore, AFB 1 is classified as a group I carcinogen by the International Agency for Research on Cancer. − Moreover, it is highly susceptible to exposure in daily plant-derived and animal-derived foods, leading to oxidative damage and genotoxic effects on various organs, such as the liver, kidney, and reproductive system in humans, livestock, and poultry (Figure B). − It cannot be ignored that livestock and poultry feeds are the hardest hit area for AFB 1 exposure. AFB 1 can lead to anorexia and vomiting in livestock and poultry and disrupt intestinal structure and immune function, , which will seriously reduce the hatchability, newborn weight, growth rate, production, and quality of animal-derived food, as well as disease vaccination efficiency, and inhibit the feed conversion rate, thereby severely hitting the agriculture and animal husbandry industry .…”