Quantitative Proteomic Analysis for High- and Low-Aflatoxin-Yield Aspergillus flavus Strains Isolated From Natural Environments

Abstract

The molecular mechanisms underlying aflatoxin production have been well-studied in strains of the fungus Aspergillus flavus (A. flavus) under artificial conditions. However, aflatoxin biosynthesis has rarely been studied in A. flavus strains isolated from field conditions with different aflatoxin-producing ability. In the present study, tandem mass tag (TMT) labeling and high-performance liquid chromatography (HPLC) coupled with tandem-mass spectrometry analysis were used for proteomic quantification in natural isolates of high- and low-aflatoxin-yield A. flavus strains. Additionally, findings obtained using the TMT-labeling method were validated using the high-resolution multiple reaction monitoring (MRM-HR) method. In total, 4,363 proteins were quantified, among which 1,045 proteins were differentially expressed between the high- and low-aflatoxin-yield A. flavus strains. Bioinformatics analysis showed that the up-regulated proteins were significantly enriched in carbon-related metabolism and the biosynthesis of secondary metabolites, whereas the down-regulated proteins were enriched in oxidative phosphorylation. Moreover, GST proteins were found to be significantly down-regulated in high-yield A. flavus strains; this result contradicted previous findings obtained from A. flavus strains grown under artificial conditions. In summary, our study provides novel insights into aflatoxin regulation in A. flavus under field conditions and could facilitate the development of various strategies for the effective control of aflatoxin contamination in food crops.

Lysine Succinylation of VBS Contributes to Sclerotia Development and Aflatoxin Biosynthesis in Aspergillus flavus

“…Thus, we perform a TMT-labeled quantitative lysine succinylome to comprehensively report the changes in Ksuc levels between high and low AF production strains of A. flavus isolated under natural conditions. From our quantitative global proteomics data, we noticed that the upregulated proteins in the high AF yield group were mostly enriched in carbon-related metabolism, whereas the downregulated proteins were enriched in oxidative phosphorylation; through subsequent functional analysis, we found that the upregulated proteins involved in carbon-related metabolism had a direct relationship with AF production ( 48 ).…”

“…In this study, all protein samples were obtained from our previous global proteomics protein preparation and prepared from a single experiment ( 48 ). In detail, 10 6 conidia was inoculated into liquid YES media and shaken at 180 revolutions/min for 5 days at 28 °C.…”

Protein biomarker for early diagnosis of microbial toxin contamination: Using Aspergillus flavus as an example

“…The production of aflatoxins in food is a gradual process, so early diagnosis before aflatoxin production is crucial to effectively prevent their formation and spread. Researchers have explored various methods for achieving early detection of aflatoxin contamination, such as diagnosing the risk of aflatoxin contamination by measuring the expression of biomarkers (genes, metabolites, or proteins) associated with aflatoxin production (Baquiao et al., 2016; Li et al., 2021; Wang et al., 2022; Xie et al., 2022), as well as establishing warning models based on specific indicators (such as temperature, humidity, pH, etc.) in historical monitoring data to predict the risk of toxin production (Hu et al., 2013; Temba et al., 2021).…”