Vacuole Proteins with Optimized Microtubule Assembly Is Required for Fum1 Protein Localization and Fumonisin Biosynthesis in Mycotoxigenic Fungus Fusarium verticillioides

Abstract

Fumonisin contamination of corn caused by Fusarium verticillioides is a major concern worldwide. While key genes involved in fumonisin biosynthesis are known, the location within the fungal cell where this process occurs has yet to be fully characterized. In this study, three key enzymes, i.e., Fum1, Fum8, and Fum6, associated with early steps of fumonisin biosynthesis pathway, were tagged with GFP, and we examined their cellular localization. Results showed that these three proteins co-localized with the vacuole. To further understand the role of the vacuole in fumonisin B1 (FB1) biosynthesis, we disrupted two predicted vacuole associated proteins, FvRab7 and FvVam7, resulting in a significant reduction of FB1 biosynthesis and a lack of Fum1-GFP fluorescence signal. Furthermore, we used the microtubule-targeting drug carbendazim to show that proper microtubule assembly is critical for proper Fum1 protein localization and FB1 biosynthesis. Additionally, we found that α1 tubulin is a negative regulator in FB1 biosynthesis. We concluded that vacuole proteins with optimized microtubule assembly play a crucial role in proper Fum1 protein localization and fumonisin production in F. verticillioides.

Characterization of Fusarium verticillioides Med1 LxxLL Motif Involved in Fumonisin Biosynthesis

“…Our recent study demonstrated the crucial role of vacuoles as an important intracellular organelle in FB 1 biosynthesis [39]. We hypothesized that deletion of Med1 may alter vacuolar morphology, thereby leading to enhanced FB 1 biosynthesis.…”

“…organelle in FB1 biosynthesis [39]. We hypothesized that deletion of Med1 may alter vacuolar morphology, thereby leading to enhanced FB1 biosynthesis.…”

Development of an Efficient CRISPR/Cas9 System in Fusarium verticillioides and Its Application in Reducing Mycotoxin Contamination

“…An efficient and stable genetic transformation system has been developed, including Agrobacterium -mediated transformation (ATMT) and PEG-mediated protoplast transformation . These systems enable the introduction of desired genetic modifications into the fungal genome, including gene knockouts and gene replacements . However, the generation of mutants in F.…”