Research
| Title： | Ras subfamily GTPases regulate development, aflatoxin biosynthesis and pathogenicity in the fungus Aspergillus flavus |
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| First author： | Zhu, Zhuo; Ma, Gengli; Yang, Mingkun; Tan, Can; Yang, Guang; Wang, Sen; Li, Na; Ge, Feng; Wang, Shihua |
| Journal： | ENVIRONMENTAL MICROBIOLOGY |
| Years： | 2021 |
| DOI： | 10.1111/1462-2920.15626 |
| Abstract： | Ras subfamily proteins are molecular switches in signal transduction pathways of many eukaryotes that regulate a variety of cellular processes. Here, the Ras subfamily, encoded by six genes, was identified in Aspergillus flavus: rasA, rasB, rasC, rab-33, rheb and rsr1. The rsr1 deletion mutant ( increment rsr1), rheb deletion mutant ( increment rheb) and double deletion mutant ( increment rheb/rsr1) displayed significantly decreased growth and sporulation. Sclerotia formation was significantly decreased for increment rheb or increment rheb/rsr1 but increased for increment rsr1. Aflatoxin production was significantly increased in increment rheb but decreased in increment rsr1 and increment rheb/rsr1. We found that rsr1 and rheb are crucial for the pathogenicity of A. flavus. Quantitative proteomics identified 520 differentially expressed proteins (DEPs) for the increment rsr1 mutant and 133 DEPs for the increment rheb mutant. These DEPs were annotated in multiple biological processes and KEGG pathways in A. flavus. Importantly, we identified the cytokinesis protein SepA in the protein-protein interaction network of rsr1, and deletion mutants showed that SepA has pleiotropic effects on growth and AF biosynthesis, which may depend on Rsr1 for regulation in A. flavus. Our results indicated that these Ras subfamily proteins exhibited functional redundancy with each other but there were also differences in A. flavus. |
