Analysis of Ubr1-mediated germination and polar growth of Beauveria bassiana based on the combination of transcriptome and proteome

Abstract:

[Objective] To clarify the mechanism of Ubr1 affecting the polar growth of Beauveria bassiana based on the differentially expressed genes (DEGs) and proteins (DEPs) and their pathways in the conidia of the wild-type (WT) and ubr1-deleted (Δubr1) strains at the same time point and thus to lay a theoretical basis for improving potential of B. bassiana for biocontrol. [Methods] Through KEGG analysis of the transcriptome and proteome, the pathways of the DEGs and DEPs were clarified. The germinated conidia in each germination medium (GM)-derived plate were photographed with a microscope to verify the influence of the differential pathways on polar growth of the conidia.[Results] ubr1 deletion impaired the germination of conidia, resulting in abnormally curved or hook-shaped germ tubes. Both the DEGs and DEPs were involved in nitrogen metabolism, arginine and proline metabolism, and ether ester metabolism. Further verification showed that abnormal arginine metabolism caused by ubr1 deletion was an important reason for the disorder of conidial polar growth and that abnormal metabolism of galactose and nitrogen led to slow germination of conidia. [Conclusion]The absence of ubr1 blocks arginine metabolism, resulting in abnormal polar growth of germ tube. The abnormal metabolism of galactose and nitrogen also delays the germination of conidia. The findings are expected to enhance the understanding of the mechanism of polar growth and the penetration process in the infection cycle of filamentous fungi.