Elucidating the role of Alg14 in governing cell wall architecture and biological functions in the entomopathogenic fungus Beauveria bassiana

Entomopathogenic fungus Beauveria bassiana is widely utilized in agricultural pest control, with its efficacy largely dependent on the precise architecture of the cell wall. The fungal cell wall is composed of diverse glycoproteins and polysaccharides, the synthesis of which is typically initiated by UDP-acetylglucosamine transferase, a complex comprising Alg14 and Alg13. However, the biochemical and physiological functions of Alg14 in entomopathogenic fungi have been barely explored. In this study, we identified and characterized a novel Alg14 homologue in B. bassiana , which was demonstrated with the localization to the endoplasmic reticulum and interaction with Alg13. Deletion of Alg14 transcriptionally impacted on pathways of amino sugar metabolism and N -glycan biosynthesis in B. bassiana . Consequently, Δ Alg14 showed 55 % and 11 % reduction in N - and O -glycosylation in cell wall proteins, respectively, as well as significant decreases in chitin and glycans. These changes compromised cell wall integrity and reduced fungal tolerance to cell wall stress. Beyond its role in cell wall architecture, Alg14 also negatively regulated energy metabolism, referring to NADH/NAD + ratio and ATP production, thereby affecting fungal development and morphological transitions. Agl14 further impacted the quality, antioxidant capacity, and virulence of B. bassiana spores. Both transcriptomic and experimental analyses revealed an Alg14 -modulated glycosylation network that is essential for fungal physiology. This study provides novel insights into the multifaceted role of Alg14 in B. bassiana and offers a theoretical foundation for engineering strategies aimed at maintaining and/or enhancing the efficacy of biopesticides for practical agricultural applications.