Autophagy is a conserved intracellular recycling mechanism, in which autophagy-related genes 12 and 16 (ATG12 and ATG16) function in a complex controlling the ubiquitin-like conjugation system. In the insect-pathogenic fungus Beauveria bassiana, ATG12 and ATG16 were functionally characterized. Disruption of BbATG12 or BbATG16 resulted in the absence of autophagic bodies under starvation stress. ΔBbATG12 and ΔBbATG16 mutant strains displayed similar defects in asexual development (conidiation and blastospore formation) and tolerance to oxidative stress. ΔBbATG16 strain exhibited the impaired growth on the media with gelatin or chitin as a single nitrogen source, and ΔBbATG12 displayed decreased growth on the media with sucrose, fructose or maltose as a single carbon source. Both BbATG12 and BbATG16 were required for fungal virulence. BbATG16 mutation had more effects on fungal virulence than BbATG12 in topical infection assay, although both genes had similar contributions to fungal virulence in intrahemocoel injection assay. This study indicates that BbATG12 and BbATG16 mediate diverse biological functions in addition to their convergent roles in autophagy.

中文翻译：

---

自噬相关基因在球孢白僵菌分生孢子发生和芽孢形成、毒力和应激反应中的作用

自噬是一种保守的细胞内循环机制，其中自噬相关基因 12 和 16（ATG12 和 ATG16）在控制泛素样结合系统的复合物中起作用。在昆虫病原真菌白僵菌中，对 ATG12 和 ATG16 进行了功能表征。BbATG12 或 BbATG16 的破坏导致饥饿应激下自噬体的缺失。ΔBbATG12 和 ΔBbATG16 突变株在无性发育（分生孢子和胚泡形成）和氧化应激耐受性方面表现出类似的缺陷。ΔBbATG16 菌株在以明胶或几丁质为单一氮源的培养基上生长减弱，而 ΔBbATG12 在以蔗糖、果糖或麦芽糖为单一碳源的培养基上生长减弱。BbATG12 和 BbATG16 都是真菌毒力所必需的。在局部感染试验中，BbATG16 突变对真菌毒力的影响大于 BbATG12，尽管这两种基因在血腔内注射试验中对真菌毒力的贡献相似。这项研究表明，BbATG12 和 BbATG16 除了它们在自噬中的趋同作用外，还介导了多种生物学功能。