Functional analysis of three glucoside hydrolase family 1 genes revealed their positive regulatory roles in the release of bonded-state aroma from strawberry fruits

Abstract

The release of glycosidically-bound volatiles is crucial for strawberry aroma, but how this process is regulated by environmental factors and specific genes remains poorly characterized. We monitored β-glucosidase activity during fruit ripening in 'Benihoppe' strawberry, conducted a genome-wide identification of the FaGH1 family, and used transcriptome data from fruits subjected to weak-light and low-temperature stress to identify candidate genes. The function of key candidates was preliminarily tested via prokaryotic expression and transient overexpression/silencing in fruit. We identified 92 FaGH1 genes and shortlisted three (FaBGLU40, FaBGLU42, and Fasfr2) as responsive to environmental stress. Transient manipulation of these genes altered the profile of volatile aroma compounds, and promoter analysis revealed stress-related cis-elements. Our results provide initial evidence that specific FaGH1 genes are involved in the environmental regulation of strawberry aroma. This study establishes a foundation for future work, where stable genetic transformation and more detailed molecular analyses will be essential to confirm these proposed functions and their application in breeding.

Keywords: Bonded aroma; FaGH1s family; Strawberry; Stress response; β-Glucosidase.