Characterization of GALA (α-galactosidase) gene family and studying its response to elevated CO2 in Lycium barbarum

Abstract

Elevated CO2 affects the fruit quality of goji berries, particularly sugars and polysaccharides contents, by regulating genes involved in sugar metabolism. GALA (α-galactosidase) is essential in regulating carbohydrate partitioning and fruit sugars. Little information is available on the regulatory functions of GALA and its response to climate change in goji berries. The study aimed to identify, analyze, characterize, and validate the GALA gene family of goji berries and their role in sugar metabolism. Subcellular localization and bimolecular fluorescence analysis revealed that LbGALA1-LbGALA4 (LbGALA1, LbGALA2, LbGALA3, and LbGALA4) are found in the plasma membrane and cytoplasm, and LbGALA1 and LbGALA3 protein interactions. Phylogenetic analysis clustered all seven identified LbGALA genes into a single group, which may have acquired specialized functions during evolution. A significant correlation between LbGALA expression and galactose in goji berries and an increase in fruit sugars in T1 transgenic tomato by overexpressing LbGALA1-LbGALA4 under elevated CO2 levels confirm their primary role and response to elevated CO2 in sugar metabolism. This study provides novel information on the LbGALA gene family and demonstrates their regulatory role in sugar accumulation and CO2 response. The data will be helpful in screening and breeding goji berry cultivars and similar species with high sugar content, as well as providing a new perspective on plant response to climate change.