Functional characterization of FaMBL1, a G-type lectin gene family member, in response to fungal pathogens of strawberry

Fragaria × ananassa mannose-binding lectin gene, FaMBL1, is a member of strawberry G-type lectin family involved in strawberry defense. Genome-wide identification of G-type lectin gene family was carried out in F. vesca, where 133 G-lectin genes were found. Their expression profile was retrieved from available databases showing that many G-lectin genes are actively expressed during strawberry development or interaction with pathogens. Hence, stable transgenic strawberry plants overexpressing the FaMBL1 gene were generated to better investigate the role of this gene in defense. Transformed strawberry plants were selected and evaluated for their disease-related phytohormones content and reaction to biotic stresses revealing that jasmonic acid (JA) content decreased in overexpressing lines compared to wild type (WT). Petioles of overexpressing lines inoculated with C. fioriniae had lower disease incidence than WT, and leaves of overexpressing lines challenged by B. cinerea showed remarkably smaller lesion diameters compared to WT and higher chitinase 2-1 (FaChi2-1) gene expression. Our results indicate that FaMBL1 gene plays an important role in strawberry response to fungal diseases caused by C. fioriniae and B. cinerea.