Analysis of Methylesterase Gene Family in Fragaria vesca Unveils Novel Insights into the Role of FvMES2 in Methyl Salicylate-Mediated Resistance against Strawberry Gray Mold

Methylesterases (MESs) hydrolyze
carboxylic ester and are important
for plant metabolism and defense. However, the understanding of MES’
role in strawberries against pathogens remains limited. This study
identified 15 FvMESs with a conserved catalytic triad from the Fragaria vesca genome. Spatiotemporal expression
data demonstrated the upregulated expression of FvMESs in roots and developing fruits, suggesting growth involvement. The FvMES promoter regions harbored numerous stress-related cis-acting elements and transcription factors associated
with plant defense mechanisms. Moreover, FvMES2 exhibited
a significant response to Botrytis cinerea stress and showed a remarkable correlation with the salicylic acid
(SA) signaling pathway. Molecular docking showed an efficient binding
potential between FvMES2 and methyl salicylate (MeSA). The role of
FvMES2 in MeSA demethylation to produce SA was further confirmed through in vitro and in vivo assays. After MeSA
was applied, the transient overexpression of FvMES2 in strawberries enhanced their resistance to B.
cinerea compared to wild-type plants.