Genome‐Wide Characterization of SnRK Gene Family in Mangrove Plant Avicennia marina and Function of AmSnRK2.7‐AmENO2 Module in Response to Salinity

ABSTRACT Sucrose non‐fermenting‐1‐related protein kinase (SnRK) is a plant serine/threonine kinase that mediates stress signaling, yet its function in the mangrove Avicennia marina remains unexplored. In this study, we identified 46 SnRK genes in A. marina , classifying them into three subfamilies with high phylogenetic conservation. Family expansion occurred mainly through 20 segmental duplication events under purifying selection ( Ka / Ks < 1). Promoter regions were enriched in stress‐ and hormone‐responsive elements, and expression profiling showed distinct tissue‐specific and stress‐responsive patterns. Our study specifically focused on the functional characterization of AmSnRK2.7 . AmSnRK2.7 ‐overexpressed Arabidopsis thaliana increases salt tolerance by altering the expression of ion transport genes and mediating Na + efflux from the roots. Further investigation revealed that AmSnRK2.7 interacts with and phosphorylates AmENO2 (enolase, a key enzyme in the glycolysis pathway). Meanwhile, measurements of ATP content in wild type, AmSnRK2.7 ‐overexpressed Arabidopsis lines and the atsnrk2.6 (homologous gene of AmSnRK2.7 in A. thaliana ) mutant confirm that the AmSnRK2.7‐AmENO2 module can affect the energy‐driven Na + efflux. Our findings provide key insights into the role of SnRK gene family in mangrove adaptation to saline intertidal habitat, and suggest AmSnRK2.7‐AmENO2 module plays a role in salt tolerance.