Genome-Wide Identification of the LEA Gene Family in Myricaria laxiflora and Its Responses to Abiotic Stress

Background: The late embryogenesis abundant (LEA) gene family plays a critical role in abiotic stress tolerance during plant growth and development. Myricaria laxiflora, as a key pioneer species in the extreme hydrological fluctuation zone of the Yangtze River, has evolved unique adaptation mechanisms potentially linked to gene family evolution. However, the molecular mechanisms underlying how the LEA gene family responds to alternating flooding–drought cycles remain unclear. Methods and Results: In this study, we identified 31 LEA genes through whole-genome and transcriptome analyses using bioinformatics approaches, and classified them into nine subfamilies based on protein sequence similarity. These genes were distributed across 12 chromosomes. Our analysis revealed that LEA promoters contain cis-acting elements associated with anaerobic induction, abscisic acid (ABA) response, and combined low-temperature/light stress, suggesting their role in a multi-tiered environmental signal integration network. Spatio-temporal expression profiling further indicated that root-specific LEA genes maintain cellular integrity via membrane lipid binding, while leaf-predominant members cooperate with the antioxidant system to mitigate photoinhibition damage. Conclusions: This study elucidates the dynamic regulatory mechanisms of the LEA gene family during flooding-drought adaptation in M. laxiflora, providing molecular targets for ecological restoration in the Yangtze River Basin.