Genome-Wide Analysis of the MADS-Box Gene Family and Expression Pattern Under Abiotic Stresses in Lilium davidii var....

The MADS-box gene family encodes a critical class of transcription factors that regulate diverse developmental processes in plants. However, its role in abiotic stress responses remains poorly characterized in Lilium davidii var. unicolor (Lanzhou lily). In this study, we identified 62 LdMADS genes in the Lanzhou lily genome, classifying them into 17 Type I and 45 Type II members. Notably, the SOC1 subfamily exhibited a pronounced expansion. These LdMADS members were distributed across all twelve chromosomes and displayed considerable structural variation, with some genes harboring exceptionally long introns. Tissue-specific expression profiling revealed that M-type and MIKC* genes were predominantly and specifically expressed in ovaries and anthers, whereas MIKC^C members exhibited complex and diverse expression patterns across multiple tissues. The selection of candidate LdMADS genes for abiotic stress response was based on their transcript abundance in leaf and root tissues, together with the enrichment of their cis-acting elements. The expression of these LdMADS genes under drought, heat, and cold stresses was further examined by qRT-PCR. Among them, LdMADS4 and LdMADS14 from the SEP subfamily, as well as LdMADS25 and LdMADS26 from the SOC1 subfamily, responded to multiple stress conditions. This study provides functional clues for the roles of MADS-box genes in the development and stress responses of Lanzhou Lily.