Genome-Wide Identification and Expression Analysis of the Mediator Complex Subunit Gene Family in Cassava

The Mediator complex (MED) functions as a co-activator in plants, transmitting transcriptional signals to regulate gene expression, including responses to environmental stresses. While the MED gene family has been identified in several species, it has not yet been reported in cassava. In this study, we identified 32 members of the MeMED gene family in cassava (Manihot esculenta Crantz) distributed across 13 chromosomes. These genes were categorized into distinct Mediator subunits based on their similarity to Arabidopsis modules. Promoter analysis revealed the presence of various cis-regulatory elements, which likely play key roles in regulating plant growth, development, and stress responses. RNA-seq data showed tissue-specific expression patterns for the MeMED genes, with significant expression observed in leaves, roots, petioles, stems, friable embryogenic callus, and shoot apical meristems. Further RT-qPCR analysis under various abiotic stress conditions-including drought, exogenous hydrogen peroxide, cold, heat, and salt-demonstrated that 10 selected MeMED genes exhibited significant differential expression, indicating their potential functional involvement in stress adaptation. These findings offer insights into the biological roles of the MeMED gene family in cassava, with implications for improving stress tolerance in future breeding programs.