ANNOUNCEMENTS
The Brassicaceae family, belongs to mustard family, is known for its unique floral structure, particularly the presence of tetradynamous stamens—a configuration of two short and four long stamens—which enhances pollination efficiency. In this study, the role of the Dormancy-Associated Protein Homolog 1 (DRM-1) gene is investigated in filament development in Brassica juncea L. cv. Varuna. By integrating in silico analysis, RT-PCR, and cloning techniques, we aimed to understand the gene's function and regulatory behaviour. Expression analysis using RNA-seq data and RT-PCR from 14 candidate genes revealed that DRM-1 is upregulated in flowers with short filaments, pointing to its involvement in dormancy regulation and stress-responsive pathways during floral development. Cloning and characterization of the Bj.DRMB06 variant identified a 132-amino-acid protein localized in the cytoplasm. Physiochemical properties, including a high isoelectric point (pI = 10.32) and negative GRAVY score (-1.01), indicated a basic, hydrophilic protein that is likely metabolically active. Despite its instability index (42.57) and low aliphatic index, which suggest limited thermostability, its structure supports important cellular functions.
Motif and domain analysis (MEME and CDD) highlighted a highly conserved auxin-repressed domain, with divergence seen in some homologs—possibly due to neofunctionalization. Phylogenetic trees based on genomic, CDS, and protein sequences (constructed via MEGA) showed both conservation and divergence, influenced by gene duplication and exon-intron variation. Finally, protein-protein interaction analysis using STRING revealed that DRM-1 is part of a broader network involving proteins linked to DNA methylation (DRM-3), RNA splicing (RS31A, U2AF65A), cell division (KINB1, KING1), and nitrogen metabolism (ASN1).
Together, these findings highlight DRM-1’s critical role in stamen development and its potential function in broader stress response and reproductive regulation.
Keywords: Brassicaceae, DRM-1, filament development, tetradynamous condition, RT-PCR, in silico analysis, gene expression, phylogenetic tree, auxin-repressed domain, floral morphogenesis, stamen evolution.
