Abstract:
Auxin is a key phytohormone that orchestrates diverse processes in plant growth and development. Twisted dwarf 1 (TWD1) is known to facilitate the folding and functional maturation of auxin transporter proteins within the secretory pathway. In this study, a homolog of
Arabidopsis thaliana (L.) Heynh
AtTWD1 was identified and cloned from
Neolamarckia cadamba (Roxb.) Bosser using integrated bioinformatics and molecular approaches, designated
NcTWD1. Results indicated that the
NcTWD1 sequence was 1 098 bp in length, encoding a 365-amino acid protein. Structural modeling indicated that NcTWD1 and AtTWD1 share highly similar tertiary conformations, each containing an FKBP domain, a TRP domain, and a C-terminal membrane-anchoring domain. RT-qPCR analysis demonstrated that
NcTWD1 is expressed across multiple tissues, including roots, stems, shoot tips, young leaves, mature leaves, petioles, and seedlings. Subcellular localization revealed predominant accumulation of NcTWD1 within the endoplasmic reticulum. Overexpression of
NcTWD1 in the
A. thaliana twd1-4 mutant rescued its characteristic dwarf and twisted phenotypes. Co-immunoprecipitation assays further confirmed a physical interaction between NcTWD1 and the auxin transporter NcABCB1 in
N. cadamba, indicating that NcTWD1 likely performs a conserved regulatory role analogous to AtTWD1 in
A. thaliana.