# Genome-Wide Identification and Analysis of the MADS-Box Gene Family in Tectona grandis (Teak), a Member of the Lamiaceae Family

## TL;DR

This study identifies and analyzes 87 MADS-box genes in teak, revealing their roles in development and evolution.

## Contribution

The first genome-wide analysis of MADS-box genes in Tectona grandis, revealing unique structural and functional characteristics.

## Key findings

- 87 MADS-box genes were identified in T. grandis, distributed across 18 pseudo-chromosomes.
- Type II MADS-box genes showed greater motif diversity and potential for broader functions.
- MIKC-type genes were particularly active during flower development in teak.

## Abstract

Background: In plants, members of the MADS-box gene family encode transcription factors that regulate a wide range of developmental processes, including cell differentiation, organ identity, floral induction, and responses to environmental stimuli. Moreover, MADS-box genes play central roles in the well-known ABCDE model of floral development. Teak (Tectona grandis), a woody species belonging to the Lamiaceae family, is recognized for its medicinal and agricultural significance. The recent availability of a chromosome-level genome assembly for T. grandis has enabled the genome-wide identification of 87 MADS-box genes, which are distributed across 18 pseudo-chromosomes. Methods: The amino acid sequences of these genes were compared with orthologous proteins from Arabidopsis thaliana, Sesamum indicum, and Amborella trichopoda to infer the phylogenetic relationships. The structures of key floral quartets in the MADS-box proteins were predicted, and the stability of these predicted tetramers were analyzed via molecular dynamics simulations. Results: The phylogenetic analysis classified the genes into 33 Type I and 54 Type II MADS-box members, forming four major clades (MIKCC, MIKC*, Mα, and Mγ), while the Mβ-type clade was absent. A conserved motif analysis revealed that the Type II genes exhibited greater motif diversity than the Type I, suggesting that T. grandis Type II MADS-box genes possess more complex structures and potentially broader functions. The transcriptomic data from different tissues showed that the MIKC-type genes were particularly active during flower development. Although stable over the simulation time, the T. grandis AP3 ortholog had shorter I and K domains and had an odd mode of protein–protein interaction. Conclusion: Overall, the presented genome-wide analysis provides a comprehensive base for understanding the evolutionary diversification of the MADS-box gene family in T. grandis and identifies candidate genes for future structural and functional characterization.