Evolutionary divergence of motifs in B-class MADS-box proteins of seed plants

Journal of Biological Research-Thessaloniki

Yong Jia¹  Wei-Lung Wang²  Gangxu Shen³ 

[1] College of Science, Health, Engineering and Education, Murdoch University, 6150, Murdoch, WA, Australia;Department of Biology, National Changhua University of Education, 500, Changhua, Taiwan;School of Chinese Medicine for Post-Baccalaureate, I-Shou University, 84001, Kaohsiung, Taiwan;Department of Biology, National Changhua University of Education, 500, Changhua, Taiwan;

关键词: B gene;    MADS-box gene;    MADS domain;    MEME;    Amborella trichopoda;   

DOI  :  10.1186/s40709-021-00144-7

来源: Springer

【 摘 要 】

BackgroundMADS-box transcription factors function as homo- or heterodimers and regulate many aspects of plant development; moreover, MADS-box genes have undergone extensive duplication and divergence. For example, the morphological diversity of floral organs is closely related to the functional divergence of the MADS-box gene family. B-class genes (such as Arabidopsis thaliana APETALA3 [AP3] and PISTILLATA [PI]) belong to a subgroup of MADS-box genes. Here, we collected 97 MADS-box B protein sequences from 21 seed plant species and examined their motifs to better understand the functional evolution of B proteins.ResultsWe used the MEME tool to identify conserved sequence motifs in these B proteins; unique motif arrangements and sequences were identified in these B proteins. The keratin-like domains of Malus domestica and Populus trichocarpa B proteins differed from those in other angiosperms, suggesting that a novel regulatory network might have evolved in these species. The MADS domains of Nelumbo nucifera, Glycine max, and Amborella trichopoda B-proteins contained motif 9; in contrast, those of other plants contained motif 1. Protein modelling analyses revealed that MADS domains with motif 9 may lack amino acid sites required for DNA-binding. These results suggested that the three species might share an alternative mechanism controlling floral development.ConclusionsAmborella trichopoda has B proteins with either motif 1 or motif 9 MADS domains, suggesting that these two types of MADS domains evolved from the ancestral domain into two groups, those with motif 9 (N. nucifera and G. max), and those with motif 1. Moreover, our results suggest that the homodimer/heterodimer intermediate transition structure first appeared in A. trichopoda. Therefore, our systematic analysis of the motifs in B proteins sheds light on the evolution of these important transcription factors.

【 授权许可】

CC BY