A tuber mustard AP2/ERF transcription factor gene, BjABR1 , functioning in abscisic acid and abiotic stress responses, and evolutionary trajectory of the ABR1 homologous genes in Brassica species

• Published in: PeerJ (San Francisco, CA) Vol. 6; p. e6071
• Main Authors: Xiang, Liuxin, Liu, Chao, Luo, Jingzhi, He, Lin, Deng, Yushan, Yuan, Jie, Wu, Chaofeng, Cai, Yingfan
• Format: Journal Article
• Language: English
• Published: United States PeerJ. Ltd 11-12-2018; PeerJ, Inc; PeerJ Inc
• Subjects: Abiotic stress; Abiotic stress and abscisic acid responses; ABR1 homologous genes; Abscisic acid; Amino acid sequence; Amino acids; Analysis; Arabidopsis; Arabidopsis thaliana; Bioinformatics; Biology; BjABR1; Brassica; Brassica rapa; Brassica species; Brassicaceae; Crops; Deoxyribonucleic acid; Diploids; DNA; DNA binding proteins; Evolution (Biology); Evolutionary genetics; Evolutionary trajectory; Explosions; Gene expression; Genes; Genetic aspects; Genetic research; Genomes; Genomics; Laboratories; Molecular Biology; Phylogeny; Physiological aspects; Plant development; Plant hormones; Plant Science; Species; Transcription factors; Tuber mustard; Wildlife conservation; China; Abiotic stress and abscisic acid responses; Evolutionary trajectory; Tuber mustard; BjABR1; Brassica species; ABR1 homologous genes
• ISSN: 2167-8359; 2167-8359
• DOI: 10.7717/peerj.6071

The AP2/ERF superfamily of transcription factors is one of the largest transcription factor families in plants and plays an important role in plant development processes and stress responses. In this study,
, an AP2/ERF superfamily gene, from tuber mustard (
var.
Tsen et Lee), sharing high amino acid sequence similarity with the
(
AP2-like abscisic acid repressor 1) gene, were performed functional research, and the
homologous genes in
species were identified and performed phylogenetic analysis. The promoter sequence of
contained many phytohormone- and stress-related cis-elements; ABA (abscisic acid) and abiotic stresses can induce
expression in tuber mustard; overexpression of
in
can alleviate plant sensitivity to ABA and salt and osmotic stresses, and the alleviation may be due to changes in stress/ABA-induced gene expression. These results indicated that
functions in ABA and abiotic stress responses. By BLAST searches against the genome database of five
species (three diploids,
,
, and
, and two allotetraploid,
and
) using the protein sequence of
, 3, 3, 3, 6, and 5
homologous genes in
,
,
,
, and
were identified, respectively, and they shared high sequence similarity. By sequence analysis, annotation mistakes of the protein-coding regions of two
homologous genes,
and
, were found and corrected. Then, the evolution analysis of these
homologous genes showed that the ancestor of the three diploid species had three
homologous genes and each diploid inherited all the three genes from their ancestor; then, allotetraploid
inherited all the six genes from
and
with no gene lost, while allotetraploid
inherited all the three genes from
and two genes from
with one gene lost, indicating that
homologous genes possessed greater hereditary conservation in
species. The
homologous genes between
and
shared much higher sequence similarity compared to that of
in diploid species, indicating that
homologous genes in
had experienced more rapid evolution, and
and
may share closer relationship compared to
. Moreover, the spatial and temporal expression analysis of six
homologous genes of tuber mustard showed that they possessed different expression models. These results imply that
homologous genes are important to
plants, and they may possess similar function in ABA and abiotic stress responses but play a role in different tissues and growing stages of plant. This study will provide the foundation to the functional research of
homologous genes in the
species and help to reveal and understand the evolution mechanisms of
species.