Data from: Genome-wide analysis of the basic leucine zipper (bZIP) transcription factor gene family in six legume genomes

Background: Plant bZIP proteins characteristically harbor a highly
conserved bZIP domain with two structural features: a DNA-binding basic
region and a leucine (Leu) zipper dimerization region. They have been
shown to be diverse transcriptional regulators, playing crucial roles in
plant development, physiological processes, and biotic/abiotic stress
responses. Despite the availability of six completely sequenced legume
genomes, a comprehensive investigation of bZIP family members in legumes
has yet to be presented. Results: In this study, we identified 428 bZIP
genes encoding 585 distinct proteins in six legumes, Glycine max, Medicago
truncatula,Phaseolus vulgaris, Cicer arietinum, Cajanus cajan, and Lotus
japonicus. The legume bZIP genes were categorized into 11 groups according
to their phylogenetic relationships with genes from Arabidopsis. Four
kinds of intron patterns (a–d) within the basic and hinge regions were
defined and additional conserved motifs were identified, both presenting
high group specificity and supporting the group classification. We
predicted the DNA-binding patterns and the dimerization properties, based
on the characteristic features in the basic and hinge regions and the Leu
zipper, respectively, which indicated that some highly conserved amino
acid residues existed across each major group. The chromosome distribution
and analysis for WGD-derived duplicated blocks revealed that the legume
bZIP genes have expanded mainly by segmental duplication rather than
tandem duplication. Expression data further revealed that the legume bZIP
genes were expressed constitutively or in an organ-specific,
development-dependent manner playing roles in multiple seed developmental
stages and tissues. We also detected several key legume bZIP genes
involved in drought- and salt-responses by comparing fold changes of
expression values in drought-stressed or salt-stressed roots and leaves.
Conclusions: In summary, this genome-wide identification, characterization
and expression analysis of legume bZIP genes provides valuable information
for understanding the molecular functions and evolution of the legume bZIP
transcription factor family, and highlights potential legume bZIP genes
involved in regulating tissue development and abiotic stress responses.