AUTHOR=Zhao Jiao , Guo Rongrong , Guo Chunlei , Hou Hongmin , Wang Xiping , Gao Hua 

TITLE=Evolutionary and Expression Analyses of the Apple Basic Leucine Zipper Transcription Factor Family

JOURNAL=Frontiers in Plant Science

VOLUME=Volume 7 - 2016

YEAR=2016

URL=https://www.frontiersin.org/journals/plant-science/articles/10.3389/fpls.2016.00376

DOI=10.3389/fpls.2016.00376

ISSN=1664-462X

ABSTRACT=<p>Transcription factors (TFs) play essential roles in the regulatory networks controlling many developmental processes in plants. Members of the basic leucine (Leu) zipper (bZIP) TF family, which is unique to eukaryotes, are involved in regulating diverse processes, including flower and vascular development, seed maturation, stress signaling, and defense responses to pathogens. The bZIP proteins have a characteristic bZIP domain composed of a DNA-binding basic region and a Leu zipper dimerization region. In this study, we identified 112 apple (<italic>Malus domestica</italic> Borkh) bZIP TF-encoding genes, termed <italic>MdbZIP</italic> genes. Synteny analysis indicated that segmental and tandem duplication events, as well as whole genome duplication, have contributed to the expansion of the apple bZIP family. The family could be divided into 11 groups based on structural features of the encoded proteins, as well as on the phylogenetic relationship of the apple bZIP proteins to those of the model plant <italic>Arabidopsis thaliana</italic> (<italic>AtbZIP</italic> genes). Synteny analysis revealed that several paired <italic>MdbZIP</italic> genes and <italic>AtbZIP</italic> gene homologs were located in syntenic genomic regions. Furthermore, expression analyses of group A <italic>MdbZIP</italic> genes showed distinct expression levels in 10 different organs. Moreover, changes in these expression profiles in response to abiotic stress conditions and various hormone treatments identified <italic>MdbZIP</italic> genes that were responsive to high salinity and drought, as well as to different phytohormones.</p>