Abstract:In the present study, 112 bZIP transcription factors were identified from the reference genome of wild diploid peanut, including 55 and 57 family members on AA and BB genome, respectively. All the members were named AradubZIP1-AradubZIP55 and AraipbZIP1-AraipbZIP57. The gene structure, conservative motif, physiochemical properties were predicted through bioinformatics methods. Furthermore, the phylogenetic relationship of bZIP family members was analyzed between peanuts and Arabidopsis, and the subcellular localization was predicted in plant cells. To understand the biological function of these genes under drought stress, the transcriptional profiles of thirty-two members were analyzed by use of the transcriptome sequencing data of peanuts leaves at the late growth stage in a tetraploid peanut L422. The results indicated that the bZIP members in wild diploids were assigned into 10 chromosomes on AA and BB genomes, respectively. Most of them were localized to the nucleus (36 members in AA genome, 39 members in BB genome), and few of them were localized to chloroplasts (14 and 15) and mitochondria (4 and 3). Meanwhile, 25 members with similar gene structure/motif were found on two diploid peanut genome, respectively. The number of exons were variable, for instance that up to 15 exons was found in AraipbZIP5, and one exon was found in 12 bZIP genes. Furthermore, the peanut bZIPs were divided into 14 subgroups (A-M and S). Among these, seven members of tetraploid bZIPs were classified into the I subgroup. Finally, the transcriptional profiles of 32 tetraploid bZIP genes under drought stress treatment were divided into 4 categories, I) the early and late period were higher than the medium period, II) the middle and late period were higher than the early period, III) the early and medium period were higher than the late period, and Ⅳ) the middle period was higher than the early and late period. These results provided a useful reference for understanding the function of bZIP gene family members under the drought stress treatment at the late growth stage in peanut.
