Genome-wide Identification of the Aspergillus oryzae GATA Transcription Factor Gene Family and expression Analysis under Temperature or Salt Stresses

Abstract

Background GATA transcription factors (TFs) are transcriptional regulatory proteins that contain a characteristic type-IV zinc finger and recognize the conserved GATA motif in the promoter region. Previous studies demonstrate that GATA TFs are involved in the regulation of diverse growth processes and various environmental stimuli stresses. Although the analysis of GATA TFs involved in abiotic stress have been performed in model plants and some fungi, information regarding GATA TFs in A. oryzae is extremely poor. Results Therefore, we identified seven GATA TFs from A. oryzae 3.042 genome, and named AoAreA, AoAreB, AoLreA, AoLreB, AoNsdD, AoSreA in correspondence to fungal orthologs, including a novel AoSnf5 with 20-residue between the Cys-X2-Cys motifs which was found in Aspergillus for the first time. Six known A. oryzae GATA TFs were classified into six subgroups, while the novel AoSnf5 also clustered into NSDD subgroups together with AoNsdD in the NJ_tree of all Aspergillus GATA TFs. Conserved motifs demonstrated that GATA TFs with similar motif compositions clustered into one subgroup, which suggests they might have similar genetic functions and further confirms the accuracy of the phylogenetic relationship of Aspergillus GATA TFs. The expression patterns of seven A. oryzae GATA TFs exhibited diversity under temperature and salt stresses. The expression analyses of AoLreA and AoLreB demonstrates AoLreA mainly played role in salt stress and AoLreB did under temperature stress. AoSreA was shown to positively regulate the expression of AoCreA and might act as a negative regulator in temperature and high salt stress response. In addition, the AoNsdD, AoSnf5, AoAreB, and AoAreA strongly responsed to salt stresses, while AoAreB and AoAreA showed opposite expression trends at high temperature. Overall, the expression patterns of these A. oryzae GATA TFs under distinct environmental conditions provided useful information for the further analysis of GATA TFs in regulation of various abiotic stress in A. oryzae. Conclusion In conclusion, the comprehensive analysis data of A. oryzae GATA TFs will provide insights into the critical role of A. oryzae GATA TFs in resistance to temperature and salt stresses in A. oryzae.