Genome Wide Identification Of BZIP Genes In Foxtail Millet And Green Millet And Gene Function Analysis Of SibZIP8

Drought is one of the major abiotic stress factors influencing crop production.Foxtail millet(Setaria italica)and green millet(Setaria viridis)have many advantages such as drought resistance and barren tolerance,which is excellent germplasms to investigate drought-resistant genes.b ZIP transcription factors are known to play key roles in plant defense against various abiotic stresses.b ZIP genes have been identified in many plants,however,comparative analysis of foxtail millet and green millet b ZIP genes has not been performed.In this study,a genome wide identification of foxtail millet and green millet b ZIP genes was performed using bioinformatics and molecular biology methods.The characteristics of the Sib ZIP and Svb ZIP proteins,chromosome location,phenotypic relationship,gene structure,motif analysis and differential expression were analysed in detail.Main results are as following:1)The current study identified 90 Sib ZIP and 89 Svb ZIP genes.The genes were named Sib ZIP1 to Sib ZIP90 and Svb ZIP1 to Svb ZIP89,respectively,according to their order on the chromosomes.Phylogenetic analysis categorized 342 bzip proteins from four plants foxtail millet,green millet,rice and Arabidopsis,into 10 groups including A?B?C?D?E?F?G?H?I and S.The groups A?D?G?I and S contained more than 9 genes.A comprehensive expression analysis of Sib ZIPs genes among four different tissues was performed using publicly available RNA sequencing data.The heat map showed that most Sib ZIPs were highly expressed in at least one of the four tested tissues.Additionally,based on a 10 green millet transcriptome data from GEO database,a comprehensive expression analysis of Svb ZIPs genes among ten different tissues was performed.2)In order to further identify the function of SibZIP8 gene,subcellular localization of SibZIP8 and over-expression of SibZIP8 were applied.The resistance phenotype of transgenic plants was analyzed.Our results showed that the germination of transgenic Arabidopsis was higher than wild type plants under Na Cl conditions.Moreover,significant difference was found between transgenic and wild type plants when withdraw water and re-watering,indicating that over-expression of SibZIP8 increased the drought tolerance in transgenic plants.Our work could provide new knowledge for analysing the molecular mechanism ofmillet drought resistance and new genes for drought stress resistance breeding in plants.