Expression Pattern and Genome-Wide Analysis of HSP90 Gene Family in Aeluropus littoralis under Salinity Stress

HSP90 protein is an ATP-dependent molecular chaperone that is evolutionarily conserved in bacteria to higher eukaryotes. In plants, HSP90s are required for control of normal plant growth and development, as well as immune responses to environmental stimuli. Although there are several studies explaining the physiological role of HSP90s in plants, our understanding of their stress response molecular mechanisms, their roles as molecular chaperones, and their molecular interactions with other clients and co-chaperones is still unclear. Therefore the present study aimed to performed a comprehensive analysis of the HSP90 gene family in halophyte plant Aeluropus littoralis. Subcellular localization analysis showed that four identified AlHSP90 gene were localized in different subcellular compartments. Based on different bioinformatics tools, 45 HSP90 homologus genes were identifed from Arabidopsis, rice, maize, soybeen and Brachypodium distachyon species. 49 genes of HSP90 were phylogenetically clustered into three major groups. Gene structure and motif composition revealed that these genes were relatively conservative in each group, suggesting that members of the same group may also have conserved functions. Based on RNA-seq data, AlHSP90.4 gene localized in cytoplasm with expression levels of 1.3 was expressed more in root tissue under salinity stress and recovery. The least expression level was observed in AlHSP90.3 gene localized in ER in root tissue under salinity stress and recovery. The findings of this study reveal the functional characteristics of the AlHSP90 genes and provide basic information for future research on the their biological functions.