Genome-wide expression analysis of HSP70 family genes in rice and identification of a cytosolic HSP70 gene highly induced under heat stress

• DOI: 10.1007/s10142-013-0331-6
• Publication Date: 2013-07-13T10:28:22Z
• Authors: Ki-Hong Jung; Hyun-Jung Gho; Minh Xuan Nguyen; Sung-Ryul Kim; Gynheung An
• Keywords: 0301 basic medicine; 2. Zero hunger; Hot Temperature; Sequence Homology, Amino Acid; Gene Expression Profiling; Arabidopsis; Oryza; 03 medical and health sciences; Cytosol; Gene Expression Regulation, Plant; Mutation; HSP70 Heat-Shock Proteins; Genome, Plant; Heat-Shock Response; Phylogeny; Oligonucleotide Array Sequence Analysis

The heat shock protein 70 (HSP70) gene family plays a key role in protecting plant cells or tissues from thermal or oxidative stress. Although many studies have elucidated the molecular functions of individual family members, genome-wide analysis of this family is still limited, especially for crop species. Our objective was to integrate various meta-profiling data into the context of a phylogenetic tree, which would enable us to perform fine evaluation of functional dominancy or redundancy within this family. Our data indicated that a loss-of-function mutant of a rice cytosolic HSP70 gene (OsctHSP70-1) did not show a clear defective phenotype in response to high temperature because of the existence of another gene family member that was closely clustered with OsctHSP70-1 and had similar expression patterns. Moreover, the second gene showed much stronger anatomical expression. We indirectly analyzed the function of OsctHSP70-1 by studying GUS activity under the control of the endogenous promoter. We also designed a probable interaction network mediated by OsctHSP70-1 and used co-expression analysis among its components to refine the network, suggesting more probable model to explain the function of OsctHSP70-1.