Characterization of the genomic structures and selective expression profiles of nine class I small heat shock protein genes clustered on two chromosomes in rice (Oryza sativa L.).
The cytosolic class I small heat shock proteins (sHSP-CI) represent the most abundant sHSP in plants. Here, we report the characterization and the expression profile of nine members of the sHSP-CI gene family in rice (Oryza sativa Tainung No.67), of which Oshsp16.9A, Oshsp16.9B, Oshsp16.9C, Oshsp16.9D and Oshsp17.9B are clustered on chromosome 1, and Oshsp17.3, Oshsp17.7, Oshsp17.9A and Oshsp18.0 are clustered on chromosome 3. Oshsp17.3 and Oshsp18.0 are linked by a 356-bp putative bi-directional promoter. Individual gene products were identified from the protein subunits of a heat shock complex (HSC) and from in vitro transcription/ translation products by two-dimensional gel electrophoreses (2-DE). All sHSP-CI genes except Oshsp17.9B were induced strongly after a 2-h heat shock treatment. The genes on chromosome 3 were induced rapidly at 32 and 41 degrees C, whereas those on chromosome 1 were induced slowly by similar conditions. Seven of these genes, except Oshsp16.9D and Oshsp17.9B, were induced by arsenite (As), but only genes on chromosome 3 were strongly induced by azetidine-2-carboxylic acid (Aze, a proline analog) and cadmium (Cd). A similar expression profile of all sHSP-CI genes at a lower level was evoked by ethanol, H2O2 and CuCl2 treatments. Transient expression assays of the promoter activity by linking to GUS reporter gene also supported the in vivo selective expression of the sHSP-CI genes by Aze treatment indicating the differential induction of rice sHSP-CI genes is most likely regulated at the transcriptional level. Only Oshsp16.9A abundantly accumulated in mature dry seed also suggested additionally prominent roles played by this HSP in development.
Guan
Jiahn-Chou
JC
Institute of Plant Biology, National Taiwan University, Taipei 106, Taiwan, ROC.
Jinn
Tsung-Luo
TL
Yeh
Ching-Hui
CH
Feng
Shi-Pin
SP
Chen
Yih-Ming
YM
Lin
Chu-Yung
CY
D001383:Azetidinecarboxylic Acid / Q000494:pharmacology; D001483:Base Sequence; D015153:Blotting, Western; D002874:Chromosome Mapping; D032461:Chromosomes, Plant / Q000235:genetics*; D020869:Gene Expression Profiling; D018507:Gene Expression Regulation, Developmental; D018506:Gene Expression Regulation, Plant / Q000187:drug effects; D023061:Gene Order; D005966:Glucuronidase / Q000235:genetics / Q000378:metabolism; D006360:Heat-Shock Proteins / Q000235:genetics* / Q000378:metabolism; D006861:Hydrogen Peroxide / Q000494:pharmacology; D008969:Molecular Sequence Data; D005810:Multigene Family / Q000235:genetics*; D012275:Oryza / Q000187:drug effects / Q000235:genetics* / Q000378:metabolism; D010802:Phylogeny; D010940:Plant Proteins / Q000235:genetics / Q000378:metabolism; D011401:Promoter Regions, Genetic / Q000235:genetics; D011993:Recombinant Fusion Proteins / Q000235:genetics / Q000378:metabolism; D020133:Reverse Transcriptase Polymerase Chain Reaction; D012639:Seeds / Q000235:genetics / Q000254:growth & development; D013696:Temperature
D006360:Heat-Shock Proteins; D010940:Plant Proteins; D011993:Recombinant Fusion Proteins; D001383:Azetidinecarboxylic Acid; D006861:Hydrogen Peroxide; D005966:Glucuronidase