A 9 bp cis-element in the promoters of class I small heat shock protein genes on chromosome 3 in rice mediates L-azetidine-2-carboxylic acid and heat shock responses.
In rice, the class I small heat shock protein (sHSP-CI) genes were found to be selectively induced by L-azetidine-2-carboxylic acid (AZC) on chromosome 3 but not chromosome 1. Here it is shown that a novel cis-responsive element contributed to the differential regulation. By serial deletion and computational analysis, a 9 bp putative AZC-responsive element (AZRE), GTCCTGGAC, located between nucleotides -186 and -178 relative to the transcription initiation site of Oshsp17.3 was revealed. Deletion of this putative AZRE from the promoter abolished its ability to be induced by AZC. Moreover, electrophoretic mobility shift assay (EMSA) revealed that the AZRE interacted specifically with nuclear proteins from AZC-treated rice seedlings. Two AZRE-protein complexes were detected by EMSA, one of which could be competed out by a canonical heat shock element (HSE). Deletion of the AZRE also affected the HS response. Furthermore, transient co-expression of the heat shock factor OsHsfA4b with the AZRE in the promoter of Oshsp17.3 was effective. The requirement for the putative AZRE for AZC and HS responses in transgenic Arabidopsis was also shown. Thus, AZRE represents an alternative form of heat HSE, and its interaction with canonical HSEs through heat shock factors may be required to respond to HS and AZC.
Guan
Jiahn-Chou
JC
Institute of Plant Biology, National Taiwan University, Taipei, Taiwan.
Yeh
Ching-Hui
CH
Lin
Ya-Ping
YP
Ke
Yi-Ting
YT
Chen
Ming-Tse
MT
You
Jia-Wen
JW
Liu
Yi-Hsin
YH
Lu
Chung-An
CA
Wu
Shaw-Jye
SJ
Lin
Chu-Yung
CY
D017360:Arabidopsis / Q000187:drug effects / Q000235:genetics; D001383:Azetidinecarboxylic Acid / Q000494:pharmacology*; D020029:Base Pairing / Q000235:genetics*; D001483:Base Sequence; D032461:Chromosomes, Plant / Q000235:genetics*; D024202:Electrophoretic Mobility Shift Assay; D018506:Gene Expression Regulation, Plant / Q000187:drug effects; D017343:Genes, Plant / Q000235:genetics; D050888:Heat-Shock Proteins, Small / Q000235:genetics* / Q000378:metabolism; D018869:Heat-Shock Response / Q000187:drug effects* / Q000235:genetics; D008969:Molecular Sequence Data; D009687:Nuclear Proteins / Q000378:metabolism; D012275:Oryza / Q000187:drug effects / Q000235:genetics*; D010940:Plant Proteins / Q000235:genetics / Q000378:metabolism; D030821:Plants, Genetically Modified; D011401:Promoter Regions, Genetic; D011485:Protein Binding / Q000187:drug effects; D014176:Protein Biosynthesis / Q000187:drug effects; D011500:Protein Synthesis Inhibitors / Q000494:pharmacology; D020218:Response Elements / Q000235:genetics; D016415:Sequence Alignment; D017384:Sequence Deletion; D013312:Stress, Physiological / Q000187:drug effects / Q000235:genetics
D050888:Heat-Shock Proteins, Small; D009687:Nuclear Proteins; D010940:Plant Proteins; D011500:Protein Synthesis Inhibitors; D001383:Azetidinecarboxylic Acid