研究期間：10108~10207;Our previous studies have shown that the expression profiles of rice class I small heat shock protein (sHSP-CIs) genes were diversified in response to heat and azetidine (AZC) stresses. We have found that an AZRE (Azetidine responsive element; GTCCTGGACG), localized on the promoter regions of Oshsp17.3 and Oshsp18.0 genes, was associated with OshsfA4b and heat shock elements (HSEs) to regulate heat shock response and AZC-induced cytosolic protein response. However, OshsfA4b and AZRE did not involve in the induction of Oshsp16.9A gene under heat stress. In this three-year project, our major goal is to further study the differential regulatory mechanism for heat shock factors (HSFs) on the induction of sHSP-CIs genes. Firstly, we are trying to analyze the effects of AZRE and HSEs on the HSF-regulated expression of sHSP-CI genes. Secondly, we plan to search the promoter regions of non-sHSP-CI genes, which contained AZRE, and characterize physiological functions and expression patterns of these genes under heat and AZC treatments. Based on these results, we are able to understand the conservation and physiological role of AZRE in rice genome. Thirdly, the results indicated that copper and cadmium could activate some sHSP-CI gene expression under normal temperatures (for example OsHSP17.3 and OsHSP18.0). Thus we plan to study the roles of HSFs, AZRE, and HSEs in differential activation of sHSP-CI genes under copper and cadmium treatment. Besides, we also try to screen the novel transcription factor(s) or element(s) in response to copper and cadmium stresses. Furthermore we plan to test whether these factors can interact with HSFs to regulate plant growth under various stresses.
