STRUCTURE AND EXPRESSION OF A RICE HSP70 GENE

A genomic hsp70 gene was isolated from a rice IR36 genomic library and 4 794 bp of the gene have been sequenced. The 5' flanking region of t he gene contained a putative TATA box and a typical heat shock element sequence 5'-CTcgGAAccTTCgAG-3'. The amino acid sequence of the rice H SP70 deduced from the coding region shared 84%-92% homologies with tho se of HSP70s from other plant species. An intron 1 939 bp long was ide ntified in the coding region at the codon specifying amino acid 72 (As p), the similar position introns occurring in other intron-containing hsp70 genes. In addition, another intron of 57 bp was found in the 3'- untranslated region in the rice hsp70 gene. Southern blot hybridizatio n showed that rice hsp70 gene family contained at least three members. Analysis of the RNA levels with the gene-specific and non-specific pr obes revealed that the rice hsp70 gene expressed at normal temperature and the expression was enhanced by heat shock treatment.