Identification of Ethanol-inducible Genes and Isolation of the Myb-related Protein-like Promoter in Oryza sativa L.

Abstract

The ethanol-inducible system derived from Aspergillus nidulans has been used for gene expression analysis in plants. However, the response of non-transformed plants to ethanol suggests that this system may be present in plants. Therefore, it is possible to use an ethanol-inducible promoter derived from plants for gene regulation. In this study, effects of ethanol on rice growth were examined and an ethanol-inducible gene from rice was identified. The ethanol-inducible transcript-derived fragments (TDFs) were identified using cDNA-AFLP. These TDFs corresponded to genes involving different pathways including stress response. Using semi-quantitative RT-PCR, five TDFs, which were homologous to Os07g0240300, Os02g0175700, Os05g0392100, Os03g0569000, Os07g0627300, and adh2, were up-regulated. Among them, Os07g0627300 is highly conserved and expressed in several tissues; therefore, the promoter of Os07g0627300 was isolated and analyzed for motifs and promoter activity. The results indicated that it was a TATA-less promoter containing a number of motifs involved in stress responses. Transient expression results revealed that this promoter had ethanol-inducible promoter activity. These findings suggested that the Os07g0627300 promoter could be used as a useful tool for regulating gene expression in plants and could be used to generate transgenic crops with desirable traits.