Functional studies of promoter activities from Oncidium Gower Ramsey peroxidase gene in Arabidopsis thaliana.
Date Issued
2008
Date
2008
Author(s)
Hsieh, Yih-Feng
Abstract
Previous studies had shown that expression patterns under abiotic stress of nine class III peroxidase genes isolated from Oncidium substractive cDNA library. Here we cloned a 1.3 kb of Oncidium peroxidase promoter, named Ppox3-19 that was fused with a GUS reporter gene. By using transgenic Arabidopsis, the promoter activity was investigated under various concentrations of different hormones and sucrose. The results revealed that 7-day-old seedlings of transgenic Arabidopsis specifically exhibited higher GUS activities in guard cells in the presence of 5 % sucrose and 100 μM different hormones such as JA, GA3, and ABA. To further characterize the Ppox3-19, a series of deletions of the promoter fused with were established, and transformed into wild-type Arabidopsis. The results revealed that transgenic plants with the full-length of the promoter showed higher GUS activities in guard cells, rather than those with deletion constructs. We concluded that Ppox3-19 contains guard cell-specific cis-elements between -1341 bp and -1291 bp. The regulatory relationship between ABA and guard cells was also analyzed by transforming the Ppox3-19::GUS construct into Arabidopsis aba and abi mutants. Accordingly, it was found that GUS activities were detected in guard cells of abi2 but not in abi1, which indicates that Ppox3-19 be involved in downstream of ABI1 signaling. Thus, the promoter activity of the peroxidase pox3-19 by higher concentration (> 100 μM) of ABA, and a guard cell-specific cis-element may be present in the promoter region from -1343 bp to -1291bp.
Subjects
Oncidium
peroxidase
promoter
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