Jung, Jinwook , Won, So-Yoon , Suh, Seok Cheol , Kim, HyeRan , Wing, Rod , Jeong, Yeonhwa , Hwang, Ingyu , Kim, Minkyun .
The barley ERF-type transcription factor HvRAF confers enhanced pathogen resistance and salt tolerance in Arabidopsis .
We isolated HvRAF (Hordeum vulgare root abundant factor), a cDNA encoding a novel ERF-type transcription factor from young seedlings of barley. In addition to the most highly conserved AP2/ERF DNA-binding domain, the encoded protein contained an N-terminal MCGGAIL signature sequence, a putative nuclear localization sequence, and a C-terminal acidic transcription activation domain containing a novel mammalian hemopexin domain signature-like sequence. RNA blot analyses revealed that HvRAF transcripts were more abundant in roots than in leaves. HvRAF expression was induced in barley seedlings by various treatment regimes such as SA, ethephon, MeJA, cellulase, and methyl viologen. In a subcellular localization assay, the HvRAF-GFP fusion protein was targeted to the nucleus. The fusion protein of HvRAF with the GAL4 DNA-binding domain strongly activated transcription in yeast. Various deletion mutants of HvRAF indicated that the transactivating activity was localized to the acidic domain of the C-terminal region, and that the hemopexin domain signature-like sequence was important for the activity. Overexpression of the HvRAF gene in Arabidopsis plants induced the activation of various stress-responsive genes. Furthermore, the transgenic Arabidopsis plants showed enhanced resistance to Ralstonia solanacearum strain GMI1000, as well as seed germination and root growth tolerance to high salinity. These results collectively indicate that HvRAF is a transcription factor that plays dual regulatory roles in response to biotic and abiotic stresses in plants.
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1 - Seoul National University, School of Agricultural Biotechnology
2 - RDA, NIAB
3 - University of Arizona, Arizona Genomics Institute
4 - Seoul National University, School of Agricultural Biotechnology, Sillim-dong san 56-1, Seoul, 151-921, Korea
ERF-type transcription factor
Hordeum vulgare root abundant factor
Presentation Type: Plant Biology Abstract
Location: Exhibit Hall (Northeast, Southwest & Southeast)/Hilton
Date: Sunday, July 8th, 2007
Time: 8:00 AM