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Molecular characterization of the sweet potato peroxidase SWPA4 promoter which responds to abiotic stresses and pathogen infection
Author(s) -
Ryu SunHwa,
Kim YunHee,
Kim Cha Young,
Park SooYoung,
Kwon SukYoon,
Lee HaengSoon,
Kwak SangSoo
Publication year - 2009
Publication title -
physiologia plantarum
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.351
H-Index - 146
eISSN - 1399-3054
pISSN - 0031-9317
DOI - 10.1111/j.1399-3054.2008.01197.x
Subject(s) - cauliflower mosaic virus , promoter , biology , microbiology and biotechnology , reporter gene , gene , activator (genetics) , abiotic stress , transgene , gus reporter system , transcription factor , electrophoretic mobility shift assay , transcription (linguistics) , pathogenesis related protein , peroxidase , gene expression , genetically modified crops , genetics , enzyme , biochemistry , linguistics , philosophy
Previously, the swpa4 peroxidase gene has been shown to be inducible by a variety of abiotic stresses and pathogenic infections in sweet potato ( Ipomoea batatas ). To elucidate its regulatory mechanism at the transcriptional level under various stress conditions, we isolated and characterized the promoter region (2374 bp) of swpa4 (referred to as SWPA4 ). We performed a transient expression assay in tobacco protoplasts with deletions from the 5′‐end of SWPA4 promoter fused to the β‐glucuronidase (GUS) reporter gene. The −1408 and −374 bp deletions relative to the transcription start site (+1) showed 8 and 4.5 times higher GUS expression than the cauliflower mosaic virus 35S promoter, respectively. In addition, transgenic tobacco plants expressing GUS under the control of −2374, −1408 or −374 bp region of SWPA4 promoter were generated and studied in various tissues under abiotic stresses and pathogen infection. Gel mobility shift assays revealed that nuclear proteins from sweet potato cultured cells specifically interacted with 60‐bp fragment (−178/−118) in −374 bp promoter region. In silico analysis indicated that four kinds of cis ‐acting regulatory sequences, reactive oxygen species‐related element activator protein 1 (AP1), CCAAT/enhancer‐binding protein alpha element, ethylene‐responsive element (ERE) and heat‐shock element, are present in the −60 bp region (−178/−118), suggesting that the −60 bp region might be associated with stress inducibility of the SWPA4 promoter.