Molecular characterization of the sweet potato peroxidase SWPA4 promoter which responds to abiotic stresses and pathogen infection.
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 beta-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.
Ryu
Sun-Hwa
SH
Environmental Biotechnology Research Center, Korea Research Institute of Bioscience and Biotechnology (KRIBB), Daejeon, Korea.
Kim
Yun-Hee
YH
Kim
Cha Young
CY
Park
Soo-Young
SY
Kwon
Suk-Yoon
SY
Lee
Haeng-Soon
HS
Kwak
Sang-Soo
SS
D002478:Cells, Cultured; D016386:Chromosome Walking; D018506:Gene Expression Regulation, Plant; D006861:Hydrogen Peroxide / Q000494:pharmacology; D027723:Ipomoea batatas / Q000187:drug effects / Q000235:genetics* / Q000378:metabolism / Q000382:microbiology; D010544:Peroxidases / Q000235:genetics*; D010940:Plant Proteins / Q000235:genetics*; D030821:Plants, Genetically Modified / Q000187:drug effects / Q000235:genetics / Q000378:metabolism / Q000382:microbiology; D011401:Promoter Regions, Genetic; D044224:Pseudomonas syringae / Q000502:physiology; D018749:RNA, Plant / Q000235:genetics; D013312:Stress, Physiological; D014026:Nicotiana / Q000235:genetics
D010940:Plant Proteins; D018749:RNA, Plant; D006861:Hydrogen Peroxide; D010544:Peroxidases