• Journal of Plant Biotechnology
• /
• v.35 no.3
• /
• pp.169-176
• /
• 2008

Salicylic acid(SA) is a phytohormone that is related to plant defense mechanism. The SA accumulation is triggered by abiotic and biotic stresses. SA acts as a signal molecular compound mediating systemic acquired resistance and hypersensitive response in plant. Although the role of SA has been studied extensively, an understanding of the SA regulatory mechanism is still lacking in plants. In order to comprehend SA regulatory mechanism, we have been transformed with a SID2 promoter:GUS::LUC fusion construct into siz1-2 mutant and wild plant(Col-0). SIZ1 encodes SUMO E3 ligase and negatively regulates SA accumulation in plants. SID2(SALICYLIC ACID INDUCTION DEFICIENT2) is a crucial enzyme of SA biosynthesis. The Arabidopsis SID2 gene encodes isochorismate synthase(ICS) that controls SA level by conversion of chorismate to isochorismate. We compared the regulation of SID2 in wild-type and siz1-2 transgenic plants that express SID2 promoter:GUS::LUC constructs respectively. The expressions of $\beta$-GLUCURONIDASE and LUCIFERASE were higher in siz 1-2 transgenic plant without any stress treatment. SID2 promoter:GUS::LUC/siz1-2 transgenic plant will be used as a starting material for isolation of siz1-2 suppressor mutants and genes involved in SA-mediated stress signaling pathway.

• Journal of Life Science
• /
• v.27 no.2
• /
• pp.194-201
• /
• 2017

Rapeseed (Brassica napus L.) is an oil crop classified as Brassicaceae, and it is widely grown worldwide. To develop a drought-resistant rapeseed, the ${\beta}$-glucosidase 1 (AtBG1) gene was introduced into rapeseed because drought- and salt-resistance phenotypes were observed when the AtBG1 gene was overexpressed in arabidopsis. Newly developed genetically modified crop must be proved to be safe. Safety assessments are based on the historical usage and scientific reports of a crop. In this study, we examined the potential acute oral toxicity of AtBG1 protein expressed in genetically modified (GM) rapeseed and calculated the minimum lethal dose at 6 weeks in both male and female ICR mice. AtBG1 protein was fed at a dose of 2,000 mg/kg body weight in five male and five female mice according to the marginal capacity concentration of OECD, 2,000 mg/15 ml/kg. Mortalities, clinical findings, and body weight changes were monitored for 14 days after dosing, and postmortem necropsy was performed on day 14. This study showed that no deaths occurred in the test group, and AtBG1 protein did not result in variations in common symptoms, body weight, and postmortem findings between the two groups. This showed that the minimum lethal dose of AtBG1 protein expressed in transgenic rapeseed exceed 2,000 mg/kg body weight in both sexes.

• Molecules and Cells
• /
• v.27 no.4
• /
• pp.467-473
• /
• 2009

Our previous study suggested that OsBWMK1, a gene which encodes a member of the rice MAP kinase family, generates transcript variants which show distinct expression patterns in response to environmental stresses. The transcript variants are generated by alternative splicing and by use of alternative promoters. To test whether the two alternative promoters, pOsBWMK1L (promoter for the OsBWMK1L splice variant) and pOsBWMK1S (promoter for the OsBWMK1S splice variant), are biologically functional, we analyzed transgenic plants expressing GUS fusion constructs for each promoter. Both pOsBWMK1L and pOsBWMK1S are biologically active, although the activity of pOsBWMK1S is lower than that of pOsBWMK1L. Histochemical analysis revealed that pOsBWMK1L is constitutively active in most tissues at various developmental stages in rice and Arabidopsis, whereas pOsBWMK1S activity is spatially and temporally restricted. Furthermore, the expression of pOsBWMK1S::GUS was upregulated in response to hydrogen peroxide, a plant defense signaling molecule, in both plant species. These results suggest that the differential expression of OsBWMK1 splice variants is the result of alternative promoter usage and, moreover, that the mechanisms controlling OsBWMK1 gene expression are conserved in both monocot and dicot plants.

• Molecules and Cells
• /
• v.27 no.4
• /
• pp.475-480
• /
• 2009

The transcription of soybean (Glycine max) calmodulin isoform-4 (GmCaM-4) is dramatically induced within 0.5 h of exposure to pathogen or NaCl. Core cis-acting elements that regulate the expression of the GmCaM-4 gene in response to pathogen and salt stress were previously identified, between -1,207 and -1,128 bp, and between -858 and -728 bp, in the GmCaM-4 promoter. Here, we characterized the properties of the DNA-binding complexes that form at the two core cis-acting elements of the GmCaM-4 promoter in pathogen-treated nuclear extracts. We generated GUS reporter constructs harboring various deletions of approximately 1.3-kb GmCaM-4 promoter, and analyzed GUS expression in tobacco plants transformed with these constructs. The GUS expression analysis suggested that the two previously identified core regions are involved in inducing GmCaM-4 expression in the heterologous system. Finally, a transient expression assay of Arabidopsis protoplasts showed that the GmCaM-4 promoter produced greater levels of GUS activity than did the CaMV35S promoter after pathogen or NaCl treatments, suggesting that the GmCaM-4 promoter may be useful in the production of conditional gene expression systems.