• Proceedings of the Korean Society of Plant Biotechnology Conference
• /
• 2004.10a
• /
• pp.162-162
• /
• 2004

• Molecules and Cells
• /
• v.41 no.4
• /
• pp.342-350
• /
• 2018

Flowering time is determined by florigens. These genes include, Heading date 3a (Hd3a) and Rice FT 1 (RFT1) in rice, which are specifically expressed in the vascular tissues of leaves at the floral transition stage. To study the cis-regulatory elements present in the promoter region of Hd3a, we generated transgenic plants carrying the 1.75-kb promoter fragment of Hd3a that was fused to the ${\beta}$-glucuronidase (GUS) reporter gene. Plants expressing this construct conferred a vascular cell-specific expression pattern for the reporter gene. However, GUS was expressed in leaves at all developmental stages, including the early seedling stage when Hd3a was not detected. Furthermore, the reporter was expressed in roots at all stages. This suggests that the 1.75-kb region lackings cis-elements that regulate leaf-specific expression at the appropriate developmental stages. Deletion analyses of the promoter region indicated that regulatory elements determining vascular cell-specific expression are present in the 200-bp region between -245 bp and -45 bp from the transcription initiation site. By transforming the Hd3a-GUS construct to rice cultivar 'Taichung 65' which is defective in Ehd1, we observed that Ehd1 is the major regulatory element that controls Hd3a promoter activity.

• Journal of Plant Biology
• /
• v.39 no.2
• /
• pp.93-98
• /
• 1996

In order to enhance the system of potato transformation and further regeneration, potato was transformed using the Agrobacterium tumefaciens harboring $\beta$-glucuronidase (GUS) gene. We found that a series fo modified medium ttained 100% shoot regeneration within 5 weeks after the preincubated explants on stage I medium were infected with Agrobacterium. Callus appeared at the cut edges of stem segments on stage II medium, mainly at the basal parts. Some explants started to form shoots after two to three weeks on stage III medium containing kanamycin (50 mg/L). When transferred to MS medium containing 200 mg/L kanamycin, 81% of the transformed shoots formed roots at the cut edge of the plantlets. In contrast, untrasformed shoots never rooted and became yellowish after few weeks under the same conditions. Southern and northern analysis indicated in vitro shoot regeneration on the callus derived from the potato explants, which were incubated with Agrobacteria. The regeneration cycle was shortened after the transformatin and finally the transformation efficiency was highly enhanced.

• Food Science and Preservation
• /
• v.15 no.1
• /
• pp.84-87
• /
• 2008

We used RT-PCR to measure housekeeping gene expression in mice fed GM and non-GM cabbage, in an effort to evaluate the risk of GM food to humans. After normalization of housekeeping gene levels, highly uniform expression may be seen in many organisms during various stages of development and under different environmental conditions. We assessed the expression of four genes in Chinese cabbage; these were Profilin, Tubulin-alpha (Tub-1), Heat-shock protein (Bchsp 17.6), and Ubiquitin conjugating enzyme (UBE). We measured the expression of four well-known housekeeping genes in mice: ${\beta}$-actin, (${\beta}$-act), ${\beta}$-2-microglobulin(B2m), Glyceraldehyde-3-phosphate dehydrogenase (GAPDH) and ${\beta}$-glucuronidase (Gus). Gene expression was measured in liver, stomach, small intestine, large intestine, kidney, and spleen of mice fed GM or non-GM cabbage. No significant expression differences were found.

• Korean Journal of Plant Resources
• /
• v.10 no.2
• /
• pp.107-113
• /
• 1997

Transformants of White Clover(Trifolium repens L.) were efficiently produced from immature seed derived callus cocultivated with Agrobacterium twnefaciens LBA4404 harboring plant binary vector. pBI121, using acetosyringone. The mean frequencies of transformants on the two kanamycin-containing media were 16 to 19% when the immature seed-derived calli were infected with bacteria cultured in the presence of 100$\mu$M acetosyringone compared with 7% in media without acetosyringone. Transgenic white clover was subject to molecular analysis for integration into plant nuclear genome and expression of $\beta$-glucuronidase(GUS) gene. PCR and Northern blot analyses demonstrated that GUS gene was integrated into white clover nuclear genome and expressed into its mRNA. The expression of GUS gene into its protein was confirmed by spectrophotometric assay of GUS activity.

• Journal of Plant Biotechnology
• /
• v.29 no.4
• /
• pp.223-228
• /
• 2002

We have developed a homemade particle inflow gun (PIG) system which has simple operation method, low price and high gene introduction efficiency into rice callus. Rice callus were inflowed with gold particles containing DNA of a plasmid, pIG121Hm, harboring intron GUS ($\beta$-glucuronidase) gene, NPTII gene and HPT gene. For optimal GUS transient expression, the effects of parameters on DNA delivery efficiency of the PIG system was investigated by scoring transient GUS expression. The highest number of blue spots was observed at 16 mM of spemidine and 1.5 M of calcium chloride, respectively. And the amount of gold particles required for the best GUD expression was 2 mg. Optimum GUS transient expression was observed at target distance of 12 cm and helium pressure of 3.5 bar (50 psi). Gene introduction efficiency of the PIG system was observed almost similar to that of the Biolistic Gun (Bio-Rad Company). Since PIG system is simple to operate and one doesn't need disposable accessaries, the PIG system can be easily applied to various replication experiments.

• Journal of Plant Biology
• /
• v.37 no.3
• /
• pp.371-380
• /
• 1994

To determine the patterns and the levels of expression of the cauliflower mosaic virus (CaMV 35S) promoter and the rice actin 1 (Act1) promoter in rice, transgenic rice plants containing CaMV 35S-$\beta$-glucuronidase (GUS) and Act1-GUS constructs were generated and examined by fluorometric and histochemical analyses. The fluorometric analysis of stably transformed calluses showed that the activity of the rice Act1 promoter was stronger than that of the CaMV 35S promoter in rice cells. In a histochemcial study of the transgenic rices, it was shown that the GUS activity directed by the CaMV 35S promoter was localized mainly in parenchymal cells of vascular tissues of leaves and roots and mesophyll cells of leaves. These results are similar to those of potato, a dicot plant. In contrast, rice plant transformed with Act1-GUS fusion construct revealed strong GUS activity in parenchymal cells of vascular tissue, mesophyll cells, epidermal cells, bulliform cells, guard subsidiary cells of leaves and most cells of the root, suggesting that the rice Act1 promoter is more constitutive than the CaMV 35S promoter. It was also confirmed that in both types of transgenic rice little or no staining was localized in metaxylen tracheary elements of vascular tissue from leaves or roots. These results indicate that the rice Act1 promoter can be utilized more successfully for expression of a variety of foreign gene in rice than the CaMV 35S promoter.

• Asian Journal of Turfgrass Science
• /
• v.15 no.1
• /
• pp.9-14
• /
• 2001

Callus formation and plant regeneration from the seeds of zoysiagrass cv. Zenith was tested on MS basal medium supplemented with various concentrations of 2,4-dichlorophenoxyacetic acid(2,4-D) and of several cytokinins. A concentration of 1mg/L 2,4-D on medium stimulated callus formation. In the presence of 5mg/L 2,4-D, addition of 1mg/L kinetin significantly enhanced callus formation and plant regeneration over 2,4-D alone. To transfer foreign DNA into turfgrass, parameters for the bombardment of embryogenic callus with the particle bombardment were partially optimized using transient expression assay of a $chimeric \beta$-glucuronidase(GUS) gene driven by the CaMV 35S promoter. GUS gene was strongly expressed at helium pressure 1,100 psi and 6~9cm target distance.

• Plant Biotechnology Reports
• /
• v.2 no.4
• /
• pp.267-270
• /
• 2008

We have successfully used the low-pressure BioWare gene gun, developed for gene transfer in animal cells, for plant tissues. The BioWare device is easy to manipulate. Just 50 psi helium pressure was sufficient to transfer foreign genes into the aleurone layer and embryo of maize without causing tissue damage in the impact area. As shown by expression signals from invasive histochemical ${\beta}-glucuronidase$ (GUS) activity, the foreign reporter gene expressed well in bombarded tissues. This successful GUS-transient expression extends the application of this low-pressure gene gun from animal cells to plant tissues.

• KSBB Journal
• /
• v.6 no.4
• /
• pp.385-388
• /
• 1991

Embryogenic cell suspension cultures of B. striata were established as transferred selected embryogenic callus into liquid medium. Protoplasts isolated from embryogenic cell suspensions were electroporated in buffered solutions containing plasmid DNA of pBI121. Transient GUS (beta-glucuronidase) activity measurement and selection for kanamycin resistent showed that expression of foreign genes and stable transformation were achieved. GUS transient gene expression was increased by increasing DNA concentration of pBI121 plasmid and affected by the level of the applied voltage. An optimal level of GUS activity was obtained after electroporation with a pulse of 200-300 voltage/1180 uF. Protoplast viability was up to the 80% at the optimal voltage.