• Korean Journal of Weed Science
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• v.32 no.1
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• pp.35-43
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• 2012

The objective of this research was to confirm the difference in physiological responses to environmental stresses such as chilling, high temperature, NaCl, and chemical stress (paraquat) in Protox inhibitor resistant-transgenic rice (MX, PX, and AP37) and its non-transgenic counterpart (WT). Transgenic and non-transgenic rice plants were exposed to a chilling temperature of $5^{\circ}C$ for 1 day or a high temperature of $45^{\circ}C$ for 4 days and allowed to recover at $25^{\circ}C$ for 6 days after the chilling treatment or 8 days after the high temperature treatment. Leaf injury, shoot fresh weight, porphyrin biosynthesis substances, and chlorophyll content were investigated in transgenic and non-transgenic rice at 6 days after 0.5% and 1% NaCl treatments or at 5 days after 0~300 ${\mu}M$ paraquat treatments. No significant difference in leaf injury and shoot fresh weight were observed between transgenic and non-transgenic rice during chilling and recovery. Plant height and shoot fresh weight were also similar between transgenic and non-transgenic rice during the high temperature and recovery period (0~5 days). However, plant height and shoot fresh weight in transgenic rice line MX and PX were lower than in non-transgenic rice at 6 days for recovery. Leaf injury, chlorophyll, and Mg-Proto IX ME contents had no significant difference between transgenic rice and non-transgenic rice after NaCl treatment, but Proto IX content for AP37 and shoot fresh weight for PX and AP37 in 0.5% NaCl treatment were significantly reduced compared with non-transgenic rice. There was no difference in leaf injury and shoot fresh weight when comparing transgenic rice and non-transgenic rice after paraquat treatment. Although transgenic rice and non-transgenic rice showed a little difference at a particular measurement period in certain environmental stresses, there was generally no difference in physiological responses between transgenic rice and non-transgenic rice.

• Journal of Plant Biotechnology
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• v.40 no.3
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• pp.135-140
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• 2013

A less simple approach developed for generation of marker-free transgenic plants is to select transformants without the use of selective marker genes. Some results about development of marker-free transgenic plants were obtained using a non-selective approach in several crops such as rice, potato and tobacco. However, the study did not provide evidence on detailed characterization of introduced gene on genome, a critical step for confirming the stable integration and transmission of a foreign gene. In this study, we evaluated structure and integration sites of transgene (mCry1Ac) in the transgenic Bt rice plants which were made via conventional Agrobacterium-mediated transformation by non-selective method. Structure and integration sites of transgene in these transgenic plants had similar fashion as those recovered under selection.

• Proceedings of the Korean Society of Crop Science Conference
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• 2017.06a
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• pp.165-165
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• 2017

Abiotic stress is one of the major serious limiting factors in rice (Oryza sativa) and caused rice production losses. It is important to precisely screen valuable genetic resources for improving stress tolerance and understanding tolerance mechanism to abiotic stresses. Because there are differences of experiment designs for screening of tolerant plant in several studies related to abiotic stress, this study has performed to provide the rapid and efficiency screening method for selection of tolerance rice to drought and salinity stresses. Two week-old rice seedlings that reached about three leaf stage were treated with drought and salinity stresses and examined tolerant levels with tolerant and susceptible control varieties, and transgenic plants. To determine the optimum concentration for the selection of drought and salinity condition, tolerant, susceptible and wild-type plants were grown under three soil moisture contents (5, 10 and 20% water contents) and three NaCl concentrations (100, 200 and 250 mM) for 10 days at seedling stage. 200 mM NaCl concentration and 5% moisture content soil were determined as the optimum conditions, respectively. The described methodologies in this study are simple and efficiency and might help the selection of drought and salinity tolerance plants at the 3,4-leaf-seedling stage.

• Journal of Plant Biotechnology
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• v.45 no.1
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• pp.63-70
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• 2018

Brazzein is the smallest sweet protein and was isolated from the fruit pulp of Pentadiplandra brazzeana Baillon, native to tropical Africa. From ancient times, the indigenous people used this fruit in their diet to add sweetness to their daily food. Brazzein is 500 to 2000 times sweeter than sucrose on a weight basis and 9500 times sweeter on a molar basis. This unique property has led to increasing interest in this protein. However, it is expensive and difficult to produce brazzein other than in its native growing conditions which limits its availability for use as a food additive. In this study, we report high production yields of, brazzein protein in transgenic rice plants. An ORF region encoding brazzein and driven by the $2{\times}CaMV\;35S$ promoter was introduced into rice genome (Oryza sativa Japonica) via Agrobacterium-mediated transformation. After transformation, 17 regenerated plant lines were obtained and these transgene-containing plants were confirmed by PCR analysis. In addition, the selected plant lines were analyzed by Taqman PCR and results showed that 9 T0 lines were found to have a single copy out of 17 transgenic plants. Moreover, high and genetically stable expression of brazzein was confirmed by western blot analysis. These results demonstrate that recombinant brazzein was efficiently expressed in transgenic rice plants, and that we have developed a new rice variety with a natural sweetener.

• Korean Journal of Breeding Science
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• v.42 no.5
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• pp.540-546
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• 2010

This study was conducted to understand the role of soybean pathogenesis-related 10 (GmPR10) gene in salt tolerance and to develop salt-tolerant rice using GmPR10 cDNA. GmPR10 transgene was expressed constitutively in the shoot and root of the $T_1$ transgenic rice plants. Interestingly, however, the levels of the transgene expression were increased temporally up to over four- to five-fold in the shoot and root by 125 mM NaCl treatment, peaking at six hours after the treatment and decreasing thereafter. Electrolyte leakage of leaf cells under 125 mM NaCl treatment was lower in all the transgenic lines than in the control variety, Dongjin-byeo. Ability of seedlings to recover from 125 mM NaCl treatment for two weeks was higher in the transgenic plants than in the control plants. These results demonstrated that GmPR10 had function to increase cell integrity and promote growth under the saline stress imposed by NaCl. The transgenic line GmPR10-3 which showed highest ability to recover from the saline stress could be used as a potential source for salt tolerance in rice breeding programs.

• Proceedings of the Korean Society of Crop Science Conference
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• 2017.06a
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• pp.168-168
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• 2017

Drought conditions during cultivation reduce agricultural production yield less than a theoretical maximum yield under normal condition. Plant specific NAC transcription factors in rice are known to play an essential roles in stress resistance transcriptional regulation. In this study, we report the rice (Oryza sativa L japonica) NAM, AFTF and CUC transcription factor OsNAC17, which is predominantly induced by abiotic stress in leaf, was contribute to the drought tolerance mediated reactive oxygen species (ROS) in transgenic rice plants. Constitutive (PGD1) promoter was introduced to overexpress OsNAC17 and produced the transgenic PDG1:OsNAC17. Overexpression of OsNAC17 throughout the whole plant improved drought resistance phenotype at the vegetative stage. Morphological characteristics such as grain yield, grain filling rate, and total grain weight improved by 22~64% over wild type plants under drought conditions during the reproductive stage. The improved drought tolerance in transgenic rice was involved in reducing stomatal density up to 15% than in wild type plants and in increasing reactive oxygen species-scavenging enzyme. DEG profiling experiment identified 119 up-regulated genes by more than twofold (P<0.01). These genes included UDP-glycosyltransferase family protein, similar to 2-alkenal reductase (NADPH-dependent oxireductase), similar to retinol dehydrogenase 12, Lipoxygenase, and NB-ARC domain containing protein related in cell death. Furthermore, OsNAC17 was act as a transcriptional activator, which has an activation domain in C-terminal region. These result demonstrate that the overexpression of OsNAC17 improve drought tolerance by regulating ROS scavenging enzymes and by reducing stomatal density

• The Plant Pathology Journal
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• v.32 no.6
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• pp.552-562
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• 2016

Pathogenesis-related proteins play multiple roles in plant development and biotic and abiotic stress tolerance. Here, we characterize a rice defense related gene named "jasmonic acid inducible pathogenesis-related class 10" (JIOsPR10) to gain an insight into its functional properties. Semi-quantitative RT-PCR analysis showed up-regulation of JIOsPR10 under salt and drought stress conditions. Constitutive over-expression JIOsPR10 in rice promoted shoot and root development in transgenic plants, however, their productivity was unaltered. Further experiments exhibited that the transgenic plants showed reduced susceptibility to rice blast fungus, and enhanced salt and drought stress tolerance as compared to the wild type. A comparative proteomic profiling of wild type and transgenic plants showed that overexpression of JIOsPR10 led to the differential modulation of several proteins mainly related with oxidative stresses, carbohydrate metabolism, and plant defense. Taken together, our findings suggest that JIOsPR10 plays important roles in biotic and abiotic stresses tolerance probably by activation of stress related proteins.

• Journal of Plant Biotechnology
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• v.34 no.2
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• pp.145-152
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• 2007

Lactoferrin is an 80-kDa iron-binding glycoprotein known to exert many biological activities, such as facilitating iron absorption and having antimicrobial and anti-inflammatory effects. Rice can be a useful target for edible food plants to introduce human lactoferrin, because it has lower allergenicity and is likely to be safer than microorganisms or transgenic animals. A cDNA fragment encoding human lactoferrin (HLF) driven by the maize polyubiquitin promoter, along with herbicide resistance gene (bar) driven by CaMV 35S promoter, was introduced into rice (Oryza sativa L. cv. Dong Jin) using the Agrobacterium -mediated transformation system. Putative transformants were initially selected on the medium containing bialaphos. The stable integration of the bar and HLF genes into transgenic rice plants was further confirmed through polymerase chain reaction (PCR) and Southern blot analyses. The expression of the full length HLF protein from various tissues such as grains and young leaves of transgenic rice was verified by Western blot analysis. Analysis of progeny also demonstrated that introduced genes were stably inherited to the next generation at the Mendelian fashion.

• Proceedings of the Botanical Society of Korea Conference
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• 1994.07a
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• pp.137-140
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• 1994

• Journal of Life Science
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• v.14 no.4
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• pp.644-649
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• 2004

During plant development, active gibberellins (GAs) control many aspects of plant growth and development including seed germination, stem elongation, flower induction, anther development and seed growth. To understand the biosynthesis and functional role of active GAs in high plants, this study investigated GA 3$\beta$-hydroxylase gene en-coding $GA_1$ and$GA_4$ catalizing last step in GA biosynthetic pathway. The antisense GA 3$\beta$-hydroxylase gene was inserted into expression vector, pIG121-Hm. Calli derived from mature seeds of rice (Oryza satiiva L. cv. Donjinbyeo) were co-cultivated with Agrohacterium tumefaciens EHA101 earring a pIG121-Hm containing hygromycin resistance ($Hyg^r$) and antisense GA 3$\beta$-hydroxylase gene. Seventeen transgenic plants obtained inhibiting GA 3$\beta$-hydroxylase. Transgenic plants had shorter plant height more than that of the Dongjinbyeo. Stable integration of antisense GA 3$\beta$-hydroxylase gene was confirmed by polymerase chain reaction of genomic DNA isolated from the leaf organs of the $T_o$ generation.