• Plant Biotechnology Reports
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• v.2 no.1
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• pp.41-46
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• 2008

Salinity stress is a major limiting factor in cereal productivity. Many studies report improvements in salt tolerance using model plants, such as Arabidopsis thaliana or standard varieties of rice, e.g., the japonica rice cultivar Nipponbare. However, there are few reports on the enhancement of salt tolerance in local rice cultivars. In this work, we used the indica rice (Oryza sativa) cultivar BR5, which is a local cultivar in Bangladesh. To improve salt tolerance in BR5, we introduced the Escherichia coli catalase gene, katE. We integrated the katE gene into BR5 plants using an Agrobacterium tumefaciens-mediated method. The introduced katE gene was actively expressed in the transgenic BR5 rice plants, and catalase activity in $T_1$ and $T_2$ transgenic rice was approximately 150% higher than in nontransgenic plants. Under NaCl stress conditions, the transgenic rice plants exhibited high tolerance compared with nontransgenic rice plants. $T_2$ transgenic plants survived in a 200 mM NaCl solution for 2 weeks, whereas nontransgenic plants were scorched after 4 days soaking in the same NaCl solution. Our results indicate that the katE gene can confer salt tolerance to BR5 rice plants. Enhancement of salt tolerance in a local rice cultivar, such as BR5, will provide a powerful and useful tool for overcoming food shortage problems.

• Journal of Plant Biotechnology
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• v.45 no.4
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• pp.364-368
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• 2018

The R2R3-type protein IbMYB1 transcription factor is a key regulator for anthocyanin biosynthesis in the storage roots of sweet potatoes. It was previously demonstrated that the IbMYB1 expression stimulates anthocyanin pigmentation in tobacco leaves, arabidopsis and storage roots of sweet potatoes. In this study, we generated the transgenic potato plants that express the IbMYB1 genes, which accumulated high levels of anthocyanins under the control of either the tuber-specific patatin (PAT) promoter or oxidative stress-inducible peroxidase anionic 2 (SWPA2) promoter. The PAT-MYB1 transgenic lines exhibited higher anthocyanin levels in the tuber than the empty vector control (EV) or SWPA2-MYB1 plants. When combined, our results indicated that overexpression of the IbMYB1 is a highly promising strategy for the generation of transgenic plants with enhanced tissue specific anthocyanin production.

• Journal of Life Science
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• v.17 no.9 s.89
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• pp.1177-1181
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• 2007

Calmodulin (CaM), a ubiquitous calcium-binding protein, regulates diverse cellular functions by modulating the activity of a variety CaM-binding proteins (CaMBPs). Because eukaryotes have multiple CaMBPs, it is important to isolate and characterize them in different tissues and conditions. So far a number of CaMBPs have been identified through classical screening methods. Many classes of proteins have been predicted to bind CaMs based on their structural homology with already known targets. In an effort to develop a method for large-scale analysis of CaMBPs in Arabidopsis, we have generated a transgenic plants overexpressing AtCaM2-GFP. We performed protein pull-down assay to test whether exogenously expressed AtCaM2-GFP proteins can interact with CaMBPs. The exogenously expressed AtCaM2-GFP could strongly interact with a CaMBP, AS1 protein. This result suggests that AtCaM2-GFP in transgenic plants may interact with many CaMBPs in plant cell. Therefore, we will be able to isolate kinds of CaMBPs by using these transgenic plants in many different tissue and environments.

• Journal of Plant Biotechnology
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• v.36 no.1
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• pp.59-63
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• 2009

Calcium ion ($Ca^{2+}$) is thought to play the important role as a second messenger for signal transduction that results in various physiological responses to cope with developmental programs and environmental changes in plant. In plant cells, the central vacuole functions as a major calcium store, which is important for both signal transduction and preventing cytotoxicity. Although there is evidence for the biochemical characterizations of a calmodulin-regulated $Ca^{2+}$-ATPase (ACA11) localized to vacuole membrane, the biological function to ACA11 in plant has not been verified. In this study, we show that the cell death as the hypersensitive response (HR) in mature leaves is induced in transgenic plant of a vacuole ACA-type $Ca^{2+}$-ATPase, ACA11. Evidence that cell death phenotype is the result of ACA11 gene silencing is provided by Western blot assay using membrane fraction proteins extracted from transgenic plant. The 3, 3'-diaminobenzidine (DAB) staining study provides that the cell death is caused by the increase of reactive oxygen species (ROS) in mature leaves of transgenic plants.

• Journal of Plant Biotechnology
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• v.5 no.3
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• pp.137-142
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• 2003

The morphology of the leaves and the flowers of angiosperms exhibit remarkable diversity. One of the factors showing the greatest variability of leaf organs is the leaf index, namely, the ratio of leaf length to leaf width. In some cases, different varieties of a single species or closely related species can be distinguished by differences in leaf index. To some extent, the leaf index reflects the morphological adaptation of leaves to a particular environment. In addition, the growth of leaf organs is dependent on the extent of the expansion of leaf cells and on cell proliferation in the cellular level. The rates of the division and enlargement of leaf cells at each stage contribute to the final shape of the leaf, and play important roles throughout leaf development. Thus, the control of leaf shape is related to the control of the shape of cells and the size of cells within the leaf. The shape of flower also reflects the shape of leaf, since floral organs are thought to be a derivative of leaf organs. No good tools have been available for studies of the mechanisms that underlie such biodiversity. However, we have recently obtained some information about molecular mechanisms of leaf morphogenesis as a result of studies of leaves of the model plant, Arabidopsis thaliana. For example, the ANGUSTIFOLIA (AN) gene, a homolog of animal CtBP genes, controls leaf width. AN appears to regulate the polar elongation of leaf cells via control of the arrangement of cortical microtubules. By contrast, the ROTUNDIFOLIA3 (ROT3) gene controls leaf length via the biosynthesis of steroid(s). We provide here an overview of the biodiversity exhibited by the leaf index of angiosperms. Taken together, we can discuss on the possibility of the control of the shapes and size of plant organs by transgenic approaches with the results from basic researches. For example, transgenic plants that overexpressed a wildtype ROT3 gene had longer leaves than parent plants, without any changes in leaf width. Thus, The genes for leaf growth and development, such as ROT3 gene, should be useful tools for the biodesign of plant organs.

• Proceedings of the Korean Society of Plant Biotechnology Conference
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• 2003.04a
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• pp.49-55
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• 2003

The morphology of the leaves and the flowers of angiosperms exhibit remarkable diversity. One of the factors showing the greatest variability of leaf organs is the leaf index, namely, the ratio of leaf length to leaf width. In some cases, different varieties of a single species or closely related species can be distinguished by differences in leaf index. To some extent, the leaf index reflects the morphological adaptation of leaves to a particular environment. In addition, the growth of leaf organs is dependent on the extent of the expansion of leaf cells and on cell proliferation in the cellular level. The rates of the division and enlargement of leaf cells at each stage contribute to the final shape of the leaf, and play important roles throughout leaf development. Thus, the control of leaf shape is related to the control of the shape of cells and the size of cells within the leaf. The shape of flower also reflects the shape of leaf, since floral organs are thought to be a derivative of leaf organs. No good tools have been available for studies of the mechanisms that underlie such biodiversity. However, we have recently obtained some information about molecular mechanisms of leaf morphogenesis as a result of studies of leaves of the model plant, Arabidopsis thaliana. For example, the ANGUSTIFOLIA (AN) gene, a homolog of animal CtBP genes, controls leaf width. AN appears to regulate the polar elongation of leaf cells via control of the arrangement of cortical microtubules. By contrast, the ROTUNDIFOLIA3 (ROT3) gene controls leaf length via the biosynthesis of steroid(s). We provide here an overview of the biodiversity exhibited by the leaf index of angiosperms. Taken together, we can discuss on the possibility of the control of the shapes and size of plant organs by transgenic approaches with the results from basic researches. For example, transgenic plants that overexpressed a wild-type ROT3 gene had longer leaves than parent plants, without any changes in leaf width. Thus, The genes for leaf growth and development, such as ROT3 gene, should be useful tools for the biodesign of plant organs.

• Proceedings of the Korean Society of Crop Science Conference
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• 2017.06a
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• pp.100-100
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• 2017

FT is one of the major floral activator in plant flowering. FT determines the changing point of time from vegetative stage to reproductive stage. To understand the role of FT homologs in short-day plant soybean, we identified 10 soybean FT homologous genes and named GmFTs. We figured out that 10 GmFT genes were further categorized into three subclades through phylogenetic analysis. Expression analysis of GmFT genes indicated that they might have different functions in photoperiod-dependent soybean flowering. Most of GmFTs, for example, GmFT2a, GmFT2b, GmFT5a and GmFT6 mainly expressed in soybean leaves at short-day condition. However, interestingly GmFT1a and GmFT4 represented opposite expression pattern to other GmFTs. Arabidopsis transgenic plants overexpressing GmFT2a and GmFT5a exhibited extremely early flowering. In contrast, overexpression of GmFT4 delayed flowering of Arabidopsis transgenic plants. The results suggest that GmFT4 has antagonistic role to other GmFTs in soybean flowering. Interestingly, mRNA level of GmFT2a is higher in early flowering soybean accessions than in late flowering ones. Moreover, the highest point of mRNA level of GmFT2a showed the positive correlation with the timing of flowering of soybean accessions. But that of GmFT4 showed opposite pattern. Here, we report that soybean FT homologs might acquire different functions in photoperiod-dependent flowering through the functional diversification during evolution.

• Journal of Plant Biotechnology
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• v.39 no.4
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• pp.253-260
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• 2012

On the basis of the reported agriculturally valuable phenotypes resulted from ectopic overexpression of Arabidopsis vacuolar $H^+$-PPase (AVP1), we generated the Chinese cabbage lines expressing AVP1 which then subjected to salt stress to determine the AVP1 expression if it consistently confers the capability for increasing biomass and enhancing tolerance to salinity in other species. Collectively, here we demonstrate that the transgenic young plants show more vigorous growth and higher tolerance to salt stress than wild-type ones. Increased biomass phenotype by AVP1 expression was supported by comparing fresh and dry weights of transgenic and wild type plants grown under normal condition, while higher salt tolerance trait was confirmed by tracing the kinetics of photosystem II quantum yield and DAB-staining under gradually intensified salt stress induced by MS salt or NaCl, followed by normal condition.

• Journal of Plant Biotechnology
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• v.36 no.4
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• pp.407-414
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• 2009

A cDNA clone encoding phytocystatin was isolated from Brassica rapa seedlings, through rapid amplification of cDNA ends (RACE). This gene (name as Brcpi1; GenBank accession no.: EF079953) had a total length of 881 bp with an open reading frame of 609 bp, and encoded predicted polypeptide of 203 amino acid (aa) residues including a putative N-terminal signal peptide. Other relevant regions found its sequence included the G and PW conserved aa motifs, and the consensus LARFAV sequence for phytocystatins and the reactive site QVVAG. The BrCPI1 protein shared 95, 94, 81, 80 and 78% identity with other CPI proterins isolated from Brassica oleracea (BoCPI-1), Arabidopsis thaliana (AtCY SB), Glycine max (GmCPI), Oryza sativa (OsCYS-2) and Zea may (ZmCPI) at amino acid level, respectively. Southern blot analysis showed that Brcpi1 was a low copy gene. Expression pattern analysis revealed that Brcpi1 was a tissue-specific expressing gene during reproductive growth and strongly expressed at mature seedling stages. Furthermore, overexpression of Brcpi1 in transgenic Arabidopsis was enhanced tolerance to salt and cold stresses. Meanwhile the juvenile seedling of Brcpi1 transgenic plants was not affected by various concentrations ABA in MS medium. Taken together, the results showed that Brcpi1 functioned as a cysteine protease inhibitor and it exhibited a protective agent against diverse types of abiotic stress, which induced this gene in a tissue- and stress-specific manner.

• Plant Biotechnology Reports
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• v.4 no.1
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• pp.53-59
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• 2010

A specific deleted version of ARABIDOPSIS RESPONSE REGULATOR1 (ARR1) lacking the signal receiver domain (1.152 amino acids)-coding sequence, referred to as $ARR1{\Delta}DDK$, was amplified using Arabidopsis thaliana cDNA prepared from adult leaves and transferred into the genome of Nicotiana tabacum cv. Samsun under the transcriptional control of a ${\beta}$-estradiol-inducible expression system. The ectopic expression of $ARR1{\Delta}DDK$ affected the morphology of transgenic seedlings and their segments in vitro. In the presence of an inducer, ${\beta}$-estradiol, ectopic expression of $ARR1{\Delta}DDK$ induced only the formation of soft, pseudo-bulbous tissue in the root tip region of intact seedlings, which appeared similar to callus generated on a hypocotyl segment in the presence of 2,4-D and 6-benzyladenine (BA), both at $1\;{\mu}M$. Those callus tissues on the root tip region could not generate shoots unless $1\;{\mu}M$ BA was supplied. In segment culture, ectopic expression of $ARR1{\Delta}DDK$ induced calluslike tissue around the cut-end of cotyledon and hypocotyl segments with occasional shoot formation, suggesting that the expression of $ARR1{\Delta}DDK$ could substitute for the effects of cytokinin on these segments. Additionally, treatment with only ${\beta}$-estradiol induced NtWUS, a WUS ortholog in tobacco, which was detected during the process of callus tissue formation in the root tip region and also in cotyledon or hypocotyl segments. These findings suggest that the NtWUS might be associated in the transdifferentiation process caused by the functional regulation of $ARR1{\Delta}DDK$ in transgenic tobacco seedlings.