Since global climate changes drastically, pre-harvest sprouting (PHS) is expected to pose serious problems in rice production. CBL-interacting serine/threonine protein kinases (CIPKs) have been implicated to play important role in regulating various abiotic stresses such as cold, salinity and drought. In this study, to understand the function of this gene under pre-harvest sprouting in rice, a cDNA clone encoding CBL-interacting protein kinase 15 was isolated from rice flowers. We constructed a recombinant vector carrying the CIPK15 under the control of the CaMV 35S promoter and Tnos terminator and transformed into rice using Agrobacterium tumefaciens. Insertion of the gene was verified in transformants using HPT resistance test and genomic PCR. Transcriptional profiling using tissues of wild type, Gopum, revealed expression of the gene in whole plant tissues with level of expression highest in the seeds suggesting possible role in dormancy. Comparative expression analysis of the gene in transgenic and wild type through semi-quantitative RT-PCR and real-time PCR showed higher expression in transgenic rice lines. Moreover, screening in the mist chamber showed overexpression lines that were resistant to the PHS. This result suggests the involvement of CIPK15 in the regulation of pre-harvest sprouting.

꾸지뽕 열매의 부가가치를 증대하기 위해 꾸지뽕 발효식 초를 제조하고 그의 발효조건을 확립하였다. 전통발효식품 으로부터 초산내성, 초산 고생산능, ethanol 내성 및 아황산 내성이 우수한 49종의 초산 균주를 분리하였고, 16S rRNA 유전자 염기서열의 해독 결과, Acetobacter indonesiensis, A. cerevisiae, A. orientalis, A. tropicalis, A. fabarum, A. pasteurianus 및 A. syzygii으로 동정되었다. 이들 중 GRAS 균주인 A. pasteurianus SCMA5와 SCMA6를 발효 균주로 최종 선정하였다. 최적 발효는 꾸지뽕 열매 함량이 40%(v/v)인 즙액과 5%(v/v) ethanol을 첨가하여 25℃에서 72시간 발효가 가장 적절하였다. 관능평가 결과, SCMA06 균주를 적용한 발효액의 선호도가 SCMA05 균주를 적용한 발효액보다 높았다. SCMA06 균주를 사용한 발효식초에서 항산화 능력을 측정하는 DPPH 라디컬 소거활성의 경우 대조구에 비해 53.02±0.78%이상 높게 나타났고, 항당뇨 능력을 측정하는 AGI활성은 발효 72시간에 91.40±2.43% 저해능을 보여 시판중인 acarbose보다 활성이 높았다. 이번 연구는 꾸지뽕 열매를 활용한 발효식초 제조를 위한 산업화 연구에 기여할 수 있을 것이다.

Secondary plant metabolites undergo several modification reactions, including glycosylation and physiological functions. Glycosylation, which is mediated by UDP-glycosyltransferase (UGT), plays a role in the storage of secondary metabolites and in defending plants against stress. In this study, a UDP-glucosyltransferase cDNA was isolated from Brassica rapa hereinafter referred to as BrUGT. It has a full-length cDNA of 1,236 bp that contains a single open reading frame of 834 bp which encodes a polypeptide of 277 amino acid residues with a calculated mass of 31.19 kDa. BLASTX analysis hits a catalytic domain of glycos_transf_1 super family (c112012) that belongs to the glycosyltransferases group 1 with tetratricopeptide (TPR) regions. UGT gene expression analysis showed high mRNA transcripts in pistil, followed by petal, seed and calyx of flower in Brassica rapa. Furthermore, we constructed a recombinant pFLCIII vector carrying the BrUGT gene under the control of ubiquitin promoter and NOS terminator and transformed into rice using Agrobacterium tumefaciens. The UGT overexpressing rice lines were then characterized at the physiological and molecular levels. To further understand the biological function of BrUGT, transcriptional profiling of the gene in transgenic rice lines under cold, salt, PEG, H2O2, ABA and drought stress condition is underway.

Fortification with vitamins in crops like rice is a continuing endeavor for geneticists and rice breeders. Tryptophan is one of the essential amino acids needed in human diet. In this study, we developed rice mutant lines using ethyl methane sulfonate (EMS) treatment in Korean cv. Donganbyeo and candidate rice lines were selected by insensitivity to the tryptophan analog, 5-methyltryptophan. One of the mutants has a 20-25 fold higher tryptophan level in mature seeds than wild type. To identify the mutations in anthranilate synthase genes, OASA1 and OASA2 sequences were generated. Moreover, mRNA expression levels of tryptophan biosynthesis related genes were examined. To further qualify the tryptophan fortification in rice, comparative assessment of cooking and eating quality was conducted with mutant lines and wild type. The moisture, viscosity, taste quality, protein content, amylose content and amino acid composition were similar with wild type. However, tryptophan contents in the mutant lines were higher than wild type as we targeted. The mutation present in AS gene of 5MT resistant rice may prove useful for the generation of crops with increased tryptophan contents and the mutation differences in AS sequences can be used for selection of mutant lines with high tryptophan level from large population.

There is a great consideration on rice eating quality aside from improving its tolerance to various stresses. High yielding and pest and disease tolerant rice is highly desirable but it is more commercially important if it also has a high eating quality. There are various factors contributing to the good eating quality of rice. This study focuses on modifying the expression of GBSS1 genes which are responsible for amylopectin and amylose synthesis in rice by using RNAi and antisense techniques. We have developed 40 transgenic plants with RNAi-GBSS1 gene and 60 transgenic lines with antisense-GBSS1 gene. The transgenic plants show diverse amylose contents in rice seed. We selected candidate lines according to PCR, RNA expression and amylose contents. A semi-quantitative RT-PCR was carried out to measure the expression level of GBSS1 gene at several time points after the flowering of transgenic plants. The expression level of GBSS1 gene in rice grains decreases over time and the mRNA expression among the transgenic plants were lower compare to its wild type. In the SEM analysis, the starch granule of wild type Gopumbyeo has very large structures accompanied with small ones around the area. However, the starch structures in transgenic plants were smaller and more uniform in size and shape throughout the viewing area

An increasing preference for good eating quality of rice among consumers has become one of the important considerations in rice breeding. Amylose content of starch is one of the important factors of rice eating quality. Amylose composition is determined by the relative activity of soluble starch synthase (SSS) and granule-bound starch synthase (GBSS). This study focuses on modifying the expression of SSS1 gene which is responsible for amylopectin and amylose synthesis in rice by using RNA interference (RNAi) and antisense technology. The transgenic rice plants showed various amylose content (9-17%) in rice seed. Candidate rice lines were selected according to PCR, RNA expression and amylose contents analyses. A semi-quantitative RT-PCR was carried out to determine the expression level of SSS1 gene at several time points after the flowering of transgenic plants. Downregulation of SSS1 gene in transgenic rices was evident in the decreasing expression in rice grains over time. Accordingly, SEM micrographs analysis revealed uniform size with smooth curves starch granules in downregulation rice lines, in contrast with the non-uniform granules in wild type.

UDP-glucose 4-epimerase (UGE) catalyzes the reversible conversion of UDP-glucose to UDP-galactose. To understand the biological function of UGE from Brassica rapa, the gene hereinafter referred to as was cloned and overexpressed into Japonica rice cv. Gopum. Transcriptional profiling showed that the is specific to stem of rice plant. Morphological evaluation of the overexpression lines revealed altered phenotype characters particularly in panicle length, number of productive tillers and filled spikelets which account for an increase in yield. This remarkable agronomic performance was ascribed to higher photosynthetic rate complemented with higher CO2 assimilation. Interestingly, BrUGE1 did not only improve plant fitness under optimal condition but also under water deficit stress. The enhanced drought tolerance may be due to the induction of soluble sugar which may act as osmolyte to compensate dehydration during drought stress.

Since global climate changes drastically, pre-harvest sprouting (PHS) is expected to pose serious problems in rice production. CBL-interacting serine/threonine protein kinases (CIPKs) have been implicated to play important role in regulating various abiotic stresses such as cold, salinity and drought. In this study, to understand the function of this gene under pre-harvest sprouting in rice, a cDNA clone encoding CBL-interacting protein kinase 15 (CIPK15) was isolated from rice flowers. This gene is 2,818 bp long with 1,332 bp coding region that encodes a polypeptide of 443 amino acids. We constructed a recombinant vector carrying the OsCIPK15 under the control of the CaMV 35S promoter and Tnos terminator and transformed into rice using Agrobacterium tumefaciens. Insertion of the gene was verified in transformants using HPT resistance test and genomic PCR. Transcriptional profiling using tissues of wild type, Gopum, revealed expression of the gene in whole plant tissues with level of expression highest in the seeds suggesting possible role in dormancy. Comparative expression analysis of the gene in transgenic and wild type through semi-quantitative RT-PCR and real-time PCR showed higher expression in transgenic rice lines. Moreover, screening in the mist chamber showed overexpression lines that were resistant to the PHS. This result suggests the involvement of OsCIPK15 in the regulation of pre-harvest sprouting.

In spite of the overwhelming number of cysteine proteases in plants, only a few were substantially investigated. Papain-like cysteine proteases (PLCPs) are commonly implicated to disease immunity in some key pathosystems in plants, such as in tomato – Cladosporium fulvum, potato/tomato – phytopthora infestans, and Arabidopsis – Ralstonia solanacearum, among the few others. This study demonstrates the function of cysteine protease gene cloned form Brassica rapa (BrCP) related to resistance to Xanthomonas oryzae pv. oryzae in transgenic rice lines. The cysteine protease-encoding full-length cDNA was identified and characterized using web-based tools. The gene is 2,267 bp in size with an open reading frame of 1,365 bp that encodes predicted polypeptide of 455 amino acids. Blast analysis of the conserved domain of the gene confirmed its affinity to Peptidase_CIA family. Full-length cDNA of PLCP in Brassica rapa was then cloned and co-overexpressed in rice with HPT marker. Introgression of the gene was confirmed in the transformants through genomic PCR assay. RT-PCR analysis showed that the gene was constitutively expressed and present in all tissues. The overexpression rice lines exhibited an enhanced resistance when screened with four Korean Xoo isolates.

Glutamine synthetase (GS) is an enzyme that plays an essential role in the metabolism of nitrogen by catalyzing the condensation of glutamate and ammonia to form glutamine. Exposure of plants to cadmium (Cd) has been reported to decrease GS activity in maize, pea, bean, and rice. To better understand the function of the GS gene under Cd stress in rice, we constructed a recombinant pART vector carrying the GS gene under the control of the CaMV 35S promoter and OCS terminator and transformed using Agrobacterium tumefaciens. We then investigated GS overexpressing rice lines at the physiological and molecular levels under Cd toxicity. The GS activity along with mRNA expression were found higher in transgenic than in wild type plants. And this is validated by the low malondialdehyde contents observed 10 days after treatment. GS overexpression in rice resulted in the modulation of expression of enzymes responsible for membrane peroxidation, which may result in the sudden death of plants. Our results thus describe the features of a transgenic rice plants with enhanced tolerance to Cd toxicity.

Amylopectin composition is determined by the relative activity of soluble starch synthase (SSS) and granule-bound starch synthase (GBSS). Soluble starch synthase and starch branching enzymes are major determinants for the synthesis of amylopectin while GBSS1 is responsible for amylose synthesis in vivo. The formers are made of linear and branched molecules and the latter is composed of highly branched molecules. To increase the palatability of rice, down-regulation of amylose synthesis by antisense and RNA interference (RNAi) could be excellent and powerful tools for controlling the starch composition which is responsible for grain eating quality. The goal of this study is to generate breeding lines with lower amylose content relative to its wild type. This study also reports the results of the two down-regulating technology in lowering the amylose content of rice grain. Furthermore, this study elucidates the effect of using antisense and RNAi for SSS1 and GBSS1.

UDP-glucose 4-epimerase catalyzes the reversible conversion of UDP-glucose to UDP-galactose. The gene, named BrUGE1, isolated from a Chinese cabbage composes of a total length of 1,328 bp that contains a single open reading frame (ORF) of 1,056 bp which encodes a polypeptide of 351 amino acid residues with a calculated mass of 39.0 kDa. Expression analysis showed that BrUGE1 is tissue specific and highly expressed in stem of rice plant. Interestingly, BrUGE1 mRNA was highly accumulated by drought stress with significantly higher amount of soluble sugar. Morphological evaluation showed an increase in yield and yield components compared to the wild type. Moreover, a better growth performance on galactose as well as higher UGE1 expression was observed in transgenic rice lines than in wild type. In the Ubi-1::BrUGE1 lines, the increase of UGE1 expression was apparently sufficient to overcome the toxic effects of galactose. Taken together, the Ubi-1::BrGUE1 rice lines increased yield probably by increasing the rate of filled grains. The enhanced drought tolerance may be due to the induction of soluble sugar which may act as osmolyte to compensate dehydration during drought stress.

Bacterial blight is a serious problem of rice in irrigated and rainfed lowlands. It is caused by Xanthomonas oryzae pv. oryzae (Xoo) which is represented by many pathotypes, making it difficult to control. Plant proteases are important players in immunity acting either in the execution of attack, in signaling cascade or in perception of invader. This study demonstrates the response of cysteine protease (CP) upon interaction with the pathogen. The cysteine protease encoding full-length cDNA was identified and characterized using web-based tools. Conserved domain of the gene revealed its affinity to Peptidase_CIA family. The full-length cDNA of CP in Brassica rapa was then cloned and overexpressed in rice. Insertion of gene was verified in the transformants through PCR assay. Spatiotemporal expression of the gene was performed in transgenic rice. To evaluate the resistance of CP-overexpression lines to Xoo, transgenic plants were inoculated with two races of Xoo. In planta analysis of enzymatic activity of CP was also performed before and after infection by the pathogen.

A cDNA clone encoding CBL-interacting protein kinase 1 (CIPK1) was isolated from Chinese cabbage seedlings. The gene, BrCIPK1 consisted of 1,982 bp long with 216 bp of the 5’-untranslated region (UTR), 1,509 bp of the coding region and 257 bp of the 3’-UTR. It is highly conserved CBL-interacting module with absolutely conserved domain among the 15 amino acid NAF domain of the 15 related genes. Southern blot analysis showed a single copy number. BrCIPK1 gene was localized in the cytoplasm and peripheral region in the plant cell which is highly expressed in seedling of rice and in the shoot and pistil of Arabidopsis. Analyses of gene expression on Ubi-1::BrCIPK1 rice lines was differentially accumulated by cold, salinity and drought, indicating its biological roles in the multiple stress response pathways in plants. Further, the expression of BrCIPK1 is hijacked by rice calcineurin-B-like protein (OsCBL5). Moreover, mRNA expression of P5CS1, a gene responsible for proline biosynthesis is regulated by the BrCIPK1 during abiotic stresses resulting to improved accumulation of proline. The interaction of BrCIPK1 with OsCBL5 along with the regulation of P5CS1 explained the enhanced tolerance of transgenic rice. This gene could be used in the development of rice varieties with enhanced tolerance to abiotic stresses.

Regulations in the EU, Japan, Korea, etc. require that foods and feeds made of or derived from genetically modified organisms (GMOs) should be approved and labeled according to a threshold. Recently, disease resistant transgenic rice was developed in Korea, which resulted from the transformation events involving choline kinase gene, OsCK1. In order to monitor unintended release of the developed GM rice in the near future, as well as to meet GM-labeling requirements, the development of a reliable method for detection of disease resistant GM rice is requisite. Here, specific primer pairs for the detection of GMO was designed on the basis of a introduced gene and the flanking junction sequences between a plant DNA and a integrated gene construct, and also SPS gene was used as an endogenous reference material. Specificities of all designed primers were tested through qualitative PCRs. Clearly, target specific amplicons could be detected from disease resistant GM rice event. In addition, the limits of detection (LOD) using the event-specific primers were approximately 0.1% for the disease resistant GM rice line. This result indicated that the developed detection method is suitable for the traceability of disease resistant GM rice, because of using the primer specifically corresponded to the junction site between plant genomic DNA and inserted DNA. Keywords: genetically modified organisms, disease resistant GM rice, PCR detection, event-specific primer

UDP-glucose 4-epimerase (UGE) catalyzes the reversible conversion of UDP-glucose to UDP-galactose. The gene, named BrUGE1, isolated from a Chinese cabbage had a total length of 1,328 bp that contains a single open reading frame (ORF) of 1,056 bp which encodes a polypeptide of 351 amino acid residues with a calculated mass of 39.0 kDa. Sequence analysis of BrUGE1 protein has the characteristic of an active site tetrad and NAD-binding motif (typically TGXXGXXG) of the extended short chain dehydrogenase/ reductase (SRD) superfamily. Expression analysis showed that BrUGE1 is tissue specific and highly expressed in stem of rice plant. Interestingly, BrUGE1 mRNA was highly accumulated by drought stress with significantly higher amount of soluble sugar. Morphological evaluation showed an increase in yield by 27%. Panicle length, number of productive tillers/hill, and filled spikelets were significantly increased by 17~20% compared to the wild type Gopum. Moreover, the growth of the wild type Gopum seedlings on galactose was increasingly inhibited with a decrease in UDP-glc epimerase 1 expression compared to the transgenic rice lines. In the Ubi-1::BrUGE1 lines, the increase of UDP-glc epimerase 1 expression was apparently sufficient to overcome the toxic effects of galactose. Taken together, the Ubi-1::BrGUE1 rice lines increased yield probably by increasing the rate of filled grains. The enhanced drought tolerance may be due to the induction of soluble sugar which may act as osmolyte to compensate dehydration during drought stress.

MYB-like domain (MLD) gene is a transcription factor that plays a diverse role in plant development and in response to abiotic stresses. In this study, we isolated and developed CaMV35S::OsMLD rice lines and determined its expression pattern under abiotic stresses. It has Myb_CC_LHEQLE superfamily similar to most transcription factor genes but with a very unique binding domain of SHLQKYR in the C-terminal region. Overexpressing rice lines showed enhanced tolerance to salinity with elevated mRNA transcript. Additionally, mRNA transcripts were up-regulated by ABA, H2O2 and dehydration stresses. Further investigation in the enhanced tolerance to salinity showed an increased accumulation of proline and a decreased in malondialdehyde contents indicating that OsMLD gene may be involved in the regulation of proline and osmolytes during abiotic stresses. These results showed that OsMLD gene could be used in the development of rice intended for soil with salinity-related problem.

A cDNA clone encoding CBL-interacting protein kinase 1 (CIPK1) was isolated from Chinese cabbage seedlings. The gene, BrCIPK1 consisted of 1,982 bp long with 216 bp of the 5’-untranslated region (UTR), 1,509 bp of the coding region and 257 bp of the 3’-UTR. It is highly conserved CBL-interacting module with absolutely conserved domain among the 15 amino acid NAF domain of the 15 related genes. Southern blot analysis showed a single copy number. BrCIPK1 gene was localized in the cytoplasm and peripheral region in the plant cell which is highly expressed in seedling of rice and in the shoot and pistil of Arabidopsis. Analyses of gene expression on Ubi-1::BrCIPK1 rice lines was differentially accumulated by cold, salinity and drought, indicating its biological roles in the multiple stress response pathways in plants. Further, the expression of BrCIPK1 is hijacked by rice calcineurin-B-like protein (OsCBL5). Moreover, mRNA expression of P5CS1, a gene responsible for proline biosynthesis is regulated by the BrCIPK1 during abiotic stresses resulting to improved accumulation of proline. The interaction of BrCIPK1 with OsCBL5 along with the regulation of P5CS1 explained the enhanced tolerance of transgenic rice. This gene could be used in the development of rice varieties with enhanced tolerance to abiotic stresses.

MYB-like domain (MLD) gene is a transcription factor that plays a diverse role in plant development and in response to abiotic stresses. In this study, we isolated and developed CaMV35S::OsMLD rice lines and determined its expression pattern under abiotic stresses. The MLD has Myb_CC_LHEQLE superfamily similar to most transcription factor genes but with a very unique binding domain of SHLQKYR in the C-terminal region. Overexpressing rice lines showed enhanced tolerance to salinity with elevated mRNA transcript. Additionally, mRNA transcripts were up-regulated by ABA, H2O2 and dehydration stresses. Further investigation in the enhanced tolerance to salinity showed an increased accumulation of proline and a decreased in malondialdehyde contents indicating that OsMLD gene may be involved in the regulation of proline and osmolytes during abiotic stresses. These results showed that OsMLD gene could be used in the development of rice intended for soil with salinity-related problem.

The experimental determination of equilibrium constants is required to estimate concentrations of reagents and/or products in environmental chemical reactions. For an example, the choice of copper (Cu) complexation reactions was motivated by their fast kinetics and the ease of measurement of Cu by an ion‐sensitive electrode. Each individual titrant of sulfate (SO4 2‐) and oxalate (C2O4 2‐) was expected to have its own unique characteristics, depending on the bonding in Culigands connected to the aqueous species. The complexation reaction of Cu with SO4 2‐ somewhat fast reached equilibrium status compared with C2O4 2‐. The experimental equilibrium constants (Keq) of copper sulfate (CuSO4) and copper oxalate (CuC2O4) were determined 102.2 and 103~4.3, respectively.