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Bucheon, South Korea

Pok P.,Jeju National University | Oh E.U.,Jeju National University | Yi K.,Jeju National University | Kang J.H.,Jeju Special Self governing Province Agricultural Research & Extension Services | And 3 more authors.
Horticulture Environment and Biotechnology | Year: 2015

This study was conducted to investigate the seed formation potential by the evaluation of microspore development and self- and cross-compatibility through their pollen tube growth response to self and cross pollination in Jeju old local citrus species. Anther and pollen histological analyses were done to observe microspore development for three species including byungkyul, sadoogam, and dangyooza. Pollens of ten citrus species were tested for pollen viability by staining with Lugol’s solution and fluorescein diacetate. Flowers of all species were emasculated and self- and cross-pollinated just before anthesis. Pistils of nine pollinating combinations between the listed three species were collected at 1, 3, 5, 7, and 9 days after pollination for evaluation of a growth pattern of the pollen tube. Pistils of the other combinations were collected at 9 days after pollination for self- and cross-compatibility evaluation. Pistils were prepared by squashing and staining method with aniline blue. Eight pollen developmental stages were recognized and indicated normal development of microspore. These ten citrus species produced high percentage of viable pollens. Pollen tube behavior in compatible and incompatible pollination was distinguished. Pollen tube performance was largely depended on male-female combination. All of these Jeju old local citrus species were male fertile and have the ability to produce enough viable pollens for self- and cross-pollination. All evaluated citrus species were self- and cross-compatible to each other except dangyooza which was self-incompatible. © 2015, Korean Society for Horticultural Science and Springer-Verlag GmbH.

Nam K.-H.,Korea Research Institute of Bioscience and Biotechnology | Kim D.-Y.,Korea Research Institute of Bioscience and Biotechnology | Shin H.J.,Korea Research Institute of Bioscience and Biotechnology | Nam K.J.,Korea Research Institute of Bioscience and Biotechnology | And 6 more authors.
Food Chemistry | Year: 2014

Comparing well-watered versus deficit conditions, we evaluated the chemical composition of grains harvested from wild-type (WT) and drought-tolerant, transgenic rice (Oryza sativa L.). The latter had been developed by inserting AtCYP78A7, which encodes a cytochrome P450 protein. Two transgenic Lines, '10B-5' and '18A-4', and the 'Hwayoung' WT were grown under a rainout shelter. After the harvested grains were polished, their levels of key components, including proximates, amino acids, fatty acids, minerals and vitamins were analysed to determine the effect of watering system and genotype. Drought treatment significantly influenced the levels of some nutritional components in both transgenic and WT grains. In particular, the amounts of lignoceric acid and copper in the WT decreased by 12.6% and 39.5%, respectively, by drought stress, whereas those of copper and potassium in the transgenics rose by 88.1-113.3% and 10.4-11.9%, respectively, under water-deficit conditions. © 2013 Elsevier Ltd. All rights reserved.

Nam K.-H.,Korea Research Institute of Bioscience and Biotechnology | Nam K.J.,Korea Research Institute of Bioscience and Biotechnology | An J.H.,Korea Research Institute of Bioscience and Biotechnology | Jeong S.-C.,Korea Research Institute of Bioscience and Biotechnology | And 3 more authors.
Food Science and Biotechnology | Year: 2013

Nutritional composition is the main consideration in the safety assessment of foods derived from genetically modified (GM) crops. In this study, the key nutrients in drought-tolerant rice that had been generated by the insertion of AtCYP78A7 encoding cytochrome P450 protein were analyzed. Results were compared with those obtained from its non-transgenic counterpart and other commercial rice. When transgenic rice lines 10B-5 and 18A-4 were compared with the non-transgenic counterpart, no significant differences were found in their contents of proximates, amino acids, fatty acids, minerals, and vitamins. Except for fiber contents and levels of vitamin B2, most of the measured values fit within the reference ranges established for other commercial rice. These results indicate that the key nutritional composition of drought-tolerant transgenic rice is substantially equivalent to its non-transgenic counterpart. Therefore, insertion of AtCYP78A7 to improve drought tolerance does not change the constitution and quality of key nutrients in brown rice. © 2013 The Korean Society of Food Science and Technology and Springer Science+Business Media Dordrecht.

Nam K.-H.,Korea Research Institute of Bioscience and Biotechnology | Shin H.J.,Korea Research Institute of Bioscience and Biotechnology | Pack I.-S.,Korea Research Institute of Bioscience and Biotechnology | Park J.-H.,Korea Research Institute of Bioscience and Biotechnology | And 2 more authors.
Journal of the Science of Food and Agriculture | Year: 2016

BACKGROUND: Drought induces a number of physiological and biochemical responses in cereals. This study was designed to examine the metabolite changes in grains of drought-tolerant transgenic rice (Oryza sativa L.) that overexpresses AtCYP78A7 encoding cytochrome P450 protein using proton nuclear magnetic resonance (1H-NMR) and gas chromatography/mass spectrometry. RESULTS: Principal component analysis showed that the 1H-NMR-based profile was clearly separated by soil water status of well-watered and water-deficit. A discrimination of metabolites between transgenic and non-transgenic grains appeared under both watering regimes. Variations in the levels of amino acids and sugars led to the discrimination of metabolites among genotypes. In particular, drought significantly enhanced the levels of γ-aminobutyric acid (GABA, 244.6%), fructose (155.7%), glucose (211.0%), glycerol (57.2%), glycine (65.8%) and aminoethanol (192.4%) in the transgenic grains compared with the non-transgenic control grains. CONCLUSION: These changes in amounts of metabolites may assist in improving drought tolerance in transgenic rice by playing crucial roles in stress-responsive pathways including GABA biosynthesis, sucrose metabolism and antioxidant defenses. © 2016 Society of Chemical Industry.

Im J.H.,Seoul National University | Lee H.,Seoul National University | Lee H.,Korea Polar Research Institute KOPRI | Kim J.,Seoul National University | And 4 more authors.
Molecules and Cells | Year: 2012

Mitogen-activated protein kinase (MAPK) is activated by various biotic and abiotic stresses. Salt stress induces two well-characterized MAPK activating signaling molecules, phosphatidic acid (PA) via phospholipase D and phospholipase C, and reactive oxygen species (ROS) via nicotinamide adenine dinucleotide phosphate (NADPH)-oxidase. In our previous study, the activity of soybean MAPK, GMK1 was strongly induced within 5 min of 300 mM NaCl treatment and this early activity was regulated by PA. In this study, we focused on the regulation of GMK1 at the later stage of the salt stress, because its activity was strongly persistent for up to 30 min. H2O2 activated GMK1 even in the presence of PA generation inhibitors, but GMK1 activity was greatly decreased in the presence of diphenyleneiodonium, an inhibitor of NADPH-oxidase after 5 min of the treatment. On the contrary, the n-butanol and neomycin reduced GMK1 activity within 5 min of the treatment. Thus, GMK1 activity may be sustained by H2O2 10 min after the treatment. Further, GMK1 was translocated into the nucleus 60 min after NaCl treatment. In the relationship between GMK1 and ROS generation, ROS generation was reduced by SB202190, a MAPK inhibitor, but was increased in protoplast overexpressing TESD-GMKK1. However, these effects were occurred at prolonged time of NaCl treatment. These data suggest that GMK1 indirectly regulates ROS generation. Taken together, we propose that soybean GMK1 is dually regulated by PA and H2O2 at a time dependant manner and translocated to the nucleus by the salt stress signal. © The Korean Society for Molecular and Cellular Biology.

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