• Water Engineering Research
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• v.3 no.4
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• pp.259-267
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• 2002

South Africa has developed a policy and law that calls and provides for the equitable and sustainable use of water resources. Sustainable resource use is dependent on effective resource protection. Rivers are the most important freshwater resources in the country, and there is a focus on developing and applying methods to quantify what rivers need in terms of flow and water quality. These quantified and descriptive objectives are then related to specified levels of ecological health in a classification system. This paper provides an overview of an integrated and systematic methodology, where, fer each river, and each river reach, the natural condition and the present ecological condition are described, and a level/class of ecosystem health is selected. The class will define long term management goals. This procedure requires each ecosystem component to be quantified, starting with the abiotic template. A modified flow regime is modelled for each ecosystem health class, and the resultant fluvial geomorphology and hydraulic habitats are described. Then the water chemistry is described, and the water quality changes that are likely to occur as a consequence of altered flows are predicted. Finally, the responses to the stress imposed on the biota (fish, invertebrates and vegetation) by modified flow and water quality are predicted. All of the predicted responses are translated into descriptive and/or quantitative management objectives. The paper concludes with the recognition of active method development, and the enormous challenge of applying the methods, implementing the law, and achieving river protection and sustainable resource-use.

• Plant Biotechnology Reports
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• v.3 no.2
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• pp.127-134
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• 2009

Members of the NAM-ATAF-CUC (NAC) protein family are plant-specific transcription factors that contain a highly conserved N-terminal NAC-domain and diverse C-terminal regions. They have been implicated in plant development and abiotic stress responses. To identify interacters of rice NAC-domain proteins (OsNACs), we performed yeast two-hybrid screening of rice cDNA library using OsNAC5 as a bait, and the results showed that OsNAC5 interacts with other OsNACs including itself. To delineate an interacting domain, a series of deletion constructs of four OsNACs were made and transformed into yeast in various combinations. The results revealed that the conserved NAC domain of OsNACs plays a primary role in homodimer and heterodimer formation, and a part of C-terminal sequence is also necessary for the interaction. In vitro pull-down assays using recombinant OsNAC proteins verified the dimer formations, together suggesting that OsNACs may act by forming homodimers and/or heterodimers in plants.

• Journal of Plant Biotechnology
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• v.37 no.1
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• pp.72-76
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• 2010

To develop transgenic cucumber tolerant to abiotic stress, a cotyledonary-node explants were co-cultivated with Agrobacterium tumefaciens (EHA101) carrying TPSP gene (pHC30-TPSP). After transfer to fresh medium every two week for eight weeks, putative transgenic plants were selected when shoots grown a length greater than 3 cm from the cotyledonary-node explants on selection medium supplemented with $5\;mgl^{-1}$ phospinotricin as selectable agent. The confirmation of transgenic cucumber was based on the Northern blot analysis. Thirty four shoots (5.2%) with resistance to phospinotricin were obtained from 660 explants inoculated. Of them, transformants were only confirmed from 11 plants (1.7%). Transgenic cucumber expressing TPSP gene was more synthesized at 3.8 times amounts of trehalose (0.014 mg g fresh $wt^{-1}$) than non-transformants (0.0037 mg g fresh $wt^{-1}$). However, all of transgenic plants showed abnormal morphology, including stunted growth (< height 15 cm), shrunken leaves, and sterility as compared with non-transgenic plants (> height 150 cm) under the same growth environment. These results lead us to speculate that the overproduction of trehalose was toxic for cucumber, even though that had known for rice as non-toxic.

• Journal of The Korean Society of Grassland and Forage Science
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• v.32 no.4
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• pp.325-334
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• 2012

It has been known that endophyte (Neotyphodium coenophialum) is beneficial to tall fescue (Schedonorus phoenix Scop.) because the mutualistic endophyte is able to confers tolerance against abiotic and biotic stresses to tall fescue. However, this fungal endophyte produces toxic alkaloid resulting in negative effects on animal performance. Recently, Non-toxic endophyte have been developed and inserted into tall fescue to avoid detrimental effect on animal but remaining positive influence on tall fescue. In order to keep this beneficial impact, it is essential to have endophyte infected tall fescue through vertical transmission from maternal plants to seeds. Little research has been carried out on endophyte transmission. To get basic information related to endophyte transmission, experiment was conducted to examine the effect of plant genotype on endophyte transmission under water stresses. Overall endophyte concentration in seeds was higher than that in panicles and endophyte concentration in seeds and panicles relied on plant. This study revealed that drought is not a critical component to control the endophyte transmission from maternal plants to seeds. Plant genotype is an important factor controlling the endophyte transmission from plant to seed.

• Molecules and Cells
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• v.22 no.1
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• pp.58-64
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• 2006

WRKY family proteins are a class of plant-specific transcription factors involved in stress response signaling pathways. In this study a gene encoding a putative WRKY protein was isolated from a pepper EST database (http://genepool.kribb.re.kr). The cDNA, named Capsicum annuum WRKY2 (CaWRKY2), encodes a putative polypeptide of 548 amino acids, containing two WRKY domains with zinc finger motifs and two potential nuclear localization signals. Northern blot analyses showed that CaWRKY2 mRNA was preferentially induced during incompatible interactions of pepper plants with PMMoV, Pseudomonas syringae pv. syringae 61, and Xanthomonas axonopodis pv. vesicatoria race 3. Furthermore, CaWRKY2 transcripts were strongly induced by wounding and ethephon treatment, whereas only moderate expression was detected following treatment with salicylic acid and jasmonic acid. CaWRKY2 was translocated to the nucleus when a CaWRKY2-smGFP fusion construct was expressed in onion epidermal cells. CaWRKY2 also had transcriptional activation activity in yeast. Taken together our data suggest that CaWRKY2 is a pathogen-inducible transcription factor that may have a role in early defense responses to biotic and abiotic stresses.

• BMB Reports
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• v.50 no.5
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• pp.235-236
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• 2017

The circadian clock is an internal system that is synchronized by external stimuli, such as light and temperature, and influences various physiological and developmental processes in living organisms. In the model plant Arabidopsis, transcriptional, translational and post-translational processes are interlocked by feedback loops among morning- and evening-phased genes. In a post-translational loop, plant-specific single-gene encoded GIGANTEA (GI) stabilize the F-box protein ZEITLUPE (ZTL), driving the targeted-proteasomal degradation of TIMING OF CAB EXPRESSION 1 (TOC1) and PSEUDO-RESPONSE REGULATOR 5 (PRR5). Inherent to this, we demonstrate the novel biochemical function of GI as a chaperone and/or co-chaperone of Heat-Shock Protein 90 (HSP90). GI prevents ZTL degradation as a chaperone and facilitates ZTL maturation together with HSP90/HSP70, enhancing ZTL activity in vitro and in planta. GI is known to be involved in a wide range of physiology and development as well as abiotic stress responses in plants, but it could also interact with diverse client proteins to increase protein maturation. Our results provide evidence that GI helps proteostasis of ZTL by acting as a chaperone and a co-chaperone of HSP90 for proper functioning of the Arabidopsis circadian clock.

• Mycobiology
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• v.48 no.2
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• pp.115-121
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• 2020

In this study, the genetic diversity and the population structure of 77 wild strains and 23 cultivars of Lentinula edodes from Korea were analyzed using 20 genomic SSRs, and their genetic relationship was investigated. The tested strains of L. edodes were divided into three sub-groups consisting of only wild strains, mainly wild strains and several cultivars, and mainly cultivars and several wild strains by distance-based analysis. Using model-based analysis, L. edodes strains were divided into two subpopulations; the first one consisting of only wild strains and the second one with mainly cultivars and several wild strains. Moreover, AMOVA analysis revealed that the genetic variation in the cultivars was higher than that in the wild strains. The expected and observed heterozygosity and values indicating the polymorphic information content of L. edodes cultivars from Korea were also higher than that of the wild strains. Based on these results, we presume that the cultivars in Korea have developed by using numerous strains from other countries. In conclusion, the usage of wild strains for the development of new cultivars could improve the adaptability of L. edodes to biotic and abiotic stress.

• Plant Resources
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• v.8 no.1
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• pp.1-8
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• 2005

A type 3 metallothionein cDNA (PMT3a) from ozone-treated Populus alba${\times}$Populus glandulosa cDNA library has been isolated and characterized. A PMT3a cDNA is 459 nucleotides long and has an open reading frame of 201 bp with a deduced amino acid sequence of 66 residues (pI 4.94). The deduced amino acid sequence of PMT3a matched to the previously reported metallothionein genes. The deduced amino acid sequence of PMT3a showed the $86\%$ identity with P. balsamifera ${\times}$P. deltoides. Expression of PMT3a by the RT-PCR was increased 60 min than 30 min after drought treatment. The ozone treated poplar increased at 30 min in the early time and then decreased at 60 min.

• Korean Journal of Medicinal Crop Science
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• v.16 no.4
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• pp.261-267
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• 2008

Malate dehydrogenase is a ubiquitous enzyme in plants, involving in a range of metabolic processes depending on its subcellular location. A malate dehydrogenase (PgMDH) cDNA was isolated and characterized from the root of Panax ginseng C. A. Meyer. The deduced amino acid sequence of PgMDH showed high similarity with the NAD-dependent mitochondrial malate dehydrogenase from Glycinemax (P17783), Eucalyptus gunnii (P46487), and Lycopersicon esculentum (AAU29198). And the segment of a malate dehydrogenase gene was amplified through RT-PCR. The expression of PgMDH was increased after treatments of chilling, salt, UV, cadmium or copper treatment.

• Journal of Radiation Industry
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• v.4 no.1
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• pp.47-51
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• 2010

Centipedegrass is a warm season turfgrass in the world. Chlorogenic acid (CA) is one of the important compounds present in the leaf of centipedegrass and already known as an antioxidant, CA has become a key resistance against insect pests and bacteria pathogens of agricultural and horticultural plants during seedling stage. Furthermore, CA is accumulated by abiotic stress such as an UV irradiation. In present study, we investigated enhancement of the level of CA upon gamma irradiation in centipedegrass. The high performance liquid chromatography (HPLC) data analysis showed an approximately increasing of the CA levels from among the irradiated samples. However, plants irradiated at 50 Gy showed a constant increase in the CA level (0.0066 to $0.114mg\;ml^{-1}$ and 0.0258 to $0.2211mg\;ml^{-1}$, respectively) from $3^{rd}$ to $15^{th}$ day among one and three month irradiated plants compared to control. The present study, indicates an increase in the CA level upon gamma irradiation, suggests strategy for conferment of strong resistance in seedling stage plants by gamma irradiation as simplicity and cheaply method.