• Journal of Plant Biotechnology
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• v.36 no.2
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• pp.149-156
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• 2009

Application of exogenous polyamines (PAs) reduced the paraquat (PQ)-induced cotyledon injuries in radish seedling plants with 1 mM spermidine (Spd) being the most effective protectant. PQ injury symptoms in the cotyledons, e.g., large accumulation of $H_2O_2$, and losses of fresh weight, chlorophyll, and proteins, were significantly alleviated. Likewise, analysis of $H_2O_2$-scavenging enzymes such as catalase (CAT) and guaiacol peroxidase (GPX) showed that pretreatment with Spd among PAs remarkably increased total CAT activity and strongly retarded PQ-induced rapid decline in total GPX activity. In a native gel assay, one CAT isozyme (CAT1) and two GPX isozymes (GPX1 and a newly synthesized GPX isozyme) proved to be more responsible for PQ tolerance, as manifested by the strong increases in their activities by Spd pretreatment. Based on these results, we can suggest that PAs (especially 1 mM Spd) may function as antioxidant protectors by invoking CAT and GPX enzymes which control the endogenous $H_2O_2$ level in radish cotyledons exposed to PQ.

• Journal of Mushroom
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• v.17 no.3
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• pp.85-92
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• 2019

Over a million tons of spent mushroom substrate (SMS) are generated as by-products of mushroom cultivation every year in Korea. Disposal of SMS by mushroom farmers is difficult, therefore, recycling solutions that do not harm the environment are necessary. SMS consists of mushroom mycelia and residues of fruiting bodies, containing a variety of bioactive substances, such as extracellular enzymes, antimicrobial compounds, and secondary metabolites. This paper reviews utility of SMS for bioremediation, controlling plant disease, and production of lignocellulytic enzymes, organic fertilizer, and animal feed.

• Journal of Marine Bioscience and Biotechnology
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• v.12 no.1
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• pp.50-58
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• 2020

Sphacelaria is a filamentous brown algal genus that can be epibiotic on macroalgae, marine plants, and sea turtles. Its important role in benthic ecosystems, exposure to different stressors (e.g., grazing), and use as a model organism make Sphacelaria ideal for assessing physiological responses of organisms to environmental inputs. Single-cell RNA sequencing is a powerful new probe for understanding environmental responses of organisms at the molecular (transcriptome) level, capable of delineating gene regulation in different cell types. In the case of plants, this technique requires protoplasts ("naked" plant cells). The existing protoplast isolation protocols for Sphacelaria use non-commercial enzymes and are low-yielding. This study is the first to report the production of protoplasts from Sphacelaria fusca (Hudson) S.F. Gray, using a combination of commercial enzymes, chelation, and osmolarity treatment. A simple combination of commercial enzymes (cellulase Onozuka RS, alginate lyase, and driselase) with chelation pretreatment and an increased osmolarity (2512 mOsm/L H₂O) gave a protoplast yield of 15.08 ± 5.31 × 10⁴ protoplasts/g fresh weight, with all the Sphacelaria cell types represented. Driselase had no crucial effect on the protoplast isolation. However, the increased osmolarity had a highly significant and positive effect on the protoplast isolation, and chelation pretreatment was essential for optimal protoplast yield. The protocol represents a significant step forward for studies on Sphacelaria by efficiently generating protoplasts suitable for cellular studies, including single-cell RNA sequencing and expression profiling.

• BMB Reports
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• v.43 no.11
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• pp.726-731
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• 2010

We report the tissue-specific distribution of chitinolytic activity in Korean ginseng root and characterize two 31-kDa chitinolytic enzymes. These two enzymes (SBF1 and SBF2) were purified 70- and 81-fold with yields of 0.75 and 1.25%, respectively, and exhibited optimal pH and temperature ranges of 5.0-5.5 and 40-$50^{\circ}C$. With [$^3H$]-chitin as a substrate, $K_m$ and $V_{max}$ values of SBF1 were 4.6 mM and 220 mmol/mg-protein/h, respectively, while those of SBF2 were 7.14 mM and 287 mmol/mg-protein/h. The purified enzymes showed markedly less activity with p-nitrophenyl-N-acetylglucosaminide and fluorescent 4-methylumbelliferyl glycosides of D-N-acetylglucosamine oligomers than with [$^3H$]-chitin. End-product inhibition of both enzymes demonstrated that both are endochitinases with different N-acetylglucosaminidase activity. Furthermore, the $NH_2$-terminal sequence of SBF1 showed a high degree of homology with other plant chitinases whereas the $NH_2$-terminal amino acid of SBF2 was blocked.

• Proceedings of the Plant Resources Society of Korea Conference
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• 2003.10b
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• pp.17-17
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• 2003

Enzymes involved in catecholamine synthesis are present in the highest concentration in the adrenal medulla, however they were found also in other, mainly nervous tissues. Increased transcription of genes for catecholamine biosynthetic enzymes is an important mechanism to increase the capacity for epineprine/norepinephrine biosynthesis with stress. Gastrodia elata(Chinese name: Tienma), are very important Chinese herbal medicines used for the medical treatment of headaches, migraine, dizziness, epilepsy, rheumatism, neuralgia, paralysis and other neuralgic and nervous disorders. Immobilize stressed rat markedly increased tyrosine hydroxylase (TH) mRNA and dopamine-${\beta}$-hydroxylase (DBH) mRNA transcriptior level more than control group. But treated Gastrodia elata extracts in immobilized stressed rat slightly increased TH mRNA and DBH mRNA transcription level more than normal group. In addition, we are obtained identical results in PC12 cell line. Decrease of transcription level of TH mRNA and DBH mRNA is indicating that Gastrodia elata have a anti-stress effects which decrease the transcription level of TH and DBH mRNA on catecholamine biosynthesis pathway.

• Journal of Plant Biology
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• v.37 no.3
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• pp.357-363
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• 1994

An expreiment with non-nodulating alfalfa (Medicago sativa L.) plants was designed to investigate the changes in protein contents and the activities of proteolytic enzymes during a regrowth period of 24 d. Shoot removal caused a depression of root growth and significantly reduced protein contents in roots. An initial decline of root proteins for the first 10 d was followed by a rapid recovery from d 11 to 24. The major increase of regrowing shoot weight occurred also from d 11. The activities of aminopeptidase and endoprotease slightly decreased in regrowing leaves, while protein contents remains stable after shoot removal. Roots exhibited source behaviour with a rapid increase of endoprotease activities for the first 10 d of regrowth; about a 370% increase over the initial level was observed. Increase in endoprotease activity in roots coincided with the time of protein remobilization after shoot removal, indicating the important role of endoproteases in protein degradation.

• Journal of Plant Biology
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• v.29 no.4
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• pp.243-254
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• 1986

The enzyme patterns and the food storage changes in radish (Raphanus sativus L. cv. Taewang) cotyledons during seedling development were studied. The radish seeds were germinated for 8 days at $25^{\circ}C$ under light (7, 000 lux) or dark condition. The lipid and protein contents per seed were 4.3 mg and 2.85 mg respectively. In 8-day-old light-grown seedling, the lipid and protein contents per cotyledon pair were 1.5 mg and 2.08 mg; in 8-day-old dark-grown seedling, they were 0.8 mg and 1.24 mg respectively. The heterotrophic phase of seedlings continued for 3 days after sowing and followed by autotrophic phase (3~6 day) and senescence phase (6~8 day). The food storage function decreased in response to time course. During heterotrophic phase, the activities of glyoxysomal enzymes (malate synthetase, isocitrate lyase, and catalase) were high at 2~3 day. Those patterns were somewhat more prominent in darkness. During the autotrophic phase, the activities of peroxysomal enzymes (glycolate oxidase and catalase) increased at 4~5 day.

• Journal of Plant Biology
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• v.16 no.1_2
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• pp.6-11
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• 1973

The utilization of acetate by Dunaliella tertiolecta was examined, and the detections and assays of the enzymes of the tricarboxylic acid cycle and the glyoxylate pathway were described. Acetate could not be utilized as a sole carbon source for the growth. The carboxyl carbon of acetate was incorporated more rapidly into CO2 than the methyl carbon. It was identified that malate, succinate, citrate and etc., were accumulated whne [U-14C] acetate was supplied to the cell free homogenate. The following enzyme activities were measured; acetothiokinase, isocitrate dehydrogenase, fumarase, malate dehydrogenase and aconitase. Though isocitratase, malate synthetase, succinate dehydrogenase and oxoglutarate dehydrogenase could not be detected, 14C from succinate was easily contributed to CO2 and cell component. The evidence suggested that the glyoxylate pathway was not operative and showed that the TCA cycle was the all important pathway in the oxidation of acetate to CO2 in Dunaliella.

• Journal of Plant Biology
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• v.29 no.2
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• pp.85-94
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• 1986

Canavanine content of the cotyledons of Canavalia lineata decreased gradually during germination and growth of seedlings but continued to increase in roots and leaves. After abscission of cotyledons, canavanine content of leaves depleted competely. The activity of canavanase could be detected in leaves and roots, but not in cotyledons. High arginase activity was observed in the cotyledons of seeds at the earlyimbibition period. During the growth of seedlings, cotyledonary canavanine appeared to be transported to the growing of seedlings where it could be utilized through nitrogen metabolic pathways. In crude cell-free extracts of leaves, maximum activities of canavanase or arginase appeared in 30mM Tris-HCl buffer (pH 9.0) or 30mM NaHCO3 buffer (pH 10.0), respectively. The activities of these two enzymes differed from each other when treated with Co2+ or Mn2+. These results support the idea that canavanase and arginase might be different enzymes.

• Korean Journal Plant Pathology
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• v.14 no.2
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• pp.157-163
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• 1998

Genetic diversity among 27 isolates of Rhizoctonia solani, which were obtained from diseased crops in Korea and classified into 9 intraspecific groups by anastomosis test and cultural characteristics, was studied by PCR-RFLP. Gene regions of nuclear 17S ribosomal DNA and internal transcribed spacers including 5.8S rDNA of the isolates were amplified with polymerase chain reaction and digested with 12 restriction enzymes. Differences of restriction patterns were not shown among isolates within each intraspecific groups, however, each anastomosis group and culturala type sowed unique restriction fragment length polymorphisms by restriction patterns using HaeIII, Cfr13I and MspI. The results suggest that PCR-FRLP of rDNA using three restriction enzymes could be used to differentiate intraspecific groups of Rhizoctonia solani in Korea.