• 원예과학기술지
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• 제35권2호
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• pp.243-251
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• 2017

Plants have evolved to adapt to abiotic stresses, such as salt, cold, and drought stress. In this study, we conducted an in-depth analysis of drought resistance mechanisms by constructing a gene co-expression network in Chinese cabbage (Brassica rapa ssp. pekinensis L.). This drought stress co-expression network has 1,560 nodes, 4,731 edges, and 79 connected components. Based on genes that showed significant co-expression in the network, drought tolerance was associated with the induction of reactive oxygen species removal by raffinose family oligosaccharides and inositol metabolism. This network could be a useful tool for predicting the functions of genes involved in drought stress resistance in Chinese cabbage.

• Molecules and Cells
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• 제39권3호
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• pp.179-185
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• 2016

Posttranscriptional regulation of RNA metabolism, including RNA processing, intron splicing, editing, RNA export, and decay, is increasingly regarded as an essential step for fine-tuning the regulation of gene expression in eukaryotes. RNA-binding proteins (RBPs) are central regulatory factors controlling posttranscriptional RNA metabolism during plant growth, development, and stress responses. Although functional roles of diverse RBPs in living organisms have been determined during the last decades, our understanding of the functional roles of RBPs in plants is lagging far behind our understanding of those in other organisms, including animals, bacteria, and viruses. However, recent functional analysis of multiple RBP family members involved in plant RNA metabolism and elucidation of the mechanistic roles of RBPs shed light on the cellular roles of diverse RBPs in growth, development, and stress responses of plants. In this review, we will discuss recent studies demonstrating the emerging roles of multiple RBP family members that play essential roles in RNA metabolism during plant growth, development, and stress responses.

• Journal of Plant Biotechnology
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• 제44권3호
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• pp.220-228
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• 2017

식용작물, 사료, 잔디를 포함하는 모든 작물은 건조, 염, 저온, 고온 등의 여러 가지 환경스트레스의 영향을 빈번히 받기 때문에 작물의 생산성이 떨어지게 된다. 식물은 환경스트레스 상황에서 스스로 벗어날 수 없다. 따라서 식물은 환경 스트레스를 극복하는 방향으로 진화하였다. ARF, ABI3, NAC, HSF, WRKY 같은 환경 스트레스에 반응하는 유전자들이 식물에서 보고되었다. 이 유전자들은 환경스트레스에 반응하는 전사인자로, 식물의 스트레스반응 경로에 연관되어 있다. OsWRKY76의 경우에는 저온 및 병원균에 대한 내성을 증가시켰고, AtWRKY28 의 경우 여러 가지 환경스트레스에 관련이 있는 것으로 보고되었다. 들잔디는 정원이나 골프코스에서 가장 흔하게 사용되는 잔디이다. 하지만 들잔디에서는 아직 WRKY 유전자가 알려지지 않았다. 본 연구에서는 들잔디로부터 1개의 WRKY domain을 포함하는 ZjWRKY3, ZjWRKY7 를 분리하였다. ZjWRKY3과 ZjWRKY7은 저온, 건조, 염 스트레스에 발현이 증가하였다. 들잔디의 갈색퍼짐병을 일으키는 R. solani의 감염이 ZjWRKY3과 ZjWRKY7의 발현을 증가시켰다. 또한 ZjWRKY3, ZjWRKY7이 Zjchi 유전자 promoter의 W-box에 결합하여 전사를 조절한다는 사실을 확인 하였다. 따라서 ZjWRKY3, ZjWRKY7 유전자는 전사인자로서 환경스트레스 및 병원균 관련 하위 유전자들을 조절할 것으로 예상된다.

• 생명과학회지
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• 제27권12호
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• pp.1415-1420
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• 2017

고구마 현탁배양세포의 EST library에 높은 빈도로 존재하는 metallothionein (MT) 유전자를 선별하였다(IbMT3). MT 유전자는 세포와 조직의 스트레스 조절과 연관되어 있다고 알려져 있다. 본 연구에서 IbMT3 cDNA의 전장을 확보하여 염기서열 분석을 한 결과, IbMT3 유전자는 구조적으로 유형 3에 속하는 MT 단백질을 암호화하고 있었다. 식물에서 유형 3에 속하는 MT 단백질의 기능은 명확히 알려지지 않다. Northern blot 분석 결과, IbMT3 유전자는 고구마 식물체 잎보다 현탁배양 세포에서 매우 강하게 발현되었다. 일반적으로 세포배양은 세포에 산화 스트레스 상태를 부과하는 것으로 알려져 있다. 이에, 고구마 식물체에 산화 스트레스를 처리하여 IbMT3 유전자의 발현이 어떻게 조절되는지 조사하였다. 제초제인 methyl viologen (MV)을 6, 12, 24시간 동안 처리했을 때, IbMT3 유전자의 발현은 6시간 후에 아주 강하게 유도되었고 그 이후에는 감소함을 알 수 있었다. 저온 스트레스($15^{\circ}C$)를 24, 48시간 동안 처리했을 때, IbMT3 유전자는 처리시간이 경과함에 따라 발현이 더 많이 유도되었다. 이로써, IbMT3 유전자는 환경 및 산화 스트레스에 반응하여 발현이 조절되는 유전자임을 알 수 있었다. IbMT3 isoform은 고구마 식물체 내에서 항산화제로써 작용할 가능성이 있을 뿐 아니라, 스트레스 하에서의 세포 적응 메커니즘에 중요한 기능을 할 것으로 사료된다.

• Genes and Genomics
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• 제40권11호
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• pp.1181-1197
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• 2018

Tropical plant rubber tree (Hevea brasiliensis) is the sole source of commercial natural rubber and low-temperature stress is the most important limiting factor for its cultivation. To characterize the gene expression profiles of H. brasiliensis under the cold stress and discover the key cold stress-induced genes. Three cDNA libraries, CT (control), LT2 (cold treatment at $4^{\circ}C$ for 2 h) and LT24 (cold treatment at $4^{\circ}C$ for 24 h) were constructed for RNA sequencing (RNA-Seq) and gene expression profiling. Quantitative real time PCR (qRT-PCR) was conducted to validate the RNA-Seq and gene differentially expression results. A total of 1457 and 2328 differentially expressed genes (DEGs) in LT2 and LT24 compared with CT were respectively detected. Most significantly enriched KEGG pathways included flavonoid biosynthesis, phenylpropanoid biosynthesis, plant hormone signal transduction, cutin, suberine and wax biosynthesis, Pentose and glucuronate interconversions, phenylalanine metabolism and starch and sucrose metabolism. A total of 239 transcription factors (TFs) were differentially expressed following 2 h or/and 24 h of cold treatment. Cold-response transcription factor families included ARR-B, B3, BES1, bHLH, C2H, CO-like, Dof, ERF, FAR1, G2-like, GRAS, GRF, HD-ZIP, HSF, LBD, MIKC-MADS, M-type MADS, MYB, MYB-related, NAC, RAV, SRS, TALE, TCP, Trihelix, WOX, WRKY, YABBY and ZF-HD. The genome-wide transcriptional response of rubber tree to the cold treatments were determined and a large number of DEGs were characterized including 239 transcription factors, providing important clues for further elucidation of the mechanisms of cold stress responses in rubber tree.

• 한국초지조사료학회지
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• 제33권3호
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• pp.159-166
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• 2013

We have previously investigated the proteome changes of rice leaves under heat stress (Lee et al. in Proteomics 2007a, 7:3369-3383), wherein a group of antioxidant proteins and heat shock proteins (HSPs) were found to be regulated differently. The present study focuses on the biochemical changes and gene expression profiles of heat shock protein and antioxidant genes in rice leaves in response to heat stress ($42^{\circ}C$) during a wide range of exposure times. The results show that hydrogen peroxide and proline contents increased significantly, suggesting an oxidative burst and osmotic imbalance under heat stress. The mRNA levels of chaperone 60, HSP70, HSP100, chloroplastic HSP26, and mitochondrial small HSP responded rapidly and showed maximum expression after 0.5 or 2 h under heat stress. Transcript levels of ascorbate peroxidase (APX), dehydroascorbate reductase (DHAR) and Cu-Zn superoxide dismutase (Cu-Zn SOD) showed a rapid and marked accumulation upon heat stress. While prolonged exposure to heat stress resulted in increased transcript levels of monodehydroascorbate reductase, peroxidase, glyoxalase 1, glutathione reductase, thioredoxin peroxidase, 2-Cysteine peroxiredoxin, and nucleoside diphosphate kinase 1, while the transcription of catalase was suppressed. Consistent with their changes in gene expression, the enzyme activities of APX and DHAR also increased significantly following exposure to heat stress. These results suggest that oxidative stress is usually caused by heat stress, and plants apply complex HSP- and antioxidant-mediated defense mechanisms to cope with heat stress.

• The Korean Journal of Physiology and Pharmacology
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• 제18권5호
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• pp.403-409
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• 2014

The Bis protein is known to be involved in a variety of cellular processes including apoptosis, migration, autophagy as well as protein quality control. Bis expression is induced in response to a number of types of stress, such as heat shock or a proteasome inhibitor via the activation of heat shock factor (HSF)1. We report herein that Bis expression is increased at the transcriptional level in HK-2 kidney tubular cells and A172 glioma cells by exposure to oxidative stress such as $H_2O_2$ treatment and oxygen-glucose deprivation, respectively. The pretreatment of HK-2 cells with N-acetyl cysteine, suppressed Bis induction. Furthermore, HSF1 silencing attenuated Bis expression that was induced by $H_2O_2$, accompanied by increase in reactive oxygen species (ROS) accumulation. Using a series of deletion constructs of the bis gene promoter, two putative heat shock elements located in the proximal region of the bis gene promoter were found to be essential for the constitutive expression is as well as the inducible expression of Bis. Taken together, our results indicate that oxidative stress induces Bis expression at the transcriptional levels via activation of HSF1, which might confer an expansion of antioxidant capacity against pro-oxidant milieu. However, the possible role of the other cis-element in the induction of Bis remains to be determined.

• BMB Reports
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• 제36권1호
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• pp.95-109
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• 2003

Inflammatory lung diseases are characterized by chronic inflammation and oxidant/antioxidant imbalance. The sources of the increased oxidative stress in patients with chronic inflammatory lung diseases such as asthma and chronic obstructive pulmonary disease (COPD) derive from the increased burden of inhaled oxidants, and from the increased amounts of reactive oxygen species (ROS) generated by several inflammatory, immune and various structural cells of the airways. Increased levels of ROS produced in the airways is reflected by increased markers of oxidative stress in the airspaces, sputum, breath, lungs and blood in patients with lung diseases. ROS, either directly or via the formation of lipid peroxidation products such as 4-hydroxy-2-nonenal may play a role in enhancing the inflammation through the activation of stress kinases (JNK, MAPK, p38) and redox sensitive transcription factors such as NF-${\kappa}B$ and AP-1. Recent evidences have indicated that oxidative stress and pro-inflammatory mediators can alter nuclear histone acetylation/deacetylation allowing access for transcription factor DNA binding leading to enhanced pro-inflammatory gene expression in various lung cells. Understanding of the mechanisms of redox signaling, NF-${\kappa}B$/AP-1 regulation, the balance between histone acetylation and deacetylation and the release and expression of pro- and anti-inflammatory mediators may lead to the development of novel therapies based on the pharmacological manipulation of antioxidants in lung inflammation and injury. Antioxidants that have effective wide spectrum activity and good bioavailability, thiols or molecules which have dual antioxidant and anti-inflammatory activity, may be potential therapeutic agents which not only protect against the direct injurious effects of oxidants, but may fundamentally alter the underlying inflammatory processes which play an important role in the pathogenesis of chronic inflammatory lung diseases.

• 미생물학회지
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• 제47권2호
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• pp.124-129
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• 2011

Helicobacter pylori균의 ferric uptake regulator (Fur) 단백질의 산화적 손상에 대한 역할을 연구하였다. H. pylori균의 fur 유전자를 제거한 돌연변이체를 만들고 wild type H. pylori균과 돌연변이체 균의 산화적 스트레스에 대한 반응을 비교하였다. 산화적 스트레스는 methylene blue와 660 nm 파장의 빛을 이용하는 광역학적 치료방법으로 유도하였다. 산화적 스트레스를 가한 실험조건에서 wt H. pylori와 돌연변이체의 생존력, DNA 손상의 정도를 비교 검토하였다. 그 결과 fur 유전자가 제거된 돌연변이체의 생균수가 wt에 비해 10,000배 가량 감소한 것을 알 수 있었으며 DNA의 산화적 손상의 marker인 8-hydroxy-2-deoxyguanosine (8-OHdG)의 양도 fur 유전자 제거된 돌연변이에서 wild type에 비해 3배 정도 더 생성됨을 확인하였다. 따라서 본 실험결과 H. pylori균의 fur 유전자가 PDT법으로 유도한 산화적 스트레스에 방어 기작을 하는 것으로 사료된다.

• Asian-Australasian Journal of Animal Sciences
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• 제25권1호
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• pp.92-97
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• 2012

The trial was conducted to evaluate the effects of sea buckthorn leaves (SBL) on meat flavor in broilers during heat stress. A total 360 one-day-old Arbor Acre (AA) broilers (male) were randomly allotted to 4 treatments with 6 replicates pens pretreatment and 15 birds per pen. The control group was fed a basal diet, the experimental group I, II and III were fed the basal diet supplemented with 0.25%, 0.5%, 1% SBL, respectively. During the 4th week, broilers were exposed to heat stress conditions ($36{\pm}2^{\circ}C$), after which, muscle and liver samples were collected. High performance liquid chromatography (HPLC) was performed to measure the content of inosine monophosphate (IMP); Real-Time PCR was performed to determine the expression of the ADSL gene. The results showed that the content of breast muscle IMP of group I, II and III was significantly increased 68%, 102% and 103% (p<0.01) compared with the control, respectively; the content of thigh muscle IMP of group II and III was significantly increased 56% and 58% (p<0.01), respectively. Additionally, ADSL mRNA expression in group I, II and III was increased significantly 80%, 65% and 49% (p<0.01) compared with the control, respectively. The content of IMP and expression of ADSL mRNA were increased by basal diet supplemented with SBL, therefore, the decrease of meat flavor caused by heat stress was relieved.