• Plant Biotechnology Reports
• /
• 제3권3호
• /
• pp.183-190
• /
• 2009

Rho-related GTPase of plants (ROP) plays an important role in plant growth and development as a signaling protein. Plant RopGEFs are recently identified ROP activator proteins in Arabidopsis. In this study, we cloned 14 RopGEFs in Arabidopsis and characterized their expression patterns in response to abiotic stresses. Fourteen RopGEF genes were categorized into three groups based on their amino acid homologies and molecular sizes. Most RopGEFs were expressed predominantly in flower but some RopGEFs displayed a tissue-specific expression pattern. RopGEF1, 4, 5, and 11 were expressed in all tissues including root and leaves whereas RopGEF7, 8, 9, and 13 were expressed only in flowers. The transcript levels of 14 RopGEFs were changed significantly depending upon abiotic stresses such as cold, heat, drought and salts. RopGEF5 transcription was up-regulated by salt and drought treatment but down-regulated by heat. RopGEF14 transcript level was also increased by salt but decreased by heat stress. The transcript levels of RopGEF1, 7, 9, and 12 were enhanced in response to heat stress but showed no changes in response to cold stresses. Drought stress activated Group 3 RopGEFs such as RopGEF5 and 7. Taken together, 14 RopGEFs are responding to the abiotic stresses individually or as a group.

• Journal of Plant Biotechnology
• /
• 제41권1호
• /
• pp.26-32
• /
• 2014

Recent genome annotation revealed that Populus trichocarpa contains 81 glutathione S-transferase (GST) genes. GST genes play important and varying roles in plants, including conferring tolerance to various abiotic stresses. Little information is available on the relationship - if any - between drought/salt stresses and GSTs in woody plants. In this study, we screened the PatgGST genes in hybrid poplar (Populus alba ${\times}$ Populus tremula var. glandulosa) that were predicted to confer drought tolerance based on our expression analysis of all members of the poplar GST superfamily following exposure to salt (NaCl) and drought (PEG) stresses, respectively. Exposure to the salt stress resulted in the induction of eight PatgGST genes and down-regulation of one PatgGST gene, and the level of induction/repression was different in leaf and stem tissues. In contrast, 16 PatgGST genes were induced following exposure to the drought (PEG) stress, and two were down-regulated. Taken together, we identified seven PatgGSTs (PatgGSTU15, PatgGSTU18, PatgGSTU22, PatgGSTU27, PatgGSTU46, PatgGSTU51 and PatgGSTU52) as putative drought tolerance genes based on their induction by both salt and drought stresses.

• Molecules and Cells
• /
• 제28권5호
• /
• pp.479-487
• /
• 2009

Glutathione reductase (GR) is an enzyme that recycles a key cellular antioxidant molecule glutathione (GSH) from its oxidized form (GSSG) thus maintaining cellular redox homeostasis. A recombinant plasmid to overexpress a GR of Brassica rapa subsp. pekinensis (BrGR) in E. coli BL21 (DE3) was constructed using an expression vector pKM260. Expression of the introduced gene was confirmed by semi-quantitative RT-PCR, immunoblotting and enzyme assays. Purification of the BrGR protein was performed by IMAC method and indicated that the BrGR was a dimmer. The BrGR required NADPH as a cofactor and specific activity was approximately 458 U. The BrGR-expressing E. coli cells showed increased GR activity and tolerance to $H_2O_2$, menadione, and heavy metal ($CdCl_2$, $ZnCl_2$ and $AlCl_2$)-mediated growth inhibition. The ectopic expression of BrGR provoked the co-regulation of a variety of antioxidant enzymes including catalase, superoxide dismutase, glutathione peroxidase, and glucose-6-phosphate dehydrogenase. Consequently, the transformed cells showed decreased hydroperoxide levels when exposed to stressful conditions. A proteomic analysis demonstrated the higher level of induction of proteins involved in glycolysis, detoxification/oxidative stress response, protein folding, transport/binding proteins, cell envelope/porins, and protein translation and modification when exposed to $H_2O_2$ stress. Taken together, these results indicate that the plant GR protein is functional in a cooperative way in the E. coli system to protect cells against oxidative stress.

• Biomolecules & Therapeutics
• /
• 제29권3호
• /
• pp.311-320
• /
• 2021

Accumulation of reactive oxygen species (ROS) is associated with the development of various diseases. However, the molecular mechanisms underlying oxidative stress that lead to such diseases like autosomal dominant polycystic kidney disease (ADPKD) remain unclear. Here, we observed that oxidative stress markers were increased in Pkd1f/f:HoxB7-Cre mice. Forkhead transcription factors of the O class (FOXOs) are known key regulators of the oxidative stress response, which have been observed with the expression of FoxO3a in an ADPKD mouse model in the present study. An integrated analysis of two datasets for differentially expressed miRNA, such as miRNA sequencing analysis of Pkd1 conditional knockout mice and microarray analysis of samples from ADPKD patients, showed that miR-132-3p was a key regulator of FOXO3a in ADPKD. miR-132-3p was significantly upregulated in ADPKD which directly targeted FOXO3 in both mouse and human cell lines. Interestingly, the mitochondrial gene Gatm was downregulated in ADPKD which led to a decreased inhibition of Foxo3. Overexpression of miR-132-3p coupled with knockdown of Foxo3 and Gatm increased ROS and accelerated cyst formation in 3D culture. This study reveals a novel mechanism involving miR-132-3p, Foxo3, and Gatm that is associated with the oxidative stress that occurs during cystogenesis in ADPKD.

• Journal of Microbiology and Biotechnology
• /
• 제32권9호
• /
• pp.1110-1119
• /
• 2022

Fe-S clusters are versatile and essential cofactors that participate in multiple and fundamental biological processes. In Escherichia coli, the biogenesis of these cofactors requires either the housekeeping Isc pathway, or the stress-induced Suf pathway which plays a general role under conditions of oxidative stress or iron limitation. In the present work, the Fe-S cluster assembly Isc and Suf systems of acidophilic Bacteria and Archaea, which thrive in highly oxidative environments, were studied. This analysis revealed that acidophilic microorganisms have a complete set of genes encoding for a single system (either Suf or Isc). In acidophilic Proteobacteria and Nitrospirae, a complete set of isc genes (iscRSUAX-hscBA-fdx), but not genes coding for the Suf system, was detected. The activity of the Isc system was studied in Leptospirillum sp. CF-1 (Nitrospirae). RT-PCR experiments showed that eight candidate genes were co-transcribed and conform the isc operon in this strain. Additionally, RT-qPCR assays showed that the expression of the iscS gene was significantly up-regulated in cells exposed to oxidative stress imposed by 260 mM Fe₂(SO₄)₃ for 1 h or iron starvation for 3 h. The activity of cysteine desulfurase (IscS) in CF-1 cell extracts was also upregulated under such conditions. Thus, the Isc system from Leptospirillum sp. CF-1 seems to play an active role in stressful environments. These results contribute to a better understanding of the distribution and role of Fe-S cluster protein biogenesis systems in organisms that thrive in extreme environmental conditions.

• 한국작물학회:학술대회논문집
• /
• 한국작물학회 2022년도 추계학술대회
• /
• pp.229-229
• /
• 2022

Rapeseed is a crop that is waterlogging sensitive, and it is necessary to breed waterlogging tolerance varieties. Our study presents the comparative transcriptome changes in two rapeseed lines, i.e., waterlogging-tolerant (tJ8634-B-30,) and - sensitive ('EMS26') lines under control and waterlogging stress treatments at the flowering stage. RNA-sequencing analysis revealed 13,279 differentially expressed genes (DEGs) for 'J8634-B-30' and 8,682 DEGs for 'EMS26' under waterlogging stress condition compared to control. Among DEGs of 'J8634-B-30', 6,818 were up-regulated and 6,461 were down-regulated. On the other hand, among the DEGs of 'EMS26', the number of down-regulated genes (5,240) were higher than that of up-regulated genes (3,442). Gene ontology enrichment analysis showed that DEGs related to glucan metabolic, cell wall, and oxidoreductase activity were significantly changed in 'J8634-B-30'. Kyoto Encyclopedia of Genes and Genomes (KEGG)-based analysis in 'J8634-B-30' identified up-regulated DEGs being involved in MAPK signaling pathways. In addition, the DEGs belonging to mechanisms responding to waterlogging stress, i.e., plant hormones, carbon metabolism, Reactive oxygen species (ROS), Nitric oxide (NO) etc. were compared in rapeseed lines. Several DEGs including ethylene-responsive transcription factor (ERF), constitutive triple response (CTR) (in ethylene signaling pathway), monodehydroascorbate Reductase (MDAR), NADPH oxidase (in ROS pathway), cytochrome c oxidase assembly protein (COX) (in NO pathway) up-regulated in 'J8634-B-30'. These outcomes provided the valuable information for further exploring the genetic mechanism of waterlogging tolerance in rapeseed.

• Clinical and Experimental Reproductive Medicine
• /
• 제51권1호
• /
• pp.28-41
• /
• 2024

Objective: Chronic scrotal hyperthermia (SHT) can lead to serious disorders of the male reproductive system, with oxidative stress playing a key role in the onset of these dysfunctions. Thus, we evaluated the impact of caffeine, a potent antioxidant, on cellular and tissue disorders in mice with chronic SHT. Methods: In this experimental study, 56 adult male NMRI mice were allocated into seven equal groups. Apart from the non-treated control group, all were exposed to heat stress. Two groups, termed "preventive" and "curative," were orally administered caffeine. The preventive mice began receiving caffeine immediately prior to heat exposure, while for the curative group, a caffeine regimen was initiated 15 consecutive days following cessation of heat exposure. Each treated group was subdivided based on pairing with a positive control (Pre/ curative [Cur]+PC) or a vehicle (Pre/Cur+vehicle). Upon conclusion of the study, we assessed sperm characteristics, testosterone levels, stereological parameters, apoptosis, antioxidant and oxidant levels, and molecular markers. Results: Sperm parameters, testosterone levels, stereological parameters, biochemical factors (excluding malondialdehyde [MDA]), and c-kit gene expression were significantly elevated in the preventive and curative groups, especially the former, relative to the other groups. Conversely, expression levels of the heat shock protein 72 (HSP72) and nuclear factor kappa beta (NF-κβ) genes, MDA levels, and apoptotic cell density were markedly lower in both caffeine-treated groups relative to the other groups, with more pronounced differences observed in the preventive group. Conclusion: Overall, caffeine attenuated cellular and molecular abnormalities induced by heat stress in the testis, particularly in the mice treated under the preventive condition.

• 원예과학기술지
• /
• 제33권1호
• /
• pp.114-123
• /
• 2015

식물은 다양한 생화학적 및 생리적 과정에 속한 유전자들의 발현 수준을 조절함으로써 저온 스트레스에 반응 및 적응을 할 수 있다. 이러한 스트레스 환경은 막 기능 손실, 세포벽의 변화, 대사 속도 변화 등과 같이 부정적인 영향을 초래한다. 따라서 본 연구는 배추(Brassica rapa ssp. pekinensis)에서의 시간 변화에 따른 저온 스트레스 반응 기작 관련 유전자 상호발현 네트워크를 구축하였다. 배추의 저온 스트레스 네트워크는 2,030개 node, 20,235개 edge, 및 34개 connected component로 구성되었으며, 구축된 네트워크는 배추에서 저온에 관여하는 유전자가 생육도 조절한다는 것을 보여 주었다. 구축한 네트워크를 이용하여 배추에서 저온 스트레스($4^{\circ}C$) 처리가 미치는 영향을 분석한 결과 WRKY 전사인자와 살리실산 신호에 의해 chitinase 부동 단백질이 활성화되고, 전신적 획득저항성을 작동하기 위해 기공 개폐 및 탄수화물 대사과정이 조절됨을 확인하였다. 또한 저온 처리 후 48시간 후에 저온 스트레스가 영양생장에서 생식 생장 및 분열 조직 단계의 변화를 초래하는 것으로 나타났다. 본 연구에서 구축한 네트워크 모델은 배추에서 저온 저항성 관련 유전자들의 발현 패턴을 정확히 유추하는 데 이용될 수 있을 것이다.

• 환경생물
• /
• 제29권4호
• /
• pp.258-264
• /
• 2011

Glutathione (GSH)은 직접적으로 활성산소종을 제거하거나 GSH peroxidase와 같은 활성산소종 제거 효소의 조효소로써, 산화적 스트레스로부터 세포를 방어하는 데 중요한 역할을 한다. GSH peroxidase는 두 분자의 GSH을 이용해 세포 내 과산화수소를 물로 전환한다. $N$-acetyl-L cysteine (NAC)는 항산화제 중 하나로 세포 내 GSH의 전구물질로 이용된다. 본 연구는, 0mM에서 20mM의 NAC 단독 처리 또는 100 Gy 감마선과 복합 처리한 효모세포에서 GSH peroxidase를 코드화(encoding)하는 유전자인 $GPX1$과 $GPX2$의 전사적 발현을 통해 GSH, NAC와 GSH peroxidase의 연관성을 알아보았다. $GPX1$과 $GPX2$의 전사적 발현은 NAC와 100 Gy 감마선에 의해 유도되었다. 조사된 효모세포에서 NAC의 증가 농도에 따라 GSH peroxidase 두 유전자의 발현은 감소되었다. 이러한 결과로, NAC에 의해 증가된 세포 내 GSH는 GSH peroxidase 유전자의 전사적 발현을 유도하며, NAC는 감마선으로부터 생성된 활성산소종 직접적 제거와 GSH peroxidase 유전자의 전사적 발현을 유도함으로써 세포를 보호할 수 있다는 것이 밝혀졌다.

• Journal of Plant Biotechnology
• /
• 제42권2호
• /
• pp.88-92
• /
• 2015

카사바는 열대와 아열대지역 뿌리작물로서 중요한 식량자원일 뿐만 아니라 동물 사료, 전분, 바이오에탄올 등 다양한 산업소재로서 이용이 가능하다. 그러나 카사바의 산업적 중요성에 비해 형질전환기술을 이용한 신품종 개발은 아직까지 제한적이다. 본 연구에서는 인도네시아 IDB사가 개발한 다수확 카사바 품종을 이용하여 영양강화 및 환경스트레스에 저항성을 향상시킨 카사바를 개발하기 위하여 체세포배를 이용한 식물체 재분화시스템을 확립하였다. 카로티노이드 축적에 관련된 IbOr 유전자를 체세포배를 이용한 Agrobacterium 매개방법으로 카사바에 형질전환하였다. gDNA PCR과 RT-PCR을 통해 19개의 형질전환식물체를 성공적으로 확보하였다. 향후 카로티노이드 함량분석, 환경스트레스 내성분석 등을 통하여 IbOr 카사바 식물체의 농업적 유용성을 검정할 예정이다.