• 한국자원식물학회지
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• 제31권6호
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• pp.684-694
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• 2018

This study describes the successful establishment of a cryopreservation protocol for Citrus limon cultivars: 'Frost Eureka limon' and 'Cook Eureka limon', using a droplet-vitrification method. The shoot tips that were excised from in vitro grown seedlings of the two cultivars were preserved in liquid nitrogen (LN) and successfully regenerated into whole plants. Excised shoot tips were pre-cultured for 1 or 2 days in 0.3 M and 0.5 M sucrose solutions at $25^{\circ}C$ and incubated in a loading solution (LS) composed of 17.5% glycerol + 17.5% sucrose in Murashige and Skoog (MS) medium for 40 min at $25^{\circ}C$. Prior to direct immersion in LN for 1 h, the shoot tips were dehydrated with plant vitrification solution 2 (PVS2) at $0^{\circ}C$ or PVS3 at $25^{\circ}C$. The frozen shoot tips were re-warmed and unloaded with 1.2 M sucrose in $\text\tiny{^1/_2}$ MS for 30 min at $25^{\circ}C$. Shoot tips were post-cultured overnight on survival medium and then micrografted onto 'trifoliate orange' (Poncirus trifoliate (L.) Raf. seedling rootstocks for recovery and to produce whole plants. The highest regrowth rates were 53.5% and 50.3% for cryopreserved shoot tips of 'Frost Eureka limon' and 'Cook Eureka limon', respectively, when pre-cultured in 0.3 M and 0.5 M sucrose concentrations in a sequencing manner, with LS and treated with PVS2 for 60 min at $0^{\circ}C$. We also investigated whether the ammonium ion concentration on post-culture medium affected the viability of the cryopreserved Citrus shoot tips. The viability of cooled samples, following culturing on woody plant media (WPM) containing $\text\tiny{^1/_4}$ ammonium nitrate overnight before micrografting, was the highest (70.3%) in 'Frost Eureka limon'. The study described here is a cost-effective and safe method to conserve Citrus fruit cultivars, for the improvement and large-scale multiplication of fruit plants and for breeding disease resistance.

• The Plant Pathology Journal
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• 제28권2호
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• pp.207-211
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• 2012

It has been known that streptomycin resistance in bacteria can occur as a results of chromosomal mutation or through gene acquisition or both. Chromosomal mutations for resistances are point mutations in the rpsL gene, which alter ribosomal protein S12. Acquired resistance has occurred when an $Sm^R$ plasmid carrying transposon Tn5393 with tandem strA-strB gene is transferred by conjugation. A total of 686 isolates of Xanthomonas smithii subsp. citri causal agent of citrus canker disease were collected from 26 citrus orchards in Jeju Island in 2003 and 2004 seasons. Forty-nine of 111 isolates from streptomycin non-sprayed orchards in 2003 season were resistant to streptomycin. Of 107 isolates from orchards sprayed one time with streptomycin, 58 isolates were resistant, and 166 of 221 isolates from orchards sprayed two times with streptomycin were resistant. In 12 orchards sprayed three or more times with streptomycin, 219 of 247 isolates were resistant to streptomycin. Twenty-five isolates of X. smithii subsp. citri were surveyed to identify the mechanisms of streptomycin resistance in this study. Twenty-one of these 25 isolates were resistant to streptomycin, and it was proven by PCR assay that 18 of the 21 streptomycin resistant isolates have the strB gene. In sixteen of the 21 streptomycin resistant isolates, it was occurred a point mutation altered codon lysine (AAG)-41 of rpsL gene to arginine (AGG). The streptomycin-sensitive isolates easily acquired the resistance by mixed culture with resistant isolates. The strB gene was amplified from the isolates that acquired the resistance by mixed culture, and one isolate of them was also point-mutated in codon 41 of rpsL gene to be resistant. In this study, most of the streptomycin-resistant isolates of X. smithii sub sp. citri in Jeju island expressed the resistance by both chromosomal point mutation and gene acquisition, and the resistance was easily acquired through conjugation by culture mixed with streptomycin resistant and sensitive strains.

• 한국식물병리학회:학술대회논문집
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• 한국식물병리학회 2002년도 총회 및 추계학술발표회
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• pp.94.1-95
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• 2002

• The Plant Pathology Journal
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• 제39권3호
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• pp.265-274
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• 2023

Citrus black rot is a serious disease of citrus plants caused by Alternaria citri. The current study aimed to synthesize zinc oxide nanoparticles (ZnO-NPs) by chemically or green method and investigate their antifungal activity against A. citri. The sizes of synthesized as measured by transmission electron microscope of ZnO-NPs were 88 and 65 nm for chemical and green methods, respectively. The studied prepared ZnO-NPs were applied, in vitro and in situ, at different concentrations (500, 1,000, and 2,000 ㎍/ml) in post-harvest treatment on navel orange fruits to verify the possible control effect against A. citri. Results of in vitro assay demonstrated that, at concentration 2,000 ㎍/ml, the green ZnO-NPs was able to inhibit about 61% of the fungal growth followed by 52% of chemical ZnO-NPs. In addition, scanning electron microscopy of A. citri treated in vitro with green ZnO-NPs showed swelling and deformation of conidia. Results showed also that, using a chemically and green ZnO-NPs at 2,000 ㎍/ml in situ in post-harvest treatment of orange, artificially-infected with A. citri, has reduced the disease severity to 6.92% and 9.23%, respectively, compared to 23.84% of positive control (non-treated fruits) after 20 days of storage. The out findings of this study may contribute to the development of a natural, effective, and eco-friendly strategy for eradicating harmful phytopathogenic fungi.

• Asian Pacific Journal of Cancer Prevention
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• 제16권6호
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• pp.2575-2580
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• 2015

Cancer is a multifaceted and genomically complex disease and rapidly accumulating high impact research is deepening our understanding related to the mechanisms underlying cancer development, progression and resistance to therapeutics. Increasingly it is being realized that genetic/epigenetic mutations, inactivation of tumor suppressor genes, overexpression of oncogenes, deregulation of intracellular signaling cascades and loss of apoptosis are some of the extensively studied aspects. Confluence of information suggested that rapidly developing resistance to therapeutics is adding another layer of complexity and overwhelmingly increasing preclinical studies are identifying different natural agents with efficacy and minimal off-target effects. We partition this multi-component review into citrus fruits and their bioactive ingredients mediating rebalancing of pro- and anti-apoptotic proteins to induce apoptosis in resistant cancer cells. We also discuss how oncogenic protein networks are targeted in cancer cells and how these findings may be verified in preclinical studies.

• 농약과학회지
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• 제13권4호
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• pp.332-335
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• 2009

유기농 인증을 받아서 3년 이상이 경과한 농가의 토양을 수집하여 근권 세균을 450균주 분리하였고, 여러 가지 식물 병원균의 균사 생장을 억제하는 세균 KB-401 균주를 선발하였다. KB-401 균주는 특히 감귤 검은점무늬병균(Diaporthe citri)의 균사 생장과 포자 발아를 억제하며, 발아하는 포자에 처리하였을 때 발아관의 선단이 팽윤되는 현상을 관찰할 수 있었다. 본 균주는 생리적인 특성과 16S rDNA의 염기서열을 분석한 결과, Bacillus subtilis로 동정되었다.

• Journal of Nutrition and Health
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• 제49권3호
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• pp.144-152
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• 2016

본 연구는 귤피가루를 활용하여 모닝빵을 개발하고 이를 대학기숙사에 거주하고 있는 과체중 및 비만인 20대 남 녀에게 섭취하게 해봄으로써 아침결식률을 낮출 수 있는 새로운 식품 소재를 개발하고자 실시되었다. 체중과 BMI의 경우 GB 섭취군과 CPB 섭취군 모두에서 감소하였으며, CPB 섭취군에서 사전에 비해 사후 유의적으로 체중과 BMI가 감소한 것으로 나타났다 (p < 0.05). WHR은 GB 섭취군에서는 증가하는 경향을 보였으나 CPB 섭취군에서는 유의적으로 감소하였다 (p < 0.05). BFM은 두군 모두에서 유의적으로 증가하였으며 (p < 0.05) 군간에 유의성을 띄지 않았다. TC는 GB 섭취군에서는 증가하는 경향을 보였으나 CPB 섭취군에서는 유의적으로 감소하였다 (p < 0.05). HDL은 두군 모두에서 증가하였고 GB 섭취군에서 유의성을 보였다 (p < 0.05). LDL은 두군 모두에서 유의적으로 감소하였으며 (p < 0.05) 군간에 유의성은 없었다. GOT와 GPT는 GB 섭취군과 CPB 섭취군 모두에서 감소하였고 CPB 섭취군에서 유의성을 보였다 (p < 0.05). GB와 CPB를 섭취한 군간에 신체계측치와 혈액생화학적 수치에서 유의적인 차이를 보이는 항목은 없었으나 CPB 섭취군에서 사전에 비해 TC, LDL, GOT, GPT 수치가 유의적으로 감소하였다는 점에서 (p < 0.05) 본 연구는 시간적 흐름에 따라 변화를 추적하는 종단적 연구에 가깝다고 판단되며 본 연구를 통하여서 귤피가 심혈관계질환의 유병률을 낮춰줄 수 있는 잠재적 가능성이 있음을 임상적으로 확인하였다. 따라서 향후 본 연구와 유사한 연구들이 double blind cross-over study와 같은 대규모 임상연구로 진행되어 귤피의 지질관련 효과들을 보다 명확하게 입증해줄 필요성이 있을 것으로 판단된다.

• 식물병연구
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• 제29권4호
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• pp.459-463
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• 2023

정서적 안정과 휴식에 효과적이며, 공기 정화 등 기능성을 가진 관엽식물에 대한 수요가 증가하고 있으나, 관엽식물에 피해를 유발할 수 있는 식물기생선충에 대한 연구는 전무한 실정이다. 본 연구는 국내 판매되고 있는 관엽식물에서 발생하는 식물기생선충의 검출 여부와 밀도를 파악하고자 관엽식물과 작물재배지에 대해 2022년 7월부터 12월까지 모니터링을 수행하였다. 415개의 관엽식물과 국내 24개 차나무 및 22개 감귤재배지의 식물기생선충을 조사하였다. 관엽식물 내 식물기생선충 조사 결과, 뿌리썩이선충이 가장 많이 검출되었으며, 잎선충, 뿌리혹선충, 침선충이 확인되었다. 차나무재배지에서는 나선선충, 씨스트선충, 뿌리혹선충, 뿌리썩이선충이 검출되었고, 감귤재배지에서는 감귤선충, 주름선충, 뿌리썩이선충, 뿌리혹선충 등이 검출되었다. 관엽식물, 차나무 및 감귤 재배지에서 뿌리썩이선충이 가장 우려되는 식물기생선충이었으나, 뿌리혹선충, 씨스트선충이 일부 검출되어 피해가 우려되므로 온탕침법, 유기농업자재의 사용, 잡초제거 등 식물기생선충의 방제 방법을 재배에 적용하여야 할 것이다.

• 한국균학회지
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• 제30권2호
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• pp.166-169
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• 2002

2002년 진주시 농산물 도매시장에서 Rhizopus stolonifer에 의한 감귤 무름병이 발생하였다. 병징은 처음 과일 껍질 부분이 수침상으로 물러지면서 급속히 진전되어 썩었다. 균사는 처음 흰색에서 연한 갈색으로 되며 검은색의 포자낭을 형성한다. 포자낭병은 처음 무색에서 회색을 나타내며 포자낭을 끝에 만들고 길이는 $900{\sim}4300{\mu}m$였다. 포자낭은 처음에 무색에서 나중에 검은색이고 아구형으로 크기는 $98{\sim}346{\mu}m$이다. 추축은 아구형 또는 타원형으로 직경은 $60{\sim}216{\times}72{\sim}143{\mu}m$이다. 포자낭포자는 담갈색으로 단포이며 구형 또는 타원형으로 크기는 $8{\sim}18.3{\mu}m$였다. 균사생육 적온은 $25^{\circ}C$였다. 이상과 같이 병원균의 균학적 특징과 병원성을 검정한 결과 이병을 R. stolonifer에 의한 감귤 무름병으로 명명할 것을 제안하고자 한다.

• 동의생리병리학회지
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• 제22권1호
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• pp.96-99
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• 2008

Toxoplasma gondiiis a widespread apicomplexan parasite which is able to infect virtually all warm-blooded vertebrates. Twenty-two percent of the U.S. population is infected, but severe disease in adults is mainly limited to immunosuppressed patients. In patients with acquired immunodeficiency syndrome(AIDS), T. gondii causes a life-threatening opportunistic infection, with Toxoplasma encephalitis as its most severe manifestations. T. gondii is also known to cause congenital infection and is among the pathogens with the highest incidence of complications in pregnancies. Despite its clinical importance, only very few therapeutic drugs against T. gondii are available, all of which target the rapidly dividing tachyzoites, leaving the dormant encysted bradyzoite stage unaffected. We searched 15 traditional medicines that have anti-inflammatory effect from dongyibogam and Traditional Chinese medicine. In vitro studies were performed with HeLa cell cultures, with quantification of Toxoplasma growth by a cell proliferation assay. The result of experiment shows the selectivity of Citrus unshiu Markovich is 6.0. This is higher than sulfadiazine (selectivity was 1.63). For in vivo studies, mice were acutely infected intraperitoneally with $10^5$ tachyzoites of the virulent RH strain and then treated per orally for 4 days from 6 hours postinfection. Efficacy was assessed by sequential determination of parasite burdens in peritoneal cavity. In vivo, Citrus unshiu Markoviche inhibited Toxoplasma growth at a concentration of 10㎎/㎏ of body weight per day, the inhibition ratio was estimated to be 64.01%.