Development of Multiplex PCR for Simultaneous Detection of Citrus Viruses and the Incidence of Citrus Viral Diseases in Late-Maturity Citrus Trees in Jeju Island

현재욱,황록연,정경은 한국식물병리학회 2017 Plant Pathology Journal Vol.33 No.3

Satsuma dwarf virus (SDV) or Citrus mosaic sadwavirus (CiMV) were not consistently detected in RTPCR assay with the primer sets based on gene of Japan isolates. SDV and CiMV isolates were distinctively divided into two groups based on phylogenetic analysis of PP2 gene cloned from 22 Korean isolates, and the Korean CiMV and SDV isolates shared 95.5–96.2% and 97.1–97.7% sequence identity with Japanese isolate, respectively. We developed PP2-1 primer set based on the PP2 gene sequence of Korean isolates to simultaneously and effectively detect SDV and CiMV. And CTLV-2013 and CTV-po primer sets were newly designed for detection of Citrus tatter leaf virus (CTLV) and Citrus tristeza virus (CTV), respectively. Using these primer sets, a new multiplex PCR assay was developed as a means to simultaneously detect 4 citrus viruses, CTV, CTLV, SDV, and CiMV. The degree of detection by the multiplex PCR were consistent with those of uniplex RT-PCR for detection of each of the viruses. Therefore, the new multiplex PCR provides an efficient method for detecting 4 citrus viruses, which will help diagnose many citrus plants at the same time. We verified that 35.2% and 72.1% of 775 trees in 155 orchards were infected with SDV or CiMV (SDV/CiMV) and CTV by the multiplex-PCR assay, respectively, and CTLV was not detected in any of the trees tested.

Improved Method to Increase Conidia Production from Isolates of Different Pathotypes of Citrus Scab Pathogen Elsinoe spp

현재욱,Dilli Prasad Paudyal,황록연 한국식물병리학회 2015 식물병연구 Vol.21 No.3

Elsinoe fawcettii and E. australis are two currently recognized scab pathogens of citrus. E. fawcettii has at least six pathotypes while E. australis has at least two pathotypes. Colonies of E. fawcettii and E. australis do not sporulate in artificial media including potato dextrose agar (PDA). Whiteside’s method has been widely used for preparing conidial inoculum in vitro. This study was carried out to develop efficient method for conidia production from artificial media. We developed a shaking method which included the following steps: 1) Colony grown on PDA was mashed with a steel spatula; 2) Mycelia fragments were cultured in 50 ml sterilized rain water in a rotary shaker-incubator (180 rpm) at 25ºC for 24 h: 3) The conidia suspension was filtered through two layers of cheesecloth. Average conidia production of all isolates tested using this shaking method was approximately 13.1 times higher than that from Whiteside’s method in this study.

BMD42-2910, a Novel Benzoxazole Derivative, Shows a Potent Anti-prion Activity and Prolongs the Mean Survival in an Animal Model of Prion Disease

현재욱,노란,최지원,이솔뫼,이영선,안성수,노경태,이정민 한국뇌신경과학회 2020 Experimental Neurobiology Vol.29 No.1

Prion diseases are a group of neurodegenerative and fatal central nervous system disorders. The pathogenic mechanism involves the conversion of cellular prion protein (PrPC ) to an altered scrapie isoform (PrPSc), which accumulates in amyloid deposits in the brain. However, no therapeutic drugs have demonstrated efficacy in clinical trials. We previously reported that BMD42-29, a synthetic compound discovered in silico, is a novel anti-prion compound that inhibits the conversion of PrPC to protease K (PK)-resistant PrPSc fragments (PrPres). In the present study, 14 derivatives of BMD42-29 were obtained from BMD42-29 by modifying in the side chain by in silico feedback, with the aim to determine whether they improve anti-prion activity. These derivatives were assessed in a PrPSc-infected cell model and some derivatives were further tested using real timequaking induced conversion (RT-QuIC). Among them, BMD42-2910 showed high anti-prion activity at low concentrations in vitro and also no toxic effects in a mouse model. Interestingly, abundant PrPres was reduced in brains of mice infected with prion strain when treated with BMD42- 2910, and the mice survived longer than control mice and even that treated with BMD42-29. Finally, high binding affinity was predicted in the virtual binding sites (Asn159, Gln 160, Lys194, and Glu196) when PrPC was combined with BMD-42-2910. Our findings showed that BMD42-2910 sufficiently reduces PrPres generation in vitro and in vivo and may be a promising novel anti-prion compound.

경제학은 과학인가?

현재욱 인물과사상사 2016 인물과 사상 Vol.- No.222

불행을 먹고 자라는 월가의 민낯

현재욱 인물과사상사 2016 인물과 사상 Vol.- No.223

노지재배 감귤에서의 볼록총채벌레 발생 양상과 피해 증상

현재욱,황록연,이관석,송정흡,이평호,권혁모,현동희,김광식,Hyun, Jae-Wook,Hwang, Rok-Yeon,Lee, Kwan-Seok,Song, Jeong-Heub,Yi, Pyoung-Ho,Kwon, Hyeog-Mo,Hyun, Dong-Hee,Kim, Kwang-Sik 한국응용곤충학회 2012 한국응용곤충학회지 Vol.51 No.1

최근 들어 노지재배 감귤에서 볼록총채벌레에 의해 검은점무늬병 후기 증상 및 녹응애 피해 증상과 매우 유사하게 과정부 주위를 중심으로 검붉게 그을린 증상 또는 조직이 회갈색으로 괴사되어 딱지형태가 되는 증상들이 2007년부터 서귀포시 남원읍 일부지역에 발생하여 큰 피해를 주고 있다. 황색 끈끈이 트랩을 이용하여 7일 마다 발생 밀도를 조사한 결과 2009년의 경우 5월 상순부터 발생하기 시작하여 꾸준히 증가하다 8월 하순에 밀도가 가장 높았으며 2010년과 2011년의 경우 10월 상순에 밀도가 가장 높았다. 2009년의 경우 5월부터 10월 하순까지 최소 7회의 발생 세대를 보였고 통상 7월 경부터 볼록총채벌레가 감귤원에서 우점하여 발생하였다. 과실에서 볼록총채벌레 약충들이 7월부터 발견되어 2009년의 경우 8월 하순부터 9월 중순, 그리고 10월 상순에 피크를 보였고 피해 증상은 9월 중순부터 발생하기 시작하였다. 2011년의 경우 7월 상순에 밀도가 매우 높았으며 이후 9월 하순에 다시 밀도가 증가하였고 피해 증상은 7월 중하순 부터 발생하기 시작하여 10월 하순까지 계속적으로 증가하였다. 피해증상은 과정부를 중심으로 회색빛으로 부스럼같이 코르크화 되거나 초기에 검은색을 띄다가 착색기에 접어들어 과피가 검붉게 변하였다. 감귤에서 볼록총채벌레에 의한 이런 피해 증상을 국내에 처음으로 보고한다. Silver-grey or dark brown scaring, or dark brown discolored damages caused by the yellow tea thrip, $Scirtothrips$ $dorsalis$ Hood (Thysanoptera: Thripidae) have occurred on citrus fruits cultivated in the open field in east-south area orchards of Jeju Island since 2007. The weekly population of yellow tea thrips adults caught with a yellow sticky trap increased gradually from early May and peaked in late August, 2009. In 2010 and 2011, the most population was in early October. The yellow tea thrips of some species usually dominated from July in open citrus fields, and seven generations, at least, had occurred from May to late October 2009 by a yellow sticky trap survey. In 2009, $S.$ $dorsalis$ larva were observed from July and with peaks from late August to mid September and early October on citrus fruits. The damage symptoms appeared in the mid September. In 2011, the population peaks were in early July and late September, and the symptoms increased continually from mid July to late October. The symptoms were silver-scars or initial dark discolorations and then gradually changed to dark-brown discolorations or dark-brown scars. The percent of damaged fruits were 0.9%, 0.4%, 0.8% and 2.7% in 2008, 2009, 2010 and 2011, respectively, by survey in 64 typical orchards in Jeju Island. We are the first to report symptoms of the yellow tea thrip ($Scirtothrips$ $dotsalis$) on citrus fruits.

숲의 경제학

현재욱 인물과사상사 2017 인물과 사상 Vol.- No.228

누구를 위하여 금리는 오르는가?

현재욱 인물과사상사 2017 인물과 사상 Vol.- No.229

식량위기는 어떻게 오는가?

현재욱 인물과사상사 2016 인물과 사상 Vol.- No.221

최근 주요 감귤 병의 발생 양상

현재욱,이평호,황록연,문경환 한국식물병리학회 2013 식물병연구 Vol.19 No.2

The percent of diseased fruit by Diaporthe citri was the most 16.8% in 2010 and the least 3.8% in 2005, and the average was 8.8% from 2003 to 2012. The degrees of disease incidence were relatively high, 17.0, 22.6, 19.2and 18.9%, in 2003, 2004, 2007 and 2010, respectively. The percent of diseased fruit by Elsinoe fawcettii was the most 0.72% in 2004, and then gradually decreased to 0.08% in 2008, and the average was from 0.28%from 2004 to 2011. In case of canker by Xanthomonas citri subsp. citri, the percent of diseased fruit was the most 2.19% in 2004, and gradually decreased to 0.08 and 0.10% in 2009 and 2010, respectively. The average was 0.81% from 2004 to 2012. The melanose by D. citri was most in south-east area of Jeju Island, and east and west in case of canker. The melanose symptoms were initially appeared from mid June, mainly peaked late of July to late August. The canker symptoms were initially produced on leaves of natsudaidai and grapefruit cultivated in open field middle of June in 2010 and 2011 and late of May in 2012. The scab disease was firstly appeared approx. early or mid May and then rapidly increased late of May to middle of June. The inoculum was mainly produced from dead twigs late June to early of August. 2003년도부터 감귤검은점무늬병에 걸린 과실율을 조사해 본 결과 2010년에 16.8%로써 가장 심하였으며 2005년에는 3.8%로써 가장 낮았고 10년간 평균 병든 과율은8.8%이었다. 지역별로 최근 10년 동안 병든 과율을 비교해 보면 제주도 남동부, 동부지역에서 병 발생이 많았다. 또한 발병도를 조사해 본 결과 2003, 2004, 2007, 2010년 검은점무늬병 발병도가 각각 17.0, 22.6, 19.2, 18.9%로써 다른 해에 비하여 발병도가 높았다. 궤양병의 경우2004년에 2.19% 발병하여 최근 들어 가장 많이 발생하였으며 그 이후로 급격히 줄어들어 2009년과 2010년의경우 0.08와 0.10%이었지만, 2011년의 경우 1.50%로써다시 증가하였으며 2004년부터 2012년까지 평균 발생율은 0.81%이었다. 또한 발생 지역도 제주도 동부와 서부지역에서 많았다. 더뎅이병의 경우 2004년부터 2012년까지 9년간 평균 발생과율은 0.25% 이었으며 2004년 0.72%로 가장 발생이 많았다. 감귤 과실에서의 검은점무늬병진전 상황을 조사해 본 결과 해에 따라 약간씩 상이하지만 7월 하순부터 8월 하순까지 병 진전이 가장 많았다. 더뎅이병의 경우 5월 10일경에 첫 병징이 나타났으며 이후 5월 하순에서 6월 중순사이에 급격히 증가하였다. 궤양병의 경우 6월 중순경에 첫 병징이 나타나서 6월 하순까지 봄순에서 병이 진전되었다. 죽은 가지에서 검은점무늬병 전염원 주 발생 시기는 6월 하순부터 8월 상순경이었다.