살비제 저항성 표현형 및 유전형 간의 상관분석을 통한 점박이응애 저항성 관련 마커 선발

권덕호 한국농약과학회 2023 한국농약과학회 학술발표대회 논문집 Vol.2023 No.11

딸기 시설 하우스 점박이응애에 대한 살비 효과 평가

권덕호,안율균,홍규현,Kwon, D.H.,Ahn, Y.K.,Hong, K.H. 국립한국농수산대학교 교육개발센터 2020 현장농수산연구지 Vol.22 No.2

In the strawberry cultivation areas and domestic farms, two-spotted spider mites are the most serious pests. It decreases the product yield due to the direct feeding of chlorophyll by the mites resulting in reduced photosynthetic ability of host plant. In this study, a simplified acaricidal effect evaluation system (SAEES) was employed to choose the effective acaricidal products among 10 items based on leaf-dipping bioassay methods. SAEES had the advantage of being able to screen four commercial products with three replications at the same time in the recommended concentration. The susceptible strains (SL_YS) showed a high mortality rate of about 90-100%, whereas the mortality of local strains was differed by each acaricides. It suggests that the acaricide responses of field populations might differ due to spray frequencies and acaricide product. An efficacy index (0.8-1.0) was determined based on the mortality of susceptible strain, which would allow the most effective commercial products to be selected by the range of this index. In summary, SAEES will enable the selection of effective commercial products and contribute to increasing control against T. urticae in strawberries.

Genetic diversity and structure in apple-infesting pests of Carposina sasakii, Grapholita dimorpha and Grapholita molesta in Korea

권덕호,김동환,김형환,이시혁,양창열 한국응용곤충학회 2017 Journal of Asia-Pacific Entomology Vol.20 No.1

The genetic diversity of three apple-infesting pests, Carposina sasakii, Grapholita dimorpha and Grapholitamolesta, found in four local regions in Korea,was investigated using the mitochondrial cytochrome c oxidase I (COI) gene as amarker. Six, seven, and three larval haplotypes fromC. sasakii, G. dimorpha, and G. molesta, respectively,were observed. The haplotype and nucleotide diversitywere ranged as 0.31–0.69 and 0.0006–0.0040, respectively. The estimates of genetic differentiation (FST) among local populations in C. sasakii and G. dimorpha exhibited very narrowrange differentiation as 0 to 0.025 and 0 to 0.075, respectively,whereas G. molesta revealed amoderate range of genetic distance (FST=0–0.461). In the AMOVA analysis, low percent variations (0–0.98%) and FST values (0 and 0.01, respectively) observed in C. sasakii and G. dimorpha, respectively,whereas G. molesta revealedmoderate diversity as 31.3% (FST=0.313, p=0.038). These results would provide the basic information to understand the difference of genetic structure in species level and further be utilized to estimate the temporal and spatial distribution of these species in apple orchard.

전사체 분석 기반 꽃노랑총채벌레 살충제 저항성 기작 규명

권덕호 한국응용곤충학회 2017 한국응용곤충학회 학술대회논문집 Vol.2017 No.10

꽃노랑총채벌레의 약제 저항성 유전자 마커를 발굴하기 위해 전사체 분석을 통해 감수성과 저항성 계통의 발현량차이를 분석해 보았다. 저항성 계통은 4종의 약제에 대해 약 39.2 ~ 533-fold의 복합저항성을 보였으며, 전사체분석 결과 감수성 계통 대비 약 630여개의 유전자가 2배 이상(FDR < 0.001) 발현량 차이를 보이는 것으로 확인되었다.Gene ontology 분석 결과, 과발현 유전자가 biological process, molecular function, cellular function 그룹 별로 각각60%, 68.6% 그리고 70.6% 차지하였다. 특히, 대사와 유기화합물 결합단백질 관련 유전자(ex. CYP450, GST, EST,etc.)는 저항성 발달에 관여하는 것으로 사료된다. 추가적인 모니터링과 상관관계 분석을 통해 해당 유전자의 기능검정이 필요하며, 이 중에서 높은 상관성을 나타내는 유전자는 약제 저항성 진단 마커로 활용이 가능할 것이다.

Xylose Fermentation Was Improved by Kluyveromyces marxianus KHM89 through Up-regulation of Nicotinamide Adenine Dinucleotide (NAD+) Salvage Pathway

권덕호,하석진 한국생물공학회 2022 Biotechnology and Bioprocess Engineering Vol.27 No.4

Xylose fermentation has been reported to be improved in Kluyveromyces marxianus via strain improvement by overexpressing xylose reductase (XYL1) and xylitol dehydrogenase (XYL2). This study performed directed evolution to further enhance xylose consumption in a K. marxianus mutant following transcriptomic analysis to determine genes associated with enhanced characteristics. KmXYL1 and KmXYL2 genes were overexpressed in K. marxianus 17555ΔURA3 for improving xylose fermentation. By performing directed evolution, a mutant K. marxianus KHM89 showing enhanced ethanol production was isolated from xylose medium. K. marxianus KHM89 consumed 47.39 g/L of xylose and produced 22.62 g/L of xylitol and 10.59 g/L of ethanol while the parental strain consumed 25.15 g/L of xylose and produced 7.36 g/L of xylitol and 2.05 g/L of ethanol. RNA sequencing-based transcriptomic analysis showed that alcohol dehydrogenases, aldehyde dehydrogenases, and NAD+ salvage pathway enzymes were upregulated in K. marxianus KHM89. These results were achieved via a combinatorial approach of rational design and directed evolution. The findings of this study contribute to the improvement of xylose fermentation by K. marxianus at an industrial scale.

Plasma-based organism evaluation equipment using atmospheric-pressure plasma jets: Efficacy for controlling insect pests

권덕호,김현승,박미리 한국응용곤충학회 2019 Journal of Asia-Pacific Entomology Vol.22 No.3

Alternative insect pest control methods are necessary for efficient pest management with reduced dependency on pesticides. Here, we report the biological responses of several insect species to, and the insecticidal efficacy of, reactive oxygen species (ROS) generated using atmospheric-pressure plasma jets. Plasma-based organism evaluation equipment (PBOEE) consisting of a plasma-generating acrylic chamber, plasma-maintaining acrylic chamber, and plasma efficacy evaluation container was developed. The PBOEE system enabled determination of the insecticidal efficacy of ROS free from the adverse effects of high temperature; moreover, four different exposures could be achieved within one run. The biological responses of five major insect pests (Aphis gossypii, Bemisia tabaci, Helicoverpa armigera, Tetranychus kanzawai, and Thrips palmi) were assessed, with a focus on knockdown time, recovery time, and median lethal time (LT 50 ). With short-term exposure (< 3 min), B. tabaci showed the fastest knockdown time (38.4 ± 2.7 s) and the slowest recovery time (699 ± 133 s), and no mortality was noted in any of the five species. On the other hand, with long-term exposure (< 21 min), insecticidal efficacy was observed in B. tabaci and T. palmi, which showed LT 50 values of 6.3 and 9.6 min, respectively. The PBOEE system can be used to determine the optimal exposure time for evaluating the insecticidal efficacy of plasma against insect pests, and plasma can be used for future control of some insect pests.

F331H mutation and reduced mRNA in type-1 acetylcholinesterase is associated with carbofuran resistance development in the small brown planthopper (Laodelphax striatellus Fallén)

권덕호,김형범,정인홍,이시혁 한국응용곤충학회 2019 Journal of Asia-Pacific Entomology Vol.22 No.1

Molecular diagnostic markers are necessary for establishing high-throughput screening systems to support insecticide-resistant population management. Here, we identified single amino acid substitution mutations related to carbamate resistance in Laodelphax striatellus Fallén type-1 acetylcholinesterase (LsAChE1) using carbofuranselected strains. The phenotypic resistance profiles of the final selection strain (SEL9) compared to the susceptible strain revealed a 14-fold higher resistance ratio based on topical application, 1.2-fold higher general esterase activity, and 4.3-fold higher acetylcholinesterase insensitivity based on the 50% inhibitory concentration (I 50 ), suggesting that insensitivity of the target site could occur as a resistance factor. Comparison of the nucleotide sequences of Lsace1 of five strains (SUS, SEL0, SEL3, SEL6, and SEL9) revealed two amino acid substitutions (F330Y and F331H). To understand the roles of these mutations, we determined the allele frequency of both point mutations in the selected strains using quantitative sequencing methods. In addition, several quantitative genotypic traits (e.g., gene copy numbers and transcript levels of Lsace1, Lsace2, and LS.CarE1) were assessed. A correlation analysis of genotypic and phenotypic traits revealed strong correlations between resistance level and I 50 with F331H allele frequency. Interestingly, the F331H mutation was negatively correlated with transcript levels of Lsace1, suggesting that selection pressure might result in a reduction of the target gene. Overall, the F331H mutation and reduced mRNA are important factors in the development of carbamate resistance. Furthermore, the point mutation can be used to monitor rapid carbofuran resistance in conjunction with molecular diagnostic methods such as quantitative sequencing.

CRISPR-Cas9 system을 이용한 Kluyveromyces marxianus 17694-DH2 균주의 자일로스 소비속도 증진

권덕호,박중희,정덕열,박재범,박동민,강경곤,최서영,김수린,하석진 한국생물공학회 2019 KSBB Journal Vol.34 No.4

The third-generation gene editing technology, CRISPR-Cas9 system, is derived from the bacterial immune system. These CRISPR-Cas9 systems have recently been used to mutate yeast gene or replace cleavage sites with other DNA. In this study, CRISPR-Cas9 system was applied to delete PHO13 gene of Kluyveromyces marxianus. As a result, only one strain of three transformants, that the CRISPR-Cas9 system was applied, was confirmed partial deletion of PHO13 gene. Sequencing of the PHO13 gene revealed the deletion of cytosine at position 457, which resulted in premature termination of translation as compared to that from the parental strain. The ΔPHO13 strain, K. marxianus 17694-DH2, showed 18.29% and 21.28% improvement in xylose consumption and ethanol production from xylose, respectively, as compared to those form the parental strain.

Multiple resistance mechanisms to abamectin in the two-spotted spider mite

권덕호,Geon Mook Seong,강택준,이시혁 한국응용곤충학회 2010 Journal of Asia-Pacific Entomology Vol.13 No.3

The two-spotted spider mite, Tetranychus urticae, is one of the most destructive pests of various orchard trees and garden plants. Biochemical mechanisms of abamectin resistance in two T. urticae strains (PTF, 239-fold resistance; AbaR, ca. 4753-fold resistance) were investigated. The involvement of both esterase (Est) and mixed function oxidase (MFO) in abamectin resistance was suggested by synergistic bioassays, in which median lethal time (LT50) values were significantly reduced by pretreatment with triphenyl phosphate (TPP)and piperonyl butoxide, respectively. Detoxification enzyme assays confirmed that Est and MFO were related to abamectin resistance as metabolic factors. Moreover, some Est bands on a native isoelectric focusing gel were specifically inhibited by TPP, implying their association with resistance. Pretreatment with verapamil in synergistic bioassays did not reduce the LT50 to abamectin, suggesting that the ABC transporter is not likely involved in resistance. However, enhanced MFO and Est activities in the AbaR strain were not enough to account for the extremely high level of abamectin resistance, which suggests the involvement of additional resistance mechanisms, such as target site insensitivity.

병해충 관리를 위한 농약 판매업자 대상 처방 관련 설문조사 분석

권덕호,유기렬,이세진,김재수,안율균,홍규현,이영희 한국농약과학회 2023 농약과학회지 Vol.27 No.2

농약 판매업자를 대상으로 예방 및 진단 처방 관련 현황과 애로사항에 대한 설문조사를 2022년 04월부터2023년 03월까지 전국의 72개 농약 판매업체를 대상으로 수행하였다 . 우선 , 판매 현장에서 예방 및 진단적 처방 비율에 대한 질문에 응답자의 77%가 거의 1:1의 비율로 처방하여 , 판매상의 역할이 진단적 처방뿐만 아니라 예방적 처방도 활발하게 수행하고 있음을 알 수 있었다 . 예방적 처방을 수행하는 근거는 응답자의 81.9%가 과거의 경험을 기준으로 처방하며 , 진단적 처방의 경우에는 응답자의 65.3%가 작물확인 , 병해충 종동정 , 그리고 과거농약사용 확인후 처방을 하였다 . 진단적 처방 과정 중에 병해충 진단을 위한 해결책으로 주로 농촌진흥청 국가농작물병해충관리시스템 (61%)을 사용하였으며 , 주요 애로사항은 작용기작을 고려한 농약 추천 (61%)이였다 . 따라서 향후 판매업자 교육시 농약의 작용기작과 약효에 대한 이해를 돕는 교육이 필요한 것으로 판단된다 . 병해충 종동정 및 처방 전문가 양성방안에 대해서는 긍정과 부정이 첨예하게 대립하는 양상이였고 , 전문 교육 참여 필요성에 대해서는 62.5%로서 응답자의 과반이상이 참여가 필요하다고 응답하였다 . 본 연구 결과는 대학 , 국공립연구소 , 제조 회사에서 농약 판매업자의 진단 및 처방에 관한 인식과 처방 시 애로 사항에 대한 이해를 돕는데 기여할 것이다 .