• Title/Summary/Keyword: 저항성 기작

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집중조명 - 제초제 저항성 잡초 및 관리방안

  • Park, Gi-Ung
    • Life and Agrochemicals
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    • s.262
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    • pp.18-21
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    • 2010
  • 저항성 잡초의 발생 및 조기 확산을 방지하기 위한 재배방법이나 제초제 사용요령 등의 지속적으로 교육 홍보가 필요하며, 모니터링과 저항성 발현기작 연구 등을 통해 올바른 진단이 이루어질 수 있도록 정부는 조속히 대책을 수립해야 한다.

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Resistance Mechanisms of Green Peach Aphid, Myzus persicae (Homoptera: Aphididae), to Imidacloprid (복숭아혹진딧물(Myzus persicae)의 imidacloprid에 대한 저항성 기작)

  • 최병렬;이시우;유재기
    • Korean journal of applied entomology
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    • v.40 no.3
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    • pp.265-271
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    • 2001
  • Resistance mechanisms in the green peach aphid (Myzus persicae) resistant to imidacloprid were investigated. Imidacloprid residues on the aphid integuments decreased slowly as time passed with no significant difference between the susceptible and resistant strains. Residue in the aphid body increased in both strains with time elapse, and was slightly more in the susceptible strain. A higher metabolic rate of imidacloprid in the resistant strain can be expected by the fact that more amount of imidacloprid were excreted in the resistant strain than in the susceptible one. The activity of AChE was higher 1.4 times in the resistant strain than in the susceptible one, and imidacloprid did not inhibit AChE at all in both strains. Piperonyl butoxide (PBO) and iprobenfos (IBP) synergized imidacloprid activity. The mixtures of imidacloprid and PBO (1 : 1 and 1 : 5) caused 69.4- and 250-fold increase of imidacloprid toxicity against the aphid. Insecticide toxicity of the mixtures of IBP and imidacloprid (1 : 1 and 1 : 5) was also increased 227 and 80.6 times. Esterase activity when $\alpha$-naphtyl butyrate and $\beta$-naphtyl acetate were used as substrates was higher in the resistance strain than in the susceptible one. This means that P450 monooxygenase and esterase are responsible for the resistance to imidacloprid in this aphid strain.

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Cross-resistance of Colletotrichum acutatum s. lat. to Strobilurin Fungicides and Inhibitory Effect of Fungicides with Other Mechanisms on C. acutatum s. lat. Resistant to Pyraclostrobin (Strobilurin계 살균제에 대한 고추탄저병균의 교차저항성과 Pyraclostrobin 저항성균에 대한 다른 기작 살균제의 억제 효과)

  • Park, Subin;Kim, Heung Tae
    • Research in Plant Disease
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    • v.28 no.3
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    • pp.122-131
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    • 2022
  • Colletotrichum acutatum s. lat. 20JDS8 sensitive and 20CDJ6 resistant to pylaclostrobin were used to investigate the cross-resistance with fungicides belonging to the strobilurins and the characteristics of fungicidal controlling activities with different mechanisms against the isolate resistant to the fungicide. The resistant isolate of 20CDJ6 also showed the resistance to azoxystrobin, trifloxystrobin, and kresoxim-methyl, suggesting that there is a cross-resistance relationship. All fungicides with different action mechanisms inhibited mycelial growth of both susceptible and resistant isolates of C. acutatum s. lat., but their disease control effects in fruits were different according to the fungicides. The disease control effect of isopyrazam against 20JDS8 and 20CDJ6 was very low, and fluazinam showed a control effect of 91.9% and 88.1% against 20JDS8 and 20CDJ6 only when it was treated before inoculation by spraying spore suspensions on pepper fruits without wounds. Tebuconazole and prochloraz effectively inhibited not only the mycelial growth of 20JDS8 and 20CDJ6 on potato dextrose agar medium, but also disease incidence in red pepper fruits. As a result of this study, C. acutatum s. lat. 20CDJ6 resistant to pyraclostrobin showed cross-resistance with other strobilurin fungicides. In addition, we think that fluazinam, tebuconazole, and prochloraz can be recommended as alternative fungicides for the control of red-pepper pyranthracnose pathogens resistant pyraclostrobin. However, fluazinam can be effective only if it is treated protectively before the occurrence of the disease.

Role of general esterases in deltamethrin resistance mechanism of diamondback moth, Plutrlla xylostella L. (배추좀나방(Pulltella xylostella L.)의 deltamethrin 저항성 기작에 관한 에스테라제의 역할)

  • 김용균;장동걸
    • Korean journal of applied entomology
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    • v.35 no.1
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    • pp.74-79
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    • 1996
  • General esterases were analysed quantitatively and qualitatively to see their role in deltamethrin resistance mechanisms of the diamondback moth, Plutella xylostella L. Selection with 0.1 g of deltamethrin in each generation induced the moth to decrease susceptibility to the insecticide and to increase esterase activities of the fourth instar larvae. Both characters were highly correlated so that the correlation coefficient (r) between LDSo @g) of deltamethrin and esterase activities (~M/min/pg) was 0.9918 (P=0.0082). Nondenaturing PAGE (6%) separated 17 esterase bands from the whole body extracts of the fourth instar larvae. Deltamethrin-selected populations had fewer esterase bands than had the unselected. Four esterase bands (E3, E4, Ell, and E13) were, however, specific to deltamethrin-selected populations.

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Varietal Resistance of Rice to the Green Rice Leafhopper, Nephotettix cincticeps Uhler (끝동매미충에 대한 벼의 저항성 및 그 기작에 관한 연구)

  • Choi Seung Yoon
    • Korean journal of applied entomology
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    • v.14 no.1 s.22
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    • pp.13-21
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    • 1975
  • Experiments were conducted to select the new varieties and or/lines of rice resistant to the green rice leafhopper, Nephotettix cincticeps Uhler, and to evaluate the nature of their resistance to the insects in connection with the antibiosis and feeding and ovipositional preferences. The materials tested in this study were the varieties and or/lines of rice mostly proposed by the International Insect Resistance Nursery of IRRI and some others also orginiated from IRRI. Out of the 48 varieties and or/lines the 9 were selected as resistant and the 11 as mderately resistant. They have high antibiosis to the insects, showing significantly higher nymphal mortality and less adult emergence in the resistant and moderately resistant ones than the susceptible and moderately susceptible varieties Jinheung and Tong-il. Feeding perference was significantly different between the resistant and susceptible rice plants, resulting in much lower on resistant ones and much higher on susceptible ones. Ovipositional preference, however, was not different at all between the resistant and the susceptible ones. The nature of varietal resistance of rice to the green rice leafhopper seemed to be surely associated with the antibiosis and non-feeding preference.

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The Roles of Protein Degradation During Fungal-plant Interactions (단백질 분해가 식물의 진균 병 진전에 미치는 영향)

  • Ahn, Il-Pyung;Park, Sang-Ryeol;Bae, Shin-Chul
    • The Korean Journal of Mycology
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    • v.38 no.2
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    • pp.89-94
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    • 2010
  • Plant pathogenic fungi are the most diverse and drastic causal agents of crop diseases threatening stable food production all over the world. Plant have evolved efficient innate immune system to scout and counterattack fungal invasion and pathogenic fungi also developed virulence system to nullify plant resistance machinery or signaling pathways and to propagate and dominate within their niche. A growing body of evidences suggests that post translational modifications (PTMs) and selective/nonselective degradations of proteins involved in virulence expression of plant pathogenic fungi and plant defense machinery should play pivotal roles during the compatible and incompatible interactions. This review elucidates recent investigations about the effects of PTMs and protein degradations on host defense and fungal pathogens' invasions.

Insecticide Resistance Mechanism in the Spiraea Aphid, Aphis citricola (van der Goot) (조팝나무진딧물의 살충제 저항성 메카니즘에 관한 연구)

  • ;;本山直樹
    • Korean journal of applied entomology
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    • v.34 no.2
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    • pp.89-94
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    • 1995
  • Resistance mechanism of organophosphorus insecticides (OPs) in the spiraea aphid, whose populations were originated from several apple orchards where various OPs were frequently sprayed, was investigated. For Wonju population to which insecticides were not sprayed, resistance ratios (BRs) for pirimicarb, phosphamidon, and demeton S-methyl re 49, 31, and 5, respectively. However, for Yesan population to which OPs were sprayed 5 times, RRs for pirimicarb, phosphamidn, and dementon were 830, 536, and 204, respectively. The esterase activities of Wonju and Yesean populations increased by 44.5 and 92.0% compare to that of Kwagju population. R/S a values (S clone Kwangju population; R clone: Iechon opulation) for acetylcholinesterase (AChE) inhibition (${I}_{50}$) by pirimicarb and phosphamidon were 299.2 and 186.0, respectively. Our results indicate that increase of esterase activity and reduction of AChE sensitivity seemed to contribute insecticide resistance of the spiraea aphid.

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Resistance of Diamondback Moth(Plutella xylostella L.: Yponomeutidae: Lepidoptera) against Bacillus thuringiensis Berliner (BT제에 대한 배추좀나방의 약제저항성)

  • 송승석
    • Korean journal of applied entomology
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    • v.30 no.4
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    • pp.291-293
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    • 1991
  • Inter-regional difference in median lethal concentration of Bacillus thuringiensis diamondback moth was disclosed to be high. Pyungchang strain showed at most 41 times resistance compared to KN-IA strain of which $LC_{50}$ value was 5.5 ppm. and Oksan strain Showed 11 times resistance. The JMC strain, susceptible to pyrethroids, also showed 12 times resistance against B.T., suggesting difference in resistance mechanism between pyrethroid and B.t.

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Evolution of Plant RNA Viruses and Mechanisms in Overcoming Plant Resistance (식물 RNA 바이러스의 진화와 병저항성 극복 기작)

  • Kim, Myung-Hwi;Kwon, Sun-Jung;Seo, Jang-Kyun
    • Research in Plant Disease
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    • v.27 no.4
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    • pp.137-148
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    • 2021
  • Plant RNA viruses are one of the most destructive pathogens that cause a significant loss in crop production worldwide. They have evolved with high genetic diversity and adaptability due to the short replication cycle and high mutation rate during genome replication, which are characteristics of RNA viruses. Plant RNA viruses exist as quasispecies with high genetic diversity; thereby, a rapid population transition with new fitness can occur due to selective pressure resulting from environmental changes. Plant resistance can act as selective pressure and affect the fitness of the virus, which may lead to the emergence of resistance-breaking variants. In this paper, we introduced the evolutionary perspectives of plant RNA viruses and the driving forces in their evolution. Based on this, we discussed the mechanism of the emergence of variant viruses that overcome plant resistance. In addition, strategies for deploying plant resistance to viral diseases and improving resistance durability were discussed.