The two-spotted spider mite, Tetranychus urticae Koch, is one of the most important agricultural pests. Therefore, we screened fifteen compounds from natural products for their spatial repellent and oviposition deterrent activities against T. urticae in the laboratory by using two-choice and no-choice tests. In the bridge two-choice test, nine compounds showed the spatial repellent effects on T. urticae at 20 mg dose, resulting in reduced numbers of eggs. Among the nine compounds, at 2 mg dose, two compounds were selected as having more spatial repellent activity than the others. The two compounds also showed spatial repellent and oviposition deterrent effects in the two-choice test from hosts. In the no-choice test from a host, the spatial repellent effects of the two compounds to T. urticae were significantly stronger than that of controls. These results suggest that the findings can be used as potential agents for the prevention and population control of T. urticae in the field.

The cotton aphid, Aphis gossypii glover (Hemiptera: Aphididae), is the world-wide agriculture pest and has the ability to become resistant to many pesticides. Hence, we conducted behavioral tests on apterous and alate aphids for series compounds from natural products by using a two-choice test, a no-choice test, a host choice test and electroantennography (EAG). As a result, we found 3 out of 30 compounds for apterous aphids and 2 out of 15 compounds for alate aphids, both of which showed powerful repellent effects on these aphids. In this study, we suggest that our findings could be useful and eco-friendly spatial repellents for controlling cotton aphid.

시설토마토에서 사전에 해충밀도를 예찰 하지 않고 작물 정식과 동시에 적용한, 기생성/포식성 천적과 그들의 먹이원/서식처가 결합되어 있는, ‘Natural Enemy in First (NEF)’ 기술의 총채벌레와 진딧물 방제효과를 확인하였다. 처리 후 12주차에 NEF 처리구에서 총채벌레 밀도억제 효과는 천적처리구 및 관행방제구에 비해 각각 32%와 82% 더 높았다. 처리 후 진딧물의 밀도는 모든 처리구에서 낮게 유지되어 처리구간 유의성 있는 차이를 확인할 수 없었다.

해충의 예찰 없이 작물 정식 초기에 천적을 먼저 적용할 수 있는 천적-서식처 혼합적용(Natural Enemy in First; NEF)기법의 방제효과를 확인하였다. 시설 딸기에서 조사 12주차에 NEF처리구와 천적 단독 처리구에서 친환경자재 처리구 대비 각 83%, 70%의 점박이응애 밀도 억제효과를 확인할 수 있었다. 또한 예찰 없이 작물 정식 초기에 NEF를 적용한 처리구에서 천적 단독 처리구보다 3배 이상의 높은 천적 밀도를 확인하였다.

Biological control is becoming an increasingly important part of integrated pest management programs in Korea. For this reason, effective and sustainable insect pest management is a priority for many growers. And the success of biological control depends upon the use of the economical methods such as a combination of proper natural enemies and plants (banker, habitat, trap, companion, etc.). For the last nine years, we have developed simple and reliable new habitat plants system with natural enemies, and named it『Natural Enemy in First Method』that we are introducing here. Our goal was to better understand the potential for effective use of beneficial insects and their habitat plants for the management of thrips, spider mites, and aphids in greenhouses. This approach is being developed to improve biological control in various crops in Korea.

Toll and IMD pathways play an important role in producing antimicrobial peptides (AMPs) through NF-κB in insects. The functions of IκB kinase (IKK) complex regulating the NF-κB signaling cascade have not yet been investigated in Tenebrio model. Here, we identified TmIKK-β (or TmIrd5) which contains 2,112 bp encoding 703 amino acid residues. Domain analysis shows that TmIKK-β contains one Serine/Threonine protein kinases catalytic domain. Developmental expression patterns indicate that TmIKK- β gene was highly expressed in early pupal (P1) and adult (A5) stages. Tissue specific profiles show that TmIKK-β was highly expressed in the integuments in last instar larvae, and fat body and hemocytes in 5 day-old adults. TmIKK-β1 transcripts were strongly induced at 3 and 12 h-post injection of E. coli, and 3 h-post injection of S. aureus or C. albicans in hemocytes. In gut, TmIKK-β transcripts were slightly induced by E. coli (at 6, 9 and 24 h) and C. albicans (at 24 h), while it was not induced by S. aureus challenge. Moreover, it was highly induced at 6 h-post injection of E. coli and then it was gradually decreased in the fat body. To understand the immunological role of TmIKK-β, gene specific RNAi and mortality assay was performed. Depletion of TmIKK-β mRNA leads to increase microbial susceptibility of larvae against E. coli, S. aureus and C. albicans. In addition, induction patterns of fourteen AMP genes in response to microbial challenge was tissue specifically investigated in TmIKK-β–silenced T. molitor larvae. The results suggest that expression of ten AMP genes out of fourteen genes were drastically decreased by TmIKK-β RNAi in fat body, suggesting that TmIKK-β plays an important role in antimicrobial innate immune responses.

It has been well known that IKK-β, -ε and –γ play a pivotal role in IMD pathway. In this study, TmIKK-ε was identified and their functions in countering pathogenic infections were investigated. We identified TmIKK-ε gene which including 2,196 bp nucleotides (encoding 731 amino acid residues). Domain analysis of TmIKK-ε indicates that there is one Serine/Threonine protein kinases catalytic domain. TmIKK-ε gene was highly expressed in 2 day-old pupal stage and the expression was gradually decreased until 1 day-old adults. Then the expression was slightly increased until 4 day-old adult stage. Tissue specific expression of TmIKK-ε mRNA was high in the gut, integuments and hemocytes in last instar larvae, and fat body, Malpighian tubules and testis in 5-daysold adult. In hemocytes, TmIKK-ε was drastically induced by E. coli injection after 3 h and by S. aureus at 3 and 12 h-post injection. In gut, expression level of TmIKK-ε was high at 6 h-post injection of microbial injection. Expression of TmIKK-ε in fat body was drastically induced by E. coli at 3 and 24 h-post injection while it was not significantly induced by S. aureus and C. albicans. To understand the immunological role of TmIKK-ε, gene specific RNAi and mortality assay were performed. TmIKK-ε RNAi caused increased larval mortality against E. coli, not S. aureus and C. albicans. Finally, to investigate the induction patterns of Tenebrio fourteen AMP genes in response TmIKK-ε RNAi, three microorganisms were treated into TmIKK-ε-silenced T. molitor larvae. Nine out of fourteen AMP genes were not induced by microbial challenge in TmIKK-β dsRNA-injected group. Taken together, our results indicate that TmIKK-ε may regulates nine antimicrobial peptide genes in response to microbial challenge in T. molitor fat body.

본 연구는 지속가능한 유기농업의 실천을 위하여 국내 작부체계와 농업환경에 적합한 한국형 현장적용 기법을 구축하고자 수행하였다. 본 연구의 기본 개념은 ‘Natural Enemy in First (NE가 먼저)’로 해충발생시기의 예찰 없이 주 작물을 정식함과 동시에 천적과 보조식물을 혼합 적용해서 해충발생 이전에 천적을 포장에 먼저 정착시키는 생물적 방제기법이다. 시설재배 딸기에서 칠레이리응애, 사막이리응애, 콜레마니진디벌과 천적의 서식처 3종을 주 작물의 정식과 동시에 적용한 결과, 관행방제구에 비해 80%이상의 해충 밀도억제효과를, 천적 단독처리구에 비해 3배 이상의 높은 천적의 밀도를 확인할 수 있었다. 또한 포장 환경과 천적의 방사방법에 구애받지 않고 천적의 해충 방제효과를 극대화시킬 수 있는 라인을 적용한 결과, 약제와 천적 혼합처리구에서 라인을 적용하지 않은 처리구에 비해 해충의 밀도가 급격히 감소하고, 천적의 밀도는 2배 이상 높게 유지되는 것을 확인할 수 있었다.

IKK-γ is an essential protein to form IKK complex which regulate NF-κB. We identified TmIKK-γ (or TmKenny) gene which has 1,521 bp of nucleotides encoding 506 amino acid residues. Domain analysis of TmIKK-γ shows that there are one NF-κB essential modulator (NEMO) domain and a leucine zipper domain. Expression of TmIKK-γ gene was gradually increased from egg to 2-day-old pupal stage, dramatically decreased until 7 day-old pupal stage, and then it was gradually increased. TmIKK-γ transcripts were highly expressed in fat body and hemocytes in late instar larvae and integuments, fat body and Malpighian tubules in 5 day-old adult. TmIKK-γ was drastically induced by E. coli after 3 h challenges and by S. aureus at 3 and 12 h-post injection in hemocytes. TmIKK-γ was not induced by C. albicans although it was significantly induced by E. coli (at 3, 6 and 24 h) and S. aureus (at 9 h) in gut. In fat body, expression of TmIKK-γ was drastically induced by E. coli at 3 and 24 h-post injection while it was not significantly induced by S. aureus and C. albicans. To understand the immunological role of TmIKK-γ, gene specific RNAi and mortality assay was performed. larval mortality against microbial challenge was dramatically increased by TmIKK-γ RNAi. Furthermore, we investigate the tissue specific induction patterns of fourteen AMP genes in response TmIKK-γ dsRNA-treatment. In fat body, ten AMP genes out of fourteen was not significantly induced by microbial challenge in TmIKK-γ dsRNA-treated group. Based on these results, TmIKK-γ might play an important role in antimicrobial innate immune responses in Tenebrio molitor.

The beneficial effect of silicon (Si) in increasing salt stress tolerance has been observed in many plants, including the cereal crops rice, wheat, and barley. In this experiment, we examined the effect of Si on the survival and growth of torenia (Torenia fournieri L inden ex F oum) ‘ Duchess Blue and White’ cultured in vitro in the presence and absence of salt stress. Previous reports had suggested that torenia exhibited low salt tolerance. Shoot buds isolated from 16-day-old seedlings were cultured on Murashige and Skoog (MS) medium containing 0, 50, or 100 mM NaCl alone or in combination with 1.8 or 3.6 mM Si supplied as K2SiO3. Plant survival rate was significantly reduced by NaCl supplementation compared with the control. The survival rate significantly increased to 100% when 1.8 or 3.6 mM Si was added to the MS medium containing 50 mM NaCl. However, only 31% of plantlets survived when 1.8 mM Si was added to the culture medium containing 100 mM NaCl. Shoot and root lengths significantly decreased with increasing NaCl concentration in the culture medium, whereas addition of NaCl to the MS medium also significantly reduced fresh and dry weights. However, Si supplementation significantly increased fresh and dry weights under 50 mM NaCl, compared with the control. The greatest fresh and dry weights were recorded when shoot buds were cultured on MS medium containing 50 mM NaCl and 3.6 mM Si. The activities of the antioxidant-scavenging enzymes superoxide dismutase (SOD), ascorbate peroxidase (APX), and catalase (CAT), but not peroxidase (POD), were markedly higher in the presence of 50 mM NaCl than the activity of the control. When Si was added to the medium containing 50 mM NaCl, activities of SOD, POD, APX, and CAT decreased as compared with the 50 mM NaCl treatment. Thus, Si-mediated tolerance to NaCl stress was not due to increased activity of antioxidant enzymes. Although Si was not effective in increasing tolerance to high salt concentrations, such as 100 mM NaCl, the results suggested that Si supplementation could effectively enhance tolerance to 50 mM NaCl stress.

The aim of this study is to investigate the antioxidant and intracellular anti-inflammatory efficacy of blueberry leaf extracted with hot water (BLW), 70% ethanol (BLE), and 70% acetone (BLA) in RAW 264.7 macrophages. In order to evaluate the anti-inflammatory effect of blueberry leaf extracts, RAW 264.7 macrophages were stimulated with lipopolysaccharide (LPS) to induce the production of inflammation-related factors, which were measure by Western blotting and real-time PCR methods. i-NOS, COX-2 protein, and mRNA expression showed concentration-dependent decrease. The decreases in the mRNA expression levels of interleukin-1β (IL-1β), interleukin-6 (IL-6), tumor necrosis factor-α (TNF-α), and prostaglandin E2 (PGE2) were concentration-dependent. Further, the antioxidant effects of blueberry leaf on total polyphenol contents, electron donating ability and ABTS+ radical scavenging activity were evaluated. The total polyphenol contents of BLW, BLE, and BLA were 217.04±2.98, 156.72±3.90, and 182.88±3.02 mg TAE/g, respectively, while the electron donating abilities at 1,000 μg/mL of BLW, BLE, and BLA were 81.7, 79.6, and 79.3%, respectively. The ABTS+ radical scavenging activity was fond to be concentration dependent. The nitric oxide (NO) production inhibition activities at 50 μg/mL of BLW, BLE, and BLA were 35.1, 42.4 and 42.7%, respectively. In conclusion, the antioxidant and anti-inflammatory test results indicate that blueberry leaf extracts (BLW, BLE, and BLA) can be used as potential anti-inflammatory agents.