Metarhizium은 대표적인 곤충병원성 진균 중 하나로, 종에 따라 매우 다양한 곤충에게 병원성을 일으키는 폭 넓은 기주범위를 형성한다. 이들이 주로 생성하는 것으로 알려진 destruxins (DTXs)이라는 2차 대사산물은 살충 활성 뿐만 아니라 항바이러스, 항증식, 항암 등 다양한 분야에서 효능이 연구되고 있어, 해당 물질에 대한 관심이 집중되고 있다. 살충 물질로서의 DTXs는 여러 곤충에 있어 병원성을 나타내는 것이 확인되었으나, 해충 으로서 전 세계적으로 심각한 경제적 피해를 일으킴과 동시에, 화학 살충제 저항성 문제가 야기되고 있는 목화진 딧물에 대해서는 아직 DTXs의 역할이 연구되지 않고 있는 실정이다. 본 연구에서는 목화진딧물에 대해 곤충병원 성 진균 Metarhizium spp.의 병원성 발현에 DTXs가 미치는 역할을 간접적으로 확인하기 위해, qPCR을 활용하여 진균 처리 후 목화진딧물 사망 시간과 관련하여 충체 내 DTX 합성효소의 발현을 비교 분석하였다.

Mycoviruses are a group of viruses that infect filamentous fungi. While most hosts infected with mycoviruses do not show any symptoms. In some cases, mycoviruses induce various phenotypic changes include alterations in morphology, drug resistance, pathogenicity, virulence, sporulation, and growth. Entomopathogenic fungi are one of the integrated pest management agents as an alternative to conventional insecticides. Mycoviruses have the potential as supportive agents, enhancing the efficiency of the insecticidal activity of the fungi. Studies about mycoviruses themselves and their interaction with their hosts, especially entomopathogenic fungi, are needed to realize their full potential. In this work, the sequence of the dsRNA element isolated from the entomopathogenic fungus Metarhizium pinghaense 4-2 strain was determined. Through this study, we report the sequence of a dsRNA virus isolated from the Metarhizium pinghaense for the first time. In further studies, the ORF of the mycovirus that induces a phenotype change in the host will be researched.

Aphis gossypii is a representative pest that transmits plant viral diseases. It is difficult to control with chemical pesticides alone due to their high pesticide resistance. Entomopathogenic fungi are biological control agents that can replace chemical pesticides and have characteristics of high host specificity and safety to humans. Therefore, we investigated the immune pathways of aphids against initial infection by entomopathogenic fungus. We treated aphids with the Beauveria bassiana JEF 544 strain and examined the immune response in early infection by qPCR. furthermore, we also studied changes the molting time of nymphs and changes in adult nymphal production caused by entomopathogenic fungi.

마이코바이러스는 곰팡이를 감염시키는 바이러스로 자낭균류, 담자균류 및 난균류에서 주로 발견되며 일부 의 경우 곰팡이의 표현형에 영향을 끼치는 것으로 알려져 있다. 이번 연구에서는 대한민국 토양 샘플에서 분리된 65개의 자낭균류 및 접합균류 균주의 전체 핵산을 추출하고, 전기영동을 통해 바이러스 특이적 밴드를 스크리닝 하였다. 스크리닝 결과 65개의 균주 중에서 Tolypocladium spp. 균주 2개와 Marquandomyces marquandii 균주 1개에서 바이러스 특이적 밴드를 발견하였다. 그 후, Cellulose Chromatography를 이용하여 double-stranded RNA 를 분리하고 DNase I 및 S1 Nuclease 처리를 통해 DNA와 single-stranded RNA를 제거하여, Tolypocladium sp. 균주 1개와 Marquandomyces marquandii 균주에서 발견한 특이적 밴드가 dsRNA임을 확인하였다. 추후 virus-free isogenic line을 확보하여 virus 유무에 따른 표현형 변화를 확인하고, 마이코바이러스와 곰팡이 간의 상호작용에 관해 연구할 계획이다.

Aphids are well-known insect pests that, due to their feeding habits, affect various crops' productivity and marketability. Additionally, they cause significant damage worldwide as vectors of viruses. Chemical pesticides are widely used to control these agricultural pests. However, due to resistance to various chemical pesticides, pest control is becoming difficult in agricultural environments. Entomopathogenic fungi such as the genus Metarhizium and Beauveria are being extensively researched as alternatives to these chemical pesticides. In this study, the mycological properties of isolated from soil Metarhizium pemphigi IPBL-H and the insecticidal activity of this strain against Myzus persicae and Aphis gossypii were evaluated for potential of development as a biopesticide.

Cryptotympana atrata belongs to the family Cicadidae, has long been recognized as a damaging plant-sucking pest, and is distributed in East Asian countries. In addition, their cries cause direct harm to us through noise pollution and also reported twig damage in the forest environments. In this study, we isolated strains of the entomopathogenic fungus Metarhizium that occurred from C. atrata collected this year. Here, we provide the morphological character and molecular phylogenetic relationship of this species. This is the first record of the entomopathogenic fungus Metarhizium viridulum isolated from C. atrata in Korea and provides a candidate strain with potential use for biological agents.

This study was aimed to isolate bacterial inoculants producing chitinase and evaluate their application effects on corn silage. Four corn silages were collected from four beef cattle farms to serve as the sources of bacterial inoculants. All isolates were tested against Fusarium graminearum head blight fungus MHGNU F132 to confirm their antifungal effects. The enzyme activities (carboxylesterase and chitinase) were also measured to isolate the bacterial inoculant. Based on the activities of anti-head blight fungus, carboxylesterase, and chitinase, L. buchneri L11-1 and L. paracasei L9-3 were subjected to silage production. Corn forage (cv. Gwangpyeongok) was ensiled into a 10 L mini silo (5 kg) in quadruplication for 90 days. A 2 × 2 factorial design consists of F. graminearum contamination at 1.0104 cfu/g (UCT (no contamination) vs. CT (contamination)) and inoculant application at 2.1 × 105 cfu/g (CON (no inoculant) vs. INO (inoculant)) used in this study. After 90 days of ensiling, the contents of CP, NDF, and ADF increased (p<0.05) by F. graminearum contamination, while IVDMD, acetate, and aerobic stability decreased (p<0.05). Meanwhile, aerobic stability decreased (p<0.05) by inoculant application. There were interaction effects (p<0.05) on IVNDFD, NH3-N, LAB, and yeast, which were highest in UCT-INO, UCT-CON, CT-INO, and CT-CON & INO, respectively. In conclusion, this study found that mold contamination could negatively impact silage quality, but isolated inoculants had limited effects on IVNDFD and yeast.

Aging are both global and domestic issues. In Korea, the population aged 65 and over accounted for 14.8% of the total population in 2018 and 14.4% in Jeju island. The Korea National Statistical Office estimates it will reach 41% by 2060. As the elderly population increases, socioeconomic policy changes and researches on health aging have been carried out especially in developed countries. Representative studies are telomere studies and molecular inflammation. Korean researchers also have made efforts to elucidate the secret of aging including TLR5 (Toll-like receptor 5)/caveolin study in Jeolla province, and ROS (reactive oxygen species) and molecular inflammation in Gyungsang province. However, Research on aging is still underway and research on gut microbiota started in Jeju province, centering on progeria, is expected to give hope.

현재 농가에서 이용되고 있는 보광등과 난방등의 특성을 조사하고 하우스내 기상 환경과 절화장미의 개화와 품질에 미치는 영향을 알아보기 위해 실험을 수행하였다. 보광등으로는 LED등(light emitting diode lamp, LED), 메탈할라이드등(metal halide lamp, MH), 고압나트륨등(high pressure sodium lamp, HPS)을, 난방등으로는 나노탄소섬유 적외선등(nano-carbon fiber infrared lamp, NCFI)을 절화장미 재배상 위에 설치하였다. 그 결과 LED와 NCFI의 광도는 각각 6.8μmol·m-2·s-1과 0.4μmol·m-2·s-1으로 매우 낮은 반면, MH와 HPS는 79 ~ 100μmol·m-2·s-1 범위로 높은 편이었다. 또한 LED와 MH는 적외선역에 파장이 없어 발열량이 거의 없었으나, HPS와 NCFI는 적외선역에 파장이 많아 발열이 많은 것으로 나타났다. 동일한 공간에서 칸막이로 실험구간을 나누어 실험이 수행되었음에도 불구하고 MH, HPS, NCFI에 의해 온도는 2°C 정도 상승되는 결과를 얻었으나, 습도에서는 처리간 차이가 보이지 않았다. 광도에 상관없이 모든 전등들은 절화장미의 개화를 촉진시켜 무처리구에 비해 적게는 5 ~ 7일, 많게는 12 ~ 14일 개화가 촉진되는 것으로 나타났다. 광량이 충분한 봄철에는 전조처리에 의해 개화소요일수가 짧아지는 만큼 절화장도 대조구보다 짧아졌지만, 광량이 부족한 겨울철에는 전조처리에 의해 절화장이 길어져 품질이 향상되는 결과를 얻을 수 있었다.