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Evolutionary Explanation for Beauveria bassiana Being a Potent Biological Control Agent Against Agricultural Pests

  • Han, Jae-Gu
    • 한국균학회소식:학술대회논문집
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    • 2014.05a
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    • pp.27-28
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    • 2014
  • Beauveria bassiana (Cordycipitaceae, Hypocreales, Ascomycota) is an anamorphic fungus having a potential to be used as a biological control agent because it parasitizes a wide range of arthropod hosts including termites, aphids, beetles and many other insects. A number of bioactive secondary metabolites (SMs) have been isolated from B. bassiana and functionally verified. Among them, beauvericin and bassianolide are cyclic depsipeptides with antibiotic and insecticidal effects belonging to the enniatin family. Non-ribosomal peptide synthetases (NRPSs) play a crucial role in the synthesis of these secondary metabolites. NRPSs are modularly organized multienzyme complexes in which each module is responsible for the elongation of proteinogenic and non-protein amino acids, as well as carboxyl and hydroxyacids. A minimum of three domains are necessary for one NRPS elongation module: an adenylation (A) domain for substrate recognition and activation; a tholation (T) domain that tethers the growing peptide chain and the incoming aminoacyl unit; and a condensation (C) domain to catalyze peptide bond formation. Some of the optional domains include epimerization (E), heterocyclization (Cy) and oxidation (Ox) domains, which may modify the enzyme-bound precursors or intermediates. In the present study, we analyzed genomes of B. bassiana and its allied species in Hypocreales to verify the distribution of NRPS-encoding genes involving biosynthesis of beauvericin and bassianolide, and to unveil the evolutionary processes of the gene clusters. Initially, we retrieved completely or partially assembled genomic sequences of fungal species belonging to Hypocreales from public databases. SM biosynthesizing genes were predicted from the selected genomes using antiSMASH program. Adenylation (A) domains were extracted from the predicted NRPS, NRPS-like and NRPS-PKS hybrid genes, and used them to construct a phylogenetic tree. Based on the preliminary results of SM biosynthetic gene prediction in B. bassiana, we analyzed the conserved gene orders of beauvericin and bassianolide biosynthetic gene clusters among the hypocrealean fungi. Reciprocal best blast hit (RBH) approach was performed to identify the regions orthologous to the biosynthetic gene cluster in the selected fungal genomes. A clear recombination pattern was recognized in the inferred A-domain tree in which A-domains in the 1st and 2nd modules of beauvericin and bassianolide synthetases were grouped in CYCLO and EAS clades, respectively, suggesting that two modules of each synthetase have evolved independently. In addition, inferred topologies were congruent with the species phylogeny of Cordycipitaceae, indicating that the gene fusion event have occurred before the species divergence. Beauvericin and bassianolide synthetases turned out to possess identical domain organization as C-A-T-C-A-NM-T-T-C. We also predicted precursors of beauvericin and bassianolide synthetases based on the extracted signature residues in A-domain core motifs. The result showed that the A-domains in the 1st module of both synthetases select D-2-hydroxyisovalerate (D-Hiv), while A-domains in the 2nd modules specifically activate L-phenylalanine (Phe) in beauvericin synthetase and leucine (Leu) in bassianolide synthetase. antiSMASH ver. 2.0 predicted 15 genes in the beauvericin biosynthetic gene cluster of the B. bassiana genome dispersed across a total length of approximately 50kb. The beauvericin biosynthetic gene cluster contains beauvericin synthetase as well as kivr gene encoding NADPH-dependent ketoisovalerate reductase which is necessary to convert 2-ketoisovalarate to D-Hiv and a gene encoding a putative Gal4-like transcriptional regulator. Our syntenic comparison showed that species in Cordycipitaceae have almost conserved beauvericin biosynthetic gene cluster although the gene order and direction were sometimes variable. It is intriguing that there is no region orthologous to beauvericin synthetase gene in Cordyceps militaris genome. It is likely that beauvericin synthetase was present in common ancestor of Cordycipitaceae but selective gene loss has occurred in several species including C. militaris. Putative bassianolide biosynthetic gene cluster consisted of 16 genes including bassianolide synthetase, cytochrome P450 monooxygenase, and putative Gal4-like transcriptional regulator genes. Our synteny analysis found that only B. bassiana possessed a bassianolide synthetase gene among the studied fungi. This result is consistent with the groupings in A-domain tree in which bassianolide synthetase gene found in B. bassiana was not grouped with NRPS genes predicted in other species. We hypothesized that bassianolide biosynthesizing cluster genes in B. bassiana are possibly acquired by horizontal gene transfer (HGT) from distantly related fungi. The present study showed that B. bassiana is the only species capable of producing both beauvericin and bassianolide. This property led to B. bassiana infect multiple hosts and to be a potential biological control agent against agricultural pests.

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Breeding of a New Japanese Apricot (Prunus mume Siebold et Zucc.) Cultivar 'Okjoo' with High Yields (다수성 매실 품종 '옥주')

  • Kim, Yoon-Kyeong;Kang, Sam-Seok;Choi, Jang-Jeon;Cho, Kwang-Sik;Won, Kyeong-Ho;Lee, Han-Chan;Choi, Jin-Ho
    • Horticultural Science & Technology
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    • v.32 no.6
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    • pp.912-916
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    • 2014
  • Japanese apricot (Prunus mume Siebold and Zucc.) is a deciduous tree of the family Rosaceae, and it has long been used as a folk remedy for cough and dyspepsia. A new cultivar 'Okjoo' was developed from a cross between 'Gyokuei' and 'Rinsyu' carried out at the National Institute of Horticultural & Herbal Science in 1993. It w as s elected for good shape, large size and high yield capacity in 2006, and then it was granted official patent No. 4556 in 2013. It blooms 4 days and 2 days earlier than 'Gyokuei' and 'Rinsyu', respectively. Its flower petal color is pink, and the pollen amount is negligible. Its S-genotype, determined using Polymerase Chain Reaction with a S-RNase gene-specific primer pair, is $S_3S_6$. The average optimum harvest time of 'Okjoo' is late June. The fruit is round in shape and its suture is shallow. Average fruit weight is 18.5 g, and it contains total soluble solids $7.66^{\circ}Brix$ and titratable acidity at 4.81%. Fruit skin color is green. Sometimes only the light side of the fruits seems to develop blush. The incidence levels of scab (Cladosporium carpophilum Thumen) and bacterial shot hole (Xanthomonas arboricola pv. Pruni) are quite low. Consequently, 'Okjoo' seems to be a promising new cultivar for Japanese apricot growers.

Effect of Mother Trees and Dark Culture Condition Affecting on Somatic Embryogenesis of Liriodendron tulipifera L. (백합나무(Liriodendron tulipifera L.) 체세포배(體細胞胚) 발생(發生)에 미치는 모수(母樹) 및 암배양(暗培養) 효과(效果))

  • Son, Seog-Gu;Moon, Heung-Kyu;Kim, Yong-Wook;Kim, Ji-Ah
    • Journal of Korean Society of Forest Science
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    • v.94 no.1 s.158
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    • pp.39-44
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    • 2005
  • An effective micropropagation system for Liriodendron tulipifera L via somatic embryogenesis was established using immature seeds. Immature seeds from five individual trees were bisected longitudinally and cultured on two basal media (MS and B5) containing different combinations of 2,4-D and TDZ to induce callus and embryogenic tissue under light ($40{\mu}mol\;m^{-2}s^{-1}$, 16 hr/day) or complete darkness at $25{\pm}2^{\circ}C$. There was no distinctive difference on callus and embryogenic tissue induction between the two basal media with PGRs. Optimum culture medium appeared to be MS medium supplemented with 1.0mg/L 2,4-D and 0.01mg/L TDZ plus 3% sucrose. Nonembryogenic callus induction rate was not significantly different among the genotypes. However, However, the embryogenic callus induction frequency differed greatly by the genotypes ranging from 55% to 72% when cultured in the dark. Generally, the cultures maintained in the dark tended to show normal somatic embryo development as well as embryogenic tissue formation and this was confirmed by histological examination. Above results suggest that a proper selection of mother tree and dark culture condition are necessary to optimize somatic embryogenesis system of Liriodendron tulipifera.

Toxicity of various fruit tree extracts to five agricultural and four stored-product anthropod pests (다양한 과일나무에서 유래된 추출물의 농업해충 및 저장물해충에 대한 살충활성)

  • Lee, Sang-Guei;Park, Byeoung-Soo;Lee, Sung-Eun;Son, Jae-Gwon;Song, Cheol;Lee, Hoi-Seon
    • The Korean Journal of Pesticide Science
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    • v.5 no.4
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    • pp.27-32
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    • 2001
  • Methanol extracts from 43 materials of 17 fruit trees were tested for their insecticidal activities toward five agricultural and four stored-product anthropod pests. Efficacy varied with insect species, plant species, and tissue sampled. At a concentration of 2,500 ppm, strong activity was observed with extracts of Chaenomeles sinensis and Punica granatum seeds against Myzus persicae adult females, Vitis vinifera seeds against Nilaparvata lugens adults, Citrus junos, Citrus paradisi, Cucumis melo Linne var. reticulatus, Diospyros kaki, Malus pumila var. dulcissima, Prunug persica, and V. vinifera seeds against Plutella xylostella, Citrus sinensis seeds against Spedoptera litura larvae, and Ch. sinensis and V. vinifera against Tetranychus urticae adults. Against four stored-product insect pests at 50 ppm, seed extracts of Ch. sinensis and V. vinifera against Sitophilus oryzae adults, and Ch. sinensis, C. junos, D. kaki, and V. vinifera against Callosobruchus chinensis adults gave over 80% mortality. Extracts of all samples exhibited little and no activity against Lasioderma serricorne adults and Plodia interpunctella larvae.

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Management of Chestnut Insect Pests by Friendly Environmental Controls in Korea (친환경적 방법에 의한 밤 종실해충의 관리)

  • Lee, Chong-Kyu;Kim, Jong-Kab;Goo, Gawn-Hyo;Kang, Sung-Mee;Yun, Seok-Rak;Seo, Dong-Jin
    • Journal of Korean Society of Forest Science
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    • v.97 no.1
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    • pp.30-34
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    • 2008
  • This study was conducted to develop environmental techniques to reduce chestnut insect pests. The study sites were selected in intensive chestnut orchards of Jinju city, Gyeongnam province. In early and middleripening cultivars of chestnut tree, the damage of chestnut fruits by Dichocrocis punctiferalis was significantly lower in wromstop than other treatment such as Capture-machine, Nemacatch and Naphthalene (p<0.05), while there was no significant difference among treatments in late-ripening cultivars. The control effect of D. punctiferalis showed the highest in wormstop treanment with 90.68% and 80.58% in early and middle-ripening cultivars. The control effects for Curculio sikkimensis in late-ripening cultivars of chestnut tree was 80.58% in Nemacatch and 77.90% in Wormstop treatment.

Lateral Root Formation and Growth of Soybean Sporouts Treated with Various Solutions (다양한 물질처리에 의한 콩나물의 세근형성 및 생장)

  • Kang, Jin-Ho;Park, Cheol-Jong;Yoon, Soo-Young;Jeon, Seung-Ho;Hong, Dong-Oh
    • Korean Journal of Medicinal Crop Science
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    • v.13 no.1
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    • pp.6-10
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    • 2005
  • Lateral roots of soybean sprouts should deeply affect their quality and marketability. The study was done to compare the effects of ocher, chitosan, corn kennel, tea (Thea sinensis L.) and hard rubber tree (Eucommia ulmoides Oliver) leaf extracts on lateral root formation, growth and morphological characters of the sprouts. Seeds of three cultivars, Pungsannamulkong, Sowonkong and Junjery, were imbibed for 5 hours into their 10% solutions and cultured for 6 days. The cultured sprouts were classified into 4 categories to calculate their composition rates on the base of hypocotyl lengths;>7 cm (A), 4 to 7 cm (B), < 4 cm (C) and not germinated (D), and their morphological characters, fresh and dry weights were measured. Composition rate of A was the lowest in Junjery of the three cultivars, while that of C showed reverse result compared to A. This results was the most distinct in hard rubber tree leaf extracts (HRTLE) of the five treatments. In HRTLE treatment, lateral root formation rate were formed in almost of Sowonkong although reduced in order of Pungsannamulkong and Junjery. However, there was no significant difference between the other treatments. Lateral roots per sprout were the lowest in HRTLE treatment of the 5 treatments. In all treatments except the chitosan treatment, the roots were most formed in Sowonkong but least in Junjery. Sprout length adding hypocotyl and root was the shortest in Junjery compared to the other two cultivars. and was the longest in tea leaf extract treatment but the shortest in HRTLE treatment. The result in total fresh weight of sprouts was similar to that of the sprout length.

Ecological Studios on the Bark Beetles on Plum and Apricot (자두와 살구나무에 기생하는 나무좀의 생태에 관한 연구)

  • Yoon J. K.;Kim K. C.;Cheon S. J.;Kim Y. S.
    • Korean journal of applied entomology
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    • v.21 no.2 s.51
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    • pp.78-86
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    • 1982
  • The ecological studies were conducted to identify some bark-beetles on apricot and plum trees in Jeonnam province. Harmful bark-beetles caught from apricot and plum trees were identified as Scolytus seulensis. Xyleborus atratus., X. germanus, X. rubricollis and X. saxeseni. The seoul barkbeetle emerged during the period from early May to late October $1980\~1981$, it happens twice in a year, with the peak July 10 and August 25 in 1950, July 15 and August 20 in 1981. A daily peak emerged for adults was at 11 AM to 1 PM. Distribution of holes on the apricot stems varied; more than 100 holes per meter in Henderson (Apricot) and Y-49057 (Apricot), 12 holes per meter in Derbyroyal (Apricot). Comparatively more holes were found in the European variety, and the cardinal distribution was in the order of east, south, west and north. The longer the longth of the mother-gallery, the greater number of egg-gallery found. Optimum temperature for mating was $27^{\circ}C$. The time for mating was longer during May-June than July-August. The fruit weight of damaged plum tree reached 12.25g around four weeks after flowering; where as that of normal tree increased up to 63.5g at harvest time. The natural enemy of the seoul bark beetle was Eurytoma sp. They were found as mature larva or pupa and they emerged from early May to the middle of June. Adult longevity was about a week.

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Floristic Composition, Structure, and Dynamics of Koelreuteria paniculata Communities in Daegu City (대구시 자생 모감주나무군락의 종조성, 구조 및 동태)

  • Kim, Jun-Soo;Cho, Joon-Hee;Kim, Hak-Yun;Cho, Hyun-Je
    • Journal of Korean Society of Forest Science
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    • v.108 no.2
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    • pp.168-176
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    • 2019
  • To understand the floristic composition, vegetation structure, and population dynamics of Koelreuteria paniculata communities, which are native to Daegu, South Korea, a field survey was conducted in July 2018 using phytosociological and complete enumeration methods. Based on information on vegetation and trees of >5 cm diameter at breast height collected during the field survey, we classified the community types by species composition and analyzed their vegetation strata, relative importance value (MIV), life forms, species diversity, and population structure. The community was divided into the following three types: Ulmus parvifolia-Vitex negundo var. incisa subcommunity, Securinega suffruticosa subcommunity, and Clematis apiifolia community. The vegetation unit system was organized into one community group, two communities, and two subcommunities. Vegetation coverage of the tree layer was >85%, while the herbaceous layer was <10%. MIV of K. paniculata appeared to be extremely high within all vegetation strata, with 94.3 of the tree layer, 81.6 of the subtree layer, 75.5 of the shrub layer, and 60.0 of the herbaceous layer. The species diversity (H') was significantly different among the community types, and the C. apiifolia community (2.062) was approximately four times higher than the S. suffruticosa subcommunity (0.547). The overall representative life form types were "$MM-R_5-D_4{\cdot}D_2-e$,", but there were some differences in the disseminule form among the community types. The population structure of K. paniculata showed the reverse J-shaped distribution with a high density of young individuals and low density of larger individuals among all three community types, and because no plant species within the lower vegetation could replace K. paniculata, it was considered to be a sustainable population.

An Analysis of the Visual Preference on Parallax Space by Blockage Pattern and Ratio (차폐유형과 차폐도를 달리한 패럴랙스(Parallax) 공간의 시각 선호도)

  • Rho, Jae-Hyun
    • Journal of the Korean Institute of Landscape Architecture
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    • v.35 no.2 s.121
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    • pp.55-63
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    • 2007
  • The purpose of this study is to create a planting design for progressive realization. For this, visual preferences as measured via questionnaire were evaluated by the Scenic Beauty Estimation(SBE) and paired comparison methods. The results can be summarized as follows. Through photo observation, the average visual blockage ratio was 38% and the range of degree of the visual blockage ratio was $30{\sim}50%$. The sketch simulation and filtered pattern received the highest preference score and fumed out to be the most practical pattern out of all the patterns evaluated. Also, in the sketch simulation, the high preference values were observed for a distance of 9 to 12m from the view point to the blockage tree with a D/H ratio of 2. The preference score significantly decreased with the increase of the visual blockage ratio having a turning point at $30{\sim}35%$ of the visual blockage ratio, even though the distance parameters were more important than the visual blockage ratio in the scores. An outstanding view must be handled properly to be preserved or accentuated. Framed, open, enclosed, screened or filtered pattern views should be completely revealed only from their best vantage point, not given away at first glimpse. It this sense, parallax spatial beauty with trees could be improved through the visual aspects of plan arrangements and seems to be an effective design technique for landscape planning and planting design.

A study on dietary culture in Nara Dynasty in JAPAN (나양시대(奈良時代)의 식생활(食生活))

  • Lee, Hyo-Gee
    • Journal of the Korean Society of Food Culture
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    • v.12 no.1
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    • pp.11-16
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    • 1997
  • The Nara Dynasty of Japan lasted from 710 to 784 A.D, which corresponds to the period of the Unified Shilla Kingdom of Korea. The Nara Dynasty enacted the 'Daiho Law and Ordinance' by referring to those of Tang Dynasty of China. Under these legal systems, the Ministries were defined, and foods were used for paying taxes or as currency. The characteristics of the dietary culture in Nara Dynasty were as follows. 1) They obtained food from rice and other grain farming, hunting and fishery. Rice was their main staple and was also used for preparing porridge and brewing wine. 2) Under the influence of Buddhism, meat was prohibited, and milks or dairy products were supplemented for improving malnutritional status. 3) They also used seasonings, spices and sweeteners to enhance the taste and produced medicines by extracting plants, animals and minerals. 4) While chopsticks were made of bamboo, willow, silver, shell, tree or bronze, such utensils as pan earthenware steamer, or charcoal pots were used for preparing meals. 5) Highly qualified utensils, made of porcelains painted with lacguetr, metal, glass, horn and stone, were produced as handcraft art wad developed. 6) Chinese style cousines and cooking methods were popular and various types of preserving techniques like drying or salting were used. Processed cookies were also developed. 7) Although flour was used mainly among noble class people, ordinary people also used it. The royal families ate milk products a lot and even fried foods. 8) One can say that Buddism exerted an influence on Vegetarianism from this era.

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