• Journal of Plant Biology
• /
• v.37 no.3
• /
• pp.309-316
• /
• 1994

To make regional comparisons of water status of pitch pine, the temporal changes of water status in pitch pine were investigated at different areas; urban Seoul (heavily polluted area), surburb of Seoul (lightly polluted area), and rural area (control). The effects of air pollutants, acid rain and chemical properties of soil on water deficit in pitch pine were also investiaged. Water content of needles growing at polluted areas were usually lower than that at unpolluted area. Water saturation deficit of needles growing at polluted areas were usually higher than that at unpolluted area especially in dry season. These results indicated that water in needles growing at polluted areas were usually more deficient than that at unpolluted area, and were more deficient in April than other months. At polluted areas, the older the needles were, the more quickly transpirated the water in the needle was. At unpolluted areas, however, water in old needles was not so quickly transpirated as those at polluted areas. Water potential of needles of pitch pine seedlings treated with simulated acid rain (SAR) of pH 3.5 decreased more quickly than that of needles treated with SAR of pH 5.6. Loss of water through epicuticular layer was greater in the following order: magnesium deficiency＋100 $\mu$M aluminium>100$\mu$M aluminium>magnesium deficiency>control. In addition to Mg deficiency and Al toxicity, growth decline of pitch pine widely occurring in polluated Seoul could to a large extent be due to cuticle degredation and abnormal vertical distribution of fine roots, which lead to water stress, particularly in dry seasons.

• Journal of Microbiology and Biotechnology
• /
• v.24 no.11
• /
• pp.1495-1502
• /
• 2014

Metarhizium anisopliae is a widely studied model to understand the virulence factors that participate in pathogenicity. Proteases such as subtilisin-like enzymes (Pr1) and trypsin-like enzymes (Pr2) are considered important factors for insect cuticle degradation. In four M. anisopliae strains (798, 6342, 6345, and 6347), the presence of pr1 and pr2 genes, as well as the enzymatic activity of these genes, was correlated with their virulence against two different insect pests. The 11 pr1 genes (A, B, C, D, E, F, G, H, I, J, and K) and pr2 gene were found in all strains. The activity of individual Pr1 and Pr2 proteases exhibited variation in time (24, 48, 72, and 96 h) and in the presence or absence of chitin as the inductor. The highest Pr1 enzymatic activity was shown by strain 798 at 48 h with chitin. The highest Pr2 enzymatic activity was exhibited by the 6342 and 6347 strains, both grown with chitin at 24 and 48 h, respectively. Highest mortality on S. exigua was caused by strain 6342 at 48 h, and strains 6342, 6345, and 6347 caused the highest mortality 7 days later. Mortality on Prosapia reached 30% without variation. The presence of subtilisin and trypsin genes and the activity of these proteases in M. anisopliae strains cannot be associated with the virulence against the two insect pests. Probably, subtilisin and trypsin enzyme production is not a vital factor for pathogenicity, but its contribution is important to the pathogenicity process.

• Journal of Microbiology and Biotechnology
• /
• v.24 no.1
• /
• pp.1-7
• /
• 2014

The possibility of using hyphomycete fungi as suitable biocontrol agents against greenhouse whitefly has led to the isolation of various insect pathogenic fungi. Among them is Beauveria bassiana, one of the most studied entomopathogenic fungi. The objective of this study was to use B. bassiana M130 as an insecticidal agent against the greenhouse whitefly. M130 isolated from infected insects is known to be a biocontrol agent against greenhouse whitefly. Phylogenetic classification of M130 was determined according to its morphological features and 18S rRNA sequence analysis. M130 was identified as B. bassiana M130 and showed chitinase (342.28 units/ml) and protease (461.70 units/ml) activities, which were involved in the invasion of the host through the outer cuticle layer, thus killing them. The insecticidal activity was 55.2% in petri-dish test, 84.6% in pot test, and 45.3% in field test. The results of this study indicate that B. bassiana has potential as a biological agent for the control of greenhouse whitefly to replace chemical pesticides.

• Journal of Ginseng Research
• /
• v.41 no.4
• /
• pp.463-468
• /
• 2017

Background: Both Panax ginseng Meyer and Panax quinquefolius are obligate shade-loving plants whose natural habitats are broadleaved forests of Eastern Asia and North America. Panax species are easily damaged by photoinhibition when they are exposed to high temperatures or insufficient shade. In this study, a cytohistological study of the leaf structures of two of the most well-known Panax species was performed to better understand the physiological processes that limit photosynthesis. Methods: Leaves of ginseng plants grown in soil and hydroponic culture were sectioned for analysis. Leaf structures of both Panax species were observed using a light microscope, scanning electron microscope, and transmission electron microscope. Results: The mesostructure of both P. ginseng and P. quinquefolius frequently had one layer of non-cylindrical palisade cells and three or four layers of spongy parenchymal cells. P. quinquefolius contained a similar number of stomata in the abaxial leaf surface but more tightly appressed enlarged grana stacks than P. ginseng contained. The adaxial surface of the epidermis in P. quinquefolius showed cuticle ridges with a pattern similar to that of P. ginseng. Conclusion: The anatomical leaf structure of both P. ginseng and P. quinquefolius shows that they are typical shade-loving sciophytes. Slight differences in chloroplast structure suggests that the two different species can be authenticated using transmission electron microscopy images, and light-resistant cultivar breeding can be performed via controlling photosynthesis efficiency.

• Journal of Digital Convergence
• /
• v.18 no.8
• /
• pp.479-484
• /
• 2020

In the social atmosphere where the importance of appearance is increasing day by day, efforts and desires of modern people are becoming more active and diversified, and the beauty beauty industry is gradually becoming more specialized and specialized due to these effects. Hair damage is inevitable due to the excessive permanent wave or hair coloring of modern people. However, as the hair is damaged, the cuticle peels off and falls off, and the tensile force decreases and the satisfaction after hair styling or perm decreases relatively. Therefore, it is necessary to manage damaged hair, but since artificial synthetic products occupy most of hair treatment agents on the market, it is necessary to develop a hair treatment product containing antioxidants useful for the human body. In this study, the effect of maple leaf extract on the mechanical change of colored hair was analyzed to investigate the potential of maple leaf extract as a hair treatment agent to improve damaged hair and improve hair health. It is considered that this study will be used as basic data for the development of hair beauty products using natural products in the future.

• Korean journal of applied entomology
• /
• v.31 no.2
• /
• pp.144-152
• /
• 1992

The juvenile hormone(JH) titers and juvenile hormone esterase (JHE) activities were mea¬sured in larval homogenates of the chestnut gall waL,J, Dryocosmus kuriphilus Yasumatsu, parasiting a susceptible and two resistant chestnut ( Cheuk-Pa, and Dan- Tak) varieties by GLC, Galleria wax test and Liquid scintilation counter. JH of the chestnut gall wasp was identified as JH- I. Their juvenile hormone titers were 35,800 GU/g(Cheuk-Pa), 30,900 GU/g (Dan-Tak), and 28,600 GU/g(susceptible variety). The juvenile hormone esterase activities were 1.48 n mole/min/ml(Cheuk-Pa), 1.63 n mole/min/ml(Dan- Tak), and 1.89 n mole/mini ml(susceptible variety). JH titer activity of the chestnut gall wasp parasiting resistant varie¬ties were higher than that from susceptible, whereas their JHE activity was higher in those from susceptible variety than those from resitant varieties. JH titer and JH specific esterase activity was inversely proportional.

• Journal of Microbiology and Biotechnology
• /
• v.18 no.5
• /
• pp.852-858
• /
• 2008

An extracellular protease (Mc1) was isolated from the nematode-trapping fungus Monacrosporium cystosporium by gel filtration, anion-exchange, and hydrophobic interaction chromatographies. This protease had a molecular mass of approximately 38 kDa and displayed an optimal activity at pH 7-9 and $56^{\circ}C$ (over 30 min). Its proteolytic activity was highly sensitive to the serine protease inhibitor PMSF (phenylmethylsulfonylfluoride, 0.1 mM), indicating that it belonged to the serine-type peptidase group. The Michaelis constant ($K_m$) and $V_max$ for substrate N-Suc-Ala-Ala-Pro-Phe-pNA were $1.67{\times}10^{-4}\;M$ and 0.6071 $OD_{410}$ per 30 s, respectively. This protease could degrade a broad range of substrates including casein, gelatin, BSA (bovine serum albumin), and nematode cuticle. Moreover, the enzyme could immobilize the free-living nematode Panagrellus redivivus and the pine wood nematode Bursaphelenchus xylophilus, suggesting that it might playa role in infection against nematodes. The encoding gene of Mc1 was composed of one intron and two exons, coding for a polypeptide of 405 amino acid residues. The deduced amino acid sequence of Mcl showed 61.4-91.9% identity to serine proteases from other nematode-trapping fungi. Our results identified that Mcl possessed biochemical properties including optimal reaction condition and substrate preference that are different from previously identified serine proteases.

• Korean Journal of Veterinary Research
• /
• v.42 no.1
• /
• pp.109-113
• /
• 2002

This is the first case report of Stephanurus dentatus infection of a feral pig in Korea. In late April, 2000, a weakened feral pig was caught by blow gun from a very low level mountain near the Gyeongsang National University. We autopsied the feral pig in the laboratory of veterinary anatomy at the College of Veterinary Medicine. A total of 27 adult parasites, 11 females and 16 males, and numerous eggs were observed from the cysts formed in the perirenal tissues and ureters. The average size of males was $25.1{\pm}3.2mm$ long and of the females was $34.2{\pm}2.9mm$. The worms were stout, the females being about 2mm broad, and the internal organs were partly visible through the cuticle. The shape of thin-shelled eggs found in the cysts of perirenal tissues and ureter was ellisoidal and oval, and measured $40{\sim}65{\times}90{\sim}115{\mu}m$. The adult parasites were found in cysts which varied from 0.6 to 4cm in diameter, each cyst usually containing a pair of adult worms embedded in green pus. The ureter was thickened and almost occluded, with consequent hydronephrosis.

• Journal of Life Science
• /
• v.15 no.6 s.73
• /
• pp.889-894
• /
• 2005

This experiment was carried out to investigate the effects of simulated acid rain (SAR) in the shoot growth and internal structure of Arabidopsis thaliana. In the shoot growth, the plants treated with SAR (pH 3.0) for 15 days showed no morphological change compared to the control plants. Some change was observed in the internal structure of the stems: the epidermis and cortex tissues of the stems treated with SAR were partly damaged. The plants treated with SAR showed no noticeable difference compared to the control plants, but morphological changes were observed in the leaf. The leaves of the plants treated with SAR showed many white necrotic spots on the part of upper epidermis. A light microscopic examination of the leaves with necrotic spots showed that the upper epidermis was severely compressed with the damaged cuticle layer and the mesophyll cells were also damaged and compressed. However, noticeable structural change of vascular bundle cells was not observed.

• Journal of Veterinary Clinics
• /
• v.36 no.6
• /
• pp.330-335
• /
• 2019

Apharyngostrigea ibis (Trematoda: Strigeidae) were obtained from the small intestine of two black-crowned night herons (Nycticorax nycticorax) and three grey herons (Ardea cinerea jouyi) between July 2006 and September 2018 in Daejeon metropolitan city and Kangwon province, Republic of Korea. The body is covered with a relatively thick cuticle, devoid of spines, and bipartite. The body measures at 2.3-3.33 × 0.86-1.20 mm, and the fore-body is ventrally concave. The oral sucker leads into a short esophagus that is devoid of a muscular pharynx. The worm was studied with a scanning electron microscope for the first time resulting in the detection of a pair of lappets located at the bilateral portion of the oral sucker. This is the first record of A. ibis in the Republic of Korea.