• Molecules and Cells
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• v.39 no.10
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• pp.768-775
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• 2016

The Arabidopsis female gametophyte contains seven cells with eight haploid nuclei buried within layers of sporophytic tissue. Following double fertilization, the egg and central cells of the gametophyte develop into the embryo and endosperm of the seed, respectively. The epigenetic status of the central cell has long presented an enigma due both to its inaccessibility, and the fascinating epigenome of the endosperm, thought to have been inherited from the central cell following activity of the DEMETER demethylase enzyme, prior to fertilization. Here, we present for the first time, a method to isolate pure populations of Arabidopsis central cell nuclei. Utilizing a protocol designed to isolate leaf mesophyll protoplasts, we systematically optimized each step in order to efficiently separate central cells from the female gametophyte. We use initial manual pistil dissection followed by the derivation of central cell protoplasts, during which process the central cell emerges from the micropylar pole of the embryo sac. Then, we use a modified version of the Isolation of Nuclei TAgged in specific Cell Types (INTACT) protocol to purify central cell nuclei, resulting in a purity of 75-90% and a yield sufficient to undertake downstream molecular analyses. We find that the process is highly dependent on the health of the original plant tissue used, and the efficiency of protoplasting solution infiltration into the gametophyte. By isolating pure central cell populations, we have enabled elucidation of the physiology of this rare cell type, which in the future will provide novel insights into Arabidopsis reproduction.

• Proceedings of the Plant Resources Society of Korea Conference
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• 2023.04a
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• pp.33-33
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• 2023

Potatoes are the world's 4th major food crop after maize, rice, and wheat and also are a staple food for 1.3 billion people. Due to their wide adaptability to various environmental conditions, their yeild capacity, and high commercial value, potatoes have contributed to global food security. Many potato germplasms are commonly preserved as whole plants in fields or in storage to maintain their particular genetic combinations. However, field maintenance is expensive and has the risk of potential losses from diseases, pests, plant ageing and climate change. Over the past four decades, meaningful efforts have been made toward the safe long-term conservation of potatoes through cryopreservation methods such as droplet-vitrification. In this study, we tested 4 Korean potato varieties('Golden Egg', 'Golden Ball', 'Ja-Young' and 'Ha-Ryeong') with the modified potato droplet -vitrification protocol. Potato shoot tips are precultured in a sucrose-enriched medium(0.3 and 0.7M for 7 and 17hrs, respectively) and submitted to a loading step with C4 solution for osmoprotection. The treated explants were dehydrated with Plant Vitrification Solution(PVS)2 which is 80% A3 solution in ice for 30 minutes. Thawing and unloading steps were performed with 0.8M sucrose solution for 30 sec(40℃) followed by 30min(25℃, room temperature). In a potato post-culture medium(MS+0.1 mg·L^-1 GA₃+0.1 mg·L^-1 kinetin), we obtained a survival rates of post-thawed explants ranging 16.1-82.2%. The results suggest that modified and optimized protocols are required dependinig on every cultivar, genetic and ecological types. To achieve higher survival and regeneration rates, each step within the cryoprocedure must be carefully optimized.

• CELLMED
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• v.4 no.1
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• pp.4.1-4.4
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• 2014

Gynura segetum, family Asteraceae is a cultivated species and can be found growing in the tropical regions of Indonesia and Malaysia. The plant is known for its use for the treatment of cancer, inflammation, diabetes, hypertension and skin afflictions. In the current study, anti-inflammatory effect of Gynura segetum leaf has been investigated. The present study investigated the in vivo anti-inflammatory effect of Gynura segetum leaf by using hen's egg test-chorioallantoic membrane (HET-CAM) assay. Different solvent extract of Gynura segetum leaf were tested, the most active methanol extract was further fractionated and tested. Among the extracts tested, the methanol extract showed a significant good anti-inflammatory effect (76.8% inhibition at 50 ${\mu}g/disc$) on the HET-CAM assay as compared with the anti-inflammatory drug indomethacin (82.1% inhibition). However, the fractionated sample exhibited a significantly lower activity in comparison to crude methanol extract. The results demonstrated that Gynura segetum leaf displayed remarkable anti-inflammatory effects, which support the folkloric uses of this plant for treatment of inflammation.

• Journal of Applied Biological Chemistry
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• v.48 no.4
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• pp.161-166
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• 2005

Among 24 isolates of fluorescent Pseudomonads, 5 isolates named as LPT1, LPT2, LPT3, LPT4 and LPT5 were screened in vitro for their nematicidal activity against cyst forming nematode, Heterodera cajani causing patchiness, poor and stunting growth besides discoloration in Sesamum indicum. Second stage juveniles of H. cajani hatched from egg masses were collected from roots of host plant and subjected to fresh and heat-treated culture filtrate of isolates for 24 h. Mortality of H. cajani was recorded on the basis of parameters used for test organism bioassay. Among these isolates, Pseudomonas aeruginosa LPT5 caused maximum mortality towards second stage juvenile of H. cajani in vitro. Five isolates were used as seed coating for the management of cyst forming nematode H. cajani on sesame in green house condition. The strains LPT5 was better than the other strains in reducing the population of H. cajani both in vitro and in vivo. The reduction in cyst and juveniles population was found to be 49 and 60%, respectively when seeds were coated with strain LPT5. Among other strains, LPT4 was also found to inhibit the cyst and juveniles population 12 and 36% respectively. Increases in early vegetative plant growth parameters recorded in both in vitro and in vivo further revealed the significance of indigenous bacteria in comparison to introduced strain.

• Korean journal of applied entomology
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• v.56 no.1
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• pp.87-92
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• 2017

The Samurai wasp, Trissolcus japonicus (Ashmead) (Hymenoptera: Platygasteridae) is recognized as a solitary parasitoid on eggs of the stink bug, Halyomorpha halys (Stål) (Hemiptera: Pentatomidae), an economic pest causing severe damage to fruits, in South Korea. The wasp appears to be a potential biological agent of the pest. In addition, T. itoi Ryu and T. nigripedius (Nakagawa) were found to parasitize eggs of Eurydema gebleri Kolenati and Dolycoris baccarum Linnaeus, respectively. Diagnostic characters and photographs are provided for identification, and host records of Korean Trissolcus species are also given.

• Research in Plant Disease
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• v.7 no.2
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• pp.69-79
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• 2001

Meloidogyne arenaria race 2 (59%) is widely distributed, followed by M. incognita race 1 (23%), and an unknown race of M. incognita (18 ％) in greenhouses in southern Korea. The key character to distinguish between M. arenaria and M. incognita is excretory pore in female head. When oriental melon, Cucumis melo L., grafted on Shintozoa (Cucurbit maxima x Cu. moschata) is transplanted in February in a plastic tunnel inside a greenhouse infested with M. arenaria, nematodes produced egg masses on roots at 40 days after transplanting and the soil juveniles (J2) population reach maximum in July to 3,817/100 ㎤. Juveniles are distributed relatively uniform over the 180-cm-wide row horizontally and the highest density occurs at 0-25 cm soil depth. For the control of root-knot nematodes, rice rotation, solarization, and soil addition treatments are the most effective (P=0.05); treatments reduce number of J2 over 90% and increase yield two times. Corn retation, fosthiazate, and soil drying treatment are moderately effective, while sesame and green onion rotations are not effective. The relationship between M. arenaria and yield of oriental melon is adequately described by a linear regression model. In the test with wild Cucumis genetic sources introduced from U.S.Dept. of Agriculture (USDA), one of C.heptadactylus, two of C.anguria, two of C. anguria var. longaculeatus, nine of C. metuliferus are resistant to both species of root-knot nematodes.

• Journal of the Korean Society of Food Science and Nutrition
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• v.23 no.2
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• pp.315-321
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• 1994

In order to prevent the postharvest decay and to promote the freshness retention of fruits and vegetables grapefruit seed extract(GFSE), natural microorganism control agent, was applied to the preservation of fresh fruits and vegetables. Freshfruits and vegetables treated with GFSE and stored in polyethylene film (0.1mm) at 1$0^{\circ}C$-15$^{\circ}C$ of natural low temperature low kept better qualities in color and texture than the GFSE -not- treated control. The treatment using GFSE ina 250ppm to 500ppm concentration seemed to be an effective one for the control of Botrytis cinerea isolated in red wine grapes. After 4 weeks of storage the firmness rate of cucumbers treated with the dilute GFSE was four times higher than that of non-treated ones. GFSE showed effective inhibitory action towards plant pathological bacteria and fungi which were involved in the decay of fruits and vegetables. Minimum inhibitory concentrations of GFSE towards them were in the range of 250ppm to 500ppm .Direct visualization of microbial cells and spores using electron microscopy showed microbial cells and fungal spores the function of which was destroyed by treating with the dilute solutions of GFSE. It was observed that GFSE would reduced disease damages and have bactericide & fungicide properties during the storage of such fruits and vegetables as egg plant, wild edible greens , kumquat, and kiwi fruit.

• Korean journal of applied entomology
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• v.25 no.2 s.67
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• pp.85-92
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• 1986

This study was conducted to investigate host plant, bionomics, and damage on Bamboo Leaf Rollers in Chonnam area. Species of the leaf rollers attacking the bamboo trees in Chonnam area were Microstega jessica (Butler) and Sinibotys evenoralis (Walker). Among these species, M. jessica (B.) and S. evenoralis (W.) were observed in Damyang but S. evenoralis (W.) alone was found in Naju and Hwasoon. Among the 4 host plant species observed, Phyllostachys nigra var. henonis S., and P. nigra M. were first recorded as host plants of M. jessica (B.), and P. nigra var. henonis (S.) as host plant of S. evenoralis (W.). The occurrence of the M. jessica (B). was once a year with the peak about late May, whereas the occurrence of S. evenoralis (W.) was 2 times a year and the peaks were early June and mid-July, respectively. The average periods of each stage of M. jessica (B.) were 8 days for egg, 293 days for larva, 16 days for pupa, and the longevity of the adult was 12 days for females and 9 days for males. The average periods of each stage of S. evenoralis (W.) were in 1st generation, 11 days for egg, 28 days for larva, 12 days for pupa, and the longevity of the adults was 18 days for females and 15 days for males; and 2nd generation was 7 days for egg, 261 days for larva, 20 days for pupa, and the longevity of the adults was 11 days for females and 10 days for males. The time of most adult emergence of M. jessica (B.) was from 6 p.m. to 4 a.m. and the peak was 8 p.m. to 10 p.m. M. jessica (B,) overwintered as 6th instals in Bamboo shoot sheath but S. evenoralis (W.) overwintered as $1st{\sim}2nd$ instals on the tree leaves of Bamboo. The percentage of damaged leaves with different heights of Bamboo trees were 67.1% at upper portion, 19.0% at middle portion, 14.0% at lower portion. The percentage of damaged loaves with different Bamboo species was 57.0% on P. nigra var. henonis S., 36.5% on P. bambusoides S. et Z., 14.5% on P. pubescens M.. It was showed highly significant negative correlation between percentage of damaged bamboo leaves an tree growth stages.($r=-0.739^{**}$)

• Korean Journal of Poultry Science
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• v.8 no.2
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• pp.55-68
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• 1981

Calcium and phosphorus are not only indispensable for the bone formation and body fluids equilibrium but also are major components of egg shell. It is nutritionally important, therefore, to investigate the metabolism of calcium and phosphorus and to search for optimum requirement of calcium and phosphorus and the availability of various sources of calcium an4 phosphorus by poultry. An attempt was made to review the nutrition of calcium and phosphorus in poultry diets. 1, Calcium and phosphorus have great interrelationship with vitamin D in their metabolisms. 2. Most of the plant-origin phosphorus are existing in phytic form and it leads to low availability when used in poultry rations, although calcium and phosphorus present in animal-origin or mineral supplements are highly available in general. 3. Calcium and phosphorus requirement from existing information indicated that 1.0% calcium and 0.7% phosphorus for broiler and egg-type chicks, and 3.5% calcium and 0.4% phosphorus for laying hen. 4. It has been recommended that calcium and phosphorus level should be increased when the feed intake was decreased or when the egg Production rate was higher or when the hens are old. 5. Mono-, ci-, tri-, calcium phosphate, calcium carbonate, bone meal, limestone and oyster shell u the most readily available among various sources of calcium phosphorus supplements. Soft rock phosphate, deflourinated phosphate and gypsum are somewhat inferior to the previous ones in bioavailability. 6. The effect of particle size of calcium supplements on egg shell quality and egg production rate is not yet clearly defined but recent works showed that oyster shell is more available when it was coarse and limestone is more available when it was fine in panicle. size. 7. Present data indicated that mixed feeding of oyster shell and limestone is superior to the single feeding of each on laying performance. 8. Significant interaction between phosphorus and sodium was observed, that is, excessive sodium decreased egg production in layer and body weight growth in broiler in the low phosphorus diets but increased them in the high phosphorus diets.

• Proceedings of the Korean Society for Bio-Environment Control Conference
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• 2005.10a
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• pp.159-162
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• 2005