• Proceedings of the Korean Society of Plant Biotechnology Conference
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• 2005.04a
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• pp.137-137
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• 2005

• Journal of Ecology and Environment
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• v.42 no.3
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• pp.90-102
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• 2018

Background: We sought to understand the relationship between the seed bank and vegetation in abandoned rice paddies in South Korea, in order to guide management of these sites. We investigated the floristic composition and species richness of the soil seed bank and ground vegetation in former paddies along three seral gradients (wet meadow, young forest, and mature forest) in Gwangneung Forest Biosphere Reserve. Results: Seed bank samples contained 59 species, of which the dominant families were Cyperaceae, Gramineae, and Polygonaceae. Species richness and seedling density (59 taxa and 19,121 germinants from all samples) were high. Carex spp. (11, 921 germinants) were the dominant taxa. The species composition in the seed bank changed gradually as the land transitioned from wet meadow to mature forest. Sørensen's index of similarity between above- and below-ground vegetation was 29.3% for wet meadow, 10.8% for young forest, and 2.1% for mature forest. Germinant density also declined, with 10, 256 germinants for wet meadow, 6445 germinants for young forest, and 2420 germinants for mature forest. Conclusions: Changes in aboveground environment and life history traits such as amphicarpic plants, likely affect the composition of soil seed bank species. Abandoned paddy fields may be good sites for restoration of wetland forest and conservation of wetland habitat. Some intervention may be required to promote the recovery of a natural species assemblage.

• Journal of Plant Biotechnology
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• v.32 no.3
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• pp.201-207
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• 2005

This study was conducted to examine the effect of BA and NAA on adventitious bud induction from in vitro germinants E. pellita. The capacity of adventitious bud formation greatly depends on juvenility and explants origin; the more juvenile materials are the better ability to form adventitious buds even in in vitro raised plantlets. In case of in vitro germinants, 7 day old plantlets showed a better morphological response than did 14 day old ones in the induction of adventitious buds. The capacity to show morphological response was in decreasing order : cotyledons> petioles> roots. Ho adventitious buds formed when root segments were used as culture material. And optimum medium appeared to be MS + 0.5 mg/L BA and 0.2 mg/L NAA. Adventitious buds could be developed into multiple shoots and regenerated normal plantlets on DKW medium plus 0.2 mg/L BA and 0.01 mg/L NAA.

• Food Science and Biotechnology
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• v.18 no.2
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• pp.336-342
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• 2009

To confirm the antimicobial mechanism of Torilis japonica, antimicrobial profile was observed on various spore conditions by combining 0.1% (3 mM) torilin with antimicrobial activity and 0.27% water fraction with germinants. A 75% ethanol extract of T. japonica fruit reduced Bacillus subtilis ATCC 6633 spore counts by 3 log cycles and reduced the vegetative cells to undetectable level (by about 6 log cycles) (both in terms of CFU/mL). Further fractionating the ethanol extract into n-hexane and water fractions revealed that the former reduced the spore count by 1 log cycle whereas the latter had no effect. The antimicrobial active compound was isolated and purified from the hexane layer, and identified as torilin ($C_{22}H_{32}O_5$). The water fraction of the ethanol layer did not show antimicrobial activity, whereas the antimicrobial effect of 0.1% (3 mM) torilin was significantly enhanced in the presence of the water fraction (0.27%). This result can be explained by synergistic effects of the water fraction containing considerable amounts of germinants such as L-alanine and K+ ions that triggered germination.

• Journal of Microbiology and Biotechnology
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• v.23 no.1
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• pp.15-21
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• 2013

We previously observed that Bacillus subtilis spores from sspE mutants presented a lower germination capacity in media containing high salt concentrations (0.9M NaCl). This deficiency was attributed to the absence of SASP-E (gamma-type small-acid-soluble protein), rich in osmocompatible amino acids released by degradation. Herein we observed that, in addition, this mutant spore presented a reduced capacity to use L-alanine as germinant (L-ala pathway), required longer times to germinate in calcium dipicolinate ($Ca^{2+}$-DPA), but germinated well in asparagine, glucose, fructose, and potassium chloride (AGFK pathway). Moreover, mild sonic treatment of mutant spores partially recovered their germination capacity in L-ala. Spore qualities were also altered, since sporulating colonies from the sspE mutant showed a pale brownish color, a higher adherence to agar plates, and lower autofluorescence, properties related to their spore coat content. Furthermore, biochemical analysis showed a reduced partition in hexadecane and a higher content of $Ca^{2+}$-DPA when compared with its isogenic wild-type control. Coat protein preparations showed a different electrophoretic pattern, in particular when detected with antibodies against CotG and CotE. The complementation with a wild-type sspE gene in a plasmid allowed for recovering the wild-type coat phenotype. This is the first report of a direct involvement of SASP-E in the spore coat assembly during the differentiation program of sporulation.

• Proceedings of the Plant Resources Society of Korea Conference
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• 2003.04a
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• pp.61-62
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• 2003

Clonal propagation of high-value forest trees through somatic embryogenesis (SE) has the potential to rapidly capture the benefits of breeding or genetic engineering programs and to improve raw material uniformity and quality. A major barrier to the commercialization of this technology is the low quality of the resulting embryos. Several factors limit commercialization of SE for Corsican pine, including low initiation rates, low culture survival, culture decline causing low or no embryo production, and inability of somatic embryos to fully mature, resulting in low germination and reduced vigour of somatic seedlings. The objective was to develop a Corsican pine maturation medium that would produce cotyledonary embryos capable of germination. Treatments were arranged in a completely randomized design. Data were analyzed by analysis of variance, and significant differences between treatments determined by multiple range test at P=0.05. Corsican pine (Pinus nigra var. maritima) cultures were initiated on modified !P6 medium. Modifications of the same media were used for culture multiplication and maintenance. Embryogenic cultures were maintained on the same medium semi solidified with 2.5 g/l Gelrite. A maturation medium, capable of promoting the development of Corsican pine somatic embryos that can germinate, is a combination of iP6 modified salts, 2% maltose, 13% polyethylene glycol (PEG), 5 mg!l abscisic acid (ABA), and 2.5 g/l Gelrite. After initiation and once enough tissue developed they were grown in liquid medium. Embryogenic cell suspensions were established by adding 0.951.05 g of 10- to 14-day-old semisolid-grown embryogenic tissue to 9 ml of liquid maintenance media in a 250ml Erlenmeyer flask. Cultures were then incubated in the dark at 2022$^{\circ}$C and rotated at 120 rpm. After 2.53 months on maturation medium, somatic embryos were selected that exhibited normal embryo shape. Ten embryos were placed horizontally on 20 ml of either germination medium ($\frac{2}{1}$strength Murashige and Skoog (1962) salts with 2.5 g/l activated charcoal) or same medium with copper sulphate adjusted to 0.25 mg/1 to compensate for copper adsorption by activated carbon. 2% and 4% maltose was substituted by 7.5% and 13% PEG respectively to improve the yield of the embryos. Substitution of' maltose with PEG was clearly beneficial to embryo development. When 2% of the maltose was replaced with 7.5% PEG, many embryos developed to large bullet-shaped embryos. At latter stages of development most embryos callused and stopped development. A few short, barrel-shaped cotyledonary embryos formed that were covered by callus on the sides and base. When 4% of the maltose was removed and substituted with 13% PEG, the embryos developed further, emerging from the callus and increasing yield slightly. Microscopic examination of the cultures showed differing morphologies, varying from mostly single cells or clumps to well-formed somatic embryos that resembled early zygotic embryos only liquid cultures with organized early-stag. A procedure for converting and acclimating germinants to growth in soil and greenhouse conditions is also tested. Seedling conversion and growth were highly related to the quality of the germinant at the time of planting. Germinants with larger shoots, longer, straighter hypocotyls and longer roots performed best. When mature zygotic embryos germinate the root emerges, before or coincident with the shoot. In contrast, somatic embryos germinate in reverse sequence, with the cotyledons greening first, then shoot emergence and then, much later, if at all, the appearance of the root. Somatic seedlings, produced from the maturation medium, showed 100% survival when planted in a field setting. Somatic seedlings showed normal yearly growth relative to standard seedlings from natural seed.