• 한국식물생명공학회:학술대회논문집
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• 한국식물생명공학회 2005년도 추계학술대회 및 한일 식물생명공학 심포지엄
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• pp.330-330
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• 2005

• 한국식물생명공학회:학술대회논문집
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• 한국식물생명공학회 2005년도 추계학술대회 및 한일 식물생명공학 심포지엄
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• pp.331-331
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• 2005

• Journal of the Korean Wood Science and Technology
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• 제52권4호
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• pp.404-404
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• 2024

• Journal of the Korean Wood Science and Technology
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• 제10권3호
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• pp.167-167
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• 1982

Italian poplar (Populus euramericana) rotary veneers were press-dried and air-dried to study drying curves, thickness shrinkage and width shrinkage of them under several drying conditions such as drying temperatures and veneer thicknesses. The results of the study are summarized as follows; 1. In press-drying, drying times from green condition to about final moisture content of 10 percent with veneer thickness of 0.6mm by platen temperatures required about 10 minutes at platen temperature of $100^{\circ}C$, 3 minutes at $110^{\circ}C$, 1 minute at $120^{\circ}C$ and $130^{\circ}C$, respectively. 2. In press, drying, drying times from green condition to about final moisture content of 10 percent by veneer thicknesses required 2 minutes at veneer thickness of 0.6mm, 4 minutes at 1.2mm,6 minutes at 1.8mm and 9 minutes at 3.6mm, respectively. 3. In air-drying, drying times from green condition to air-dried moisture content by veneer thicknesses required 15 hours at veneer thickness of 0.6mm, 18 hours at 1.2mm and 23 hours at 2.4mm, respectively. 4. Thickness shrinkage of press-drying was remarkably greater than that of air-drying, but width shrinkage of press-drying was rather smaller. 5. Difference of thickness shrinkage among platen temperatures was insignificant, and width shrinkage at platen temperature of $130^{\circ}C$ was the least.

• 펄프종이기술
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• 제36권5호
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• pp.69-77
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• 2004

Degradations of pine, yellow poplar and sweet gum by two fungi, Pycnoporus cinnabarinus and Trichophyton rubrum LSK-27 were investigated. P. cinabarinus degraded pine block samples much faster than T rub rum LSK-27, whereas P. cinnabarinus and T rubrum LSK-27 degraded yellow poplar and sweet gum at almost the same rate. In an effort to get a better understanding of how fungi degrade lignin in wood, contents of various functional groups were analyzed. After three-months of degradation of pine flour by these fungi, the following changes were observed: an increase in condensed phenolic OH group and carboxylic acid group content, a decrease in the guaiacyl phenolic OH content, and little change of aliphatic OH group content. Further studies in the degradation of pine flour by P. cinnabarinus indicated that the increase in condensed phenolic OH group content and the decrease in guaiacyl phenolic OH group content occurred in the first month of the degradation. The changes of functional group contents in the degradation of unbleached softwood kraft pulp by P. cinnabarinus had the same trends as those in the degradation of pine flour. That is, structural alteration of lignin due to the kraft pulping process had little effect on how P. cinnabarinus degraded lignin.

• Journal of Plant Biotechnology
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• 제3권3호
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• pp.135-140
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• 2001

An Agrobacterium tumefaciens LBA4404 (harboring antisense OMT gene)-mediated transformation method has been developed for poplar (P.nigra x maximowiczii) using prolonging co-cultivation time. Explants on LT (longterm) were induced transgenic calli one month earlier than those from ST (short-term) co-cultivation and remained healthier on LT than ST. With this approach, LT method reduced time to produce transgenic calli. Shoots were successfully regenerated from transgenic calli on SIM (Shoot Induction Medium) and rooted well on the basal medium spontaneously. The presence of antisense OMT gene was verified both by PCR and Southern analysis. Each transgenic poplar was phenotypically indishtinguishable when compared with controls for their growth pattern, leaf morphologies and xylem coloration.

• 임산에너지
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• 제20권2호
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• pp.20-27
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• 2001

글루코스 생산을 위한 효과적인 방법을 개발하기 위해서 cellulase에 의한 현사시 나무의 효소가수분해를 실시하였다. 목재의 효소가수분해는 미생물이 생산한 효소를 사용하여 글루코스를 생산하는 반응이다. 이렇게 얻어진 글루코스는 발효에 의해 쉽게 에탄올로 변환시킬 수 있다. 에탄올은 아세톤이나 부탄올, 시트릭산 그리고 락틴산을 제조하는 원료물질이나 석유자원을 대체할 수 있는 대체에너지 자원이다. 셀룰로오스의 효소가수분해 기작은 endo-cellulase, exo-cellulase 그리고 β-D-glucosidase라는 세 개의 서로 다른 형태의 효소가 연속적인 반웅에 의해 일어난다고 설명되어지고 있다. 본 실험의 목적은 다양한 농도의 수산화나트륨으로 현사시나무를 전처리 하여 이러한 전처리가 셀룰로오스의 결정화도와 리그닌함량에 미치는 영향과 가수분해율과의 관계를 조사하였다.

• Journal of Plant Biotechnology
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• 제3권2호
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• pp.83-88
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• 2001

A cell culture system of poplar (Populus alba x P.glandulosa) was established to test four different methods for evaluation of cellular stresses. Two different kinds of stresses were given to the cultures by adding either Pb(NO$_3$)$_2$ or paraquat and the cellular responses were monitored during a week period. While fresh weight reduction was observable in two days after the treatment of Pb(NO$_3$)$_2$, such changes were apparent only in later stage in paraquat treated cultures. Cells in paraquat treated cultures in the first 3 days showed no alteration in fresh weight as compared to untreated cultures, but had their MTT reducing activities completely inhibited. Neither Evans blue staining nor ion conductivity of the medium was consistent with fresh weight changes of the cultures. Overall, cell clumps formed during suspension culture appeared to interfere with staining and washing reactions and thus cause the assays unreliable. Among the four methods examined, fresh weight changes and MTT reducing activity appeared to be the most reliable and consistent.

• 한국산림과학회지
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• 제94권4호통권161호
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• pp.236-242
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• 2005

다양한 광조건에서 식물의 생장조절에 관여하는 광수용체인 phytochrome B(PhyB) 유전자를 교잡종 포플러 수항1호에서 분리하였다. 염기서열분석 결과, PhyB cDNA는 길이가 3,456bp 이었으며 1,156개의 아미노산으로 구성된 단백질을 암호화하고 있는 것으로 나타났다. PhyB 단백질은 아미노산 수준에서 Populus balsamfera PhyB1과 98%의 높은 상동성을 나타내었다. Northern blot 분석 결과, PhyB 유전자는 광조건에서는 높은 수준으로 발현되지만, 암조건에서는 발현되지 않는 것으로 나타났다. 본 연구의 결과들을 종합하여 볼 때 PhyB는 빛에 의하여 발현이 유도되며 광수용체 역할을 하는 것으로 여겨진다.

• Journal of the Korean Wood Science and Technology
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• 제28권4호
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• pp.17-24
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• 2000

The peroxidase activity was localized cytochemically to get an insight into its precise function in lignin biosynthesis. In this work, cerium chloride ($CeCl_3$) was used as a trapping agent for hydrogen peroxide ($H_2O_2$) generated from peroxidase. Seasonal variation of peroxidase activities in cambial region of Populus, Pinus, and Ginkgo was investigated at subcellular levels. Under transmission electron microscopy, electron dense deposits of cerium perhydroxide formed by reaction with $H_2O_2$ were observed in cambium and its immediate derivatives. The staining with $CeCl_3$ in cambium varied with growth seasons. The strongest $H_2O_2$ accumulation, regardless of tree species, appeared in May. Staining pattern of $CeCl_3$ in the cambium of poplar indicated that the production of peroxidase started in March before the opening of buds and reached the highest in May and then declined in August. Ginkgo and Pinus showed relatively late generation of $H_2O_2$ production when compared with Populus. Although Ginkgo and Pinus are classified into gymnosperms, however, the generation of peroxidase production and its duration was different from each other. Little staining appeared in all the tree samples collected in September before falling the leaves.