• Journal of Plant Biotechnology
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• v.44 no.1
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• pp.61-68
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• 2017

Gibberellic Acid-Stimulated Arabidopsis (GASA) genes are involved in plant hormone signaling, cell division and elongation, as well as in responses to stress conditions in plants. In this study, we isolated a GASA gene from hybrid poplar (Populus alba ${\times}$ P. glandulosa) and analyzed its physiological phenotype and molecular functions in poplar. PagGASA cDNA encodes a putative protein composed of 95 amino acids containing an N-terminal signal peptide and a conservative cysteine-rich C-terminal domain. Southern blot analysis revealed that one or two copies of the PagGASA are present in the poplar genome. The PagGASA transcripts were highly detected in flowers and roots. Moreover, the expression of PagGASA was induced by growth hormone (gibberellic acid) and stress hormones (abscisic acid, jasmonic acid, and salicylic acid). By using transgenic analysis, we showed that the upregulation of PagGASA in poplar provides high tolerance to drought stress. Therefore, our results suggest that PagGASA plays an important role in drought stress tolerance via stress-related plant hormone signaling in poplar.

• Proceedings of the Korean Society of Soil and Groundwater Environment Conference
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• 2002.04a
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• pp.311-314
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• 2002

국내에서 자생하는 포플러중 현사시, 양황철, 이태리포플러를 대상으로 제초제인 atrazine의 제거특성을 조사하였다 Atrazine이 포플러에 미치는 독성을 평가하고, 식물체에 의한 atrazine 제거효율 및 제거속도를 조사하였다. 또한 식물체의 체내로의 흡수에 의해 atrazine이 제거되므로 식물체로 흡수된 후의 생물학적 변환 과정에 대해서도 조사하였다. 현사시, 양황철, 이태리포플러 모두 실험이 진행된 전범위의 농도에서 황백화현상, 낙엽증가, 생체량 감소와 같은 식물독성을 나타냈으며, 현사시인 경우 양황청 및 이태리 포플러에 비해 상대적으로 민감한 반응을 나타내었다. Atrazine 독성여부 평가의 하나로 초기 atrazine 농도가 증가할수록 현사시, 양황철, 이태리포플러의 증산량은 상대적으로 감소함을 관찰하였다. 포플러에 의한 atrazine 생물학적 변환실험에서는 atrazine이 중간생성물질인 HA, DEA, I)IA를 거쳐 ammeline을 포함한 HDAP로 전환되는 것을 확인하였다. 이 결과의 중요성은 atrazine 부산물은 상대적으로 독성이 적고, 미생물에 의해 어렵지 않게 완전 무기화할 수 있기 때문이다. 즉, 식물체내에서도 HBAP 이후 과정을 통한 분해가 이루어질 수 있는 가능성이 있다고 추측할 수 있다.

• Journal of Life Science
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• v.8 no.4
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• pp.443-448
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• 1998

We analyzed lignin content and wxpression of OMT gene during growth season in two hybrid poplar species. OMT gene expression was observed mainy in the developing secondary xylem where major quantity of lignin occurs. Lignin content in the xylem tissue increased as plant resumed growth in the spring and reached the highest in the late August. Change in lignin content was concurrent with that of OMT gene expression, indicating OMT is a key enzyme in lignin biosynthesis.

• Journal of Life Science
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• v.7 no.3
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• pp.172-175
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• 1997

Transgenic hybrid poplar subclones containing herbicide glyphosate resistant gene (aroA) were treated with ozone at the concentration of 100 nL L$^{-1}$ for 6 hr for 5 consecutive days. The foreign gene expression in leaves of all treated plants was reduced both at transcriptional and translational levels confirmed by Northern and Western blot analysis, respectively, as compared to non-treated control plants. These results indicated that the expression of foreign gene in transgenic plants could be affected by the environmental stresses. Thus, the performance of transgenic plants cultivated on field conditions may be lower than they are expected.

• Journal of Plant Biotechnology
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• v.31 no.1
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• pp.49-53
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• 2004

Shoot formation was investigated from in vitro cultivation of exotic hybrid poplar (Populus koreana ${\times}$ P. trichocarpa) with a specific stomatal character occurring both upper and lower surface of leaves. Two different explants (stem and leaf segment) of Peace poplar were cultured on half strength Murashige and Skoog (MS) basal medium supplemented with the various concentrations of thidiazuron as a plant growth regulator. Most adventitious shoots were produced from excised ends of stem or mid-veins of leaf segments. The highest average numbers of shoots were 7.1 and 5.3 with the treatments of 0.02mg/L TDZ in both explants of stem and leaf segment. The highest shooting rates were achieved to 83.3％ and 47.6％ with the concentrations of 0.01mg/L and 0.02mg/L TDZ by axillary bud and leaf cultures, respectively.

• Journal of the Korean Wood Science and Technology
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• v.41 no.1
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• pp.1-11
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• 2013

In this study, we investigated chemical characteristics of solid residues obtained from inorganic acid hydrolysis of hybrid poplar (Populus alba ${\times}$ glandulosa). Different concentration (72, 36, 18%) of sulfuric acid and hydrochloric acid were used for first hydrolysis step and second hydrolysis step were carried out after equally dilution to 4%. Solid residues after consecutive two step hydrolysis were named to RS72 (Residue from Sulfuric acid 72%), RS36, RS18, as well as RC36 (Residue from hydroChloric acid 36%) and RC18, respectively. The yield of RS decreased from 71.2% to 21.4% with increasing sulfuric acid concentration in the first hydrolysis step, whereas that of RC showed little difference (67.0% to 65.0%), irrespective of hydrochloric acid concentration. The lignin content in solid residue was 23.6% for both of RS36 and RS18, 25.6% for RC36 and 27.3% for RC18, respectively. The results of pyrolyzer-GC/MS showed that 24 cellulose derivatives (Levoglucosan, Furfural) and 21 lignin derivatives (Guaiacol, Syringol) were detected. Thermogravimetric analysis indicated that the yield of char increased and maximum wieght loss rate decreased with increasing lignin portion of solid residue. Therefore, structure of lignin was condensed effectively by sulfuric acid and by high concentration of acid.

• Journal of Korean Society of Forest Science
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• v.106 no.2
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• pp.186-195
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• 2017

This research aims to study the physiological characteristics of poplar clones in Saemanguem reclaimed land where has lower minerals and bad drainage than those in paddy field. In July and August, different poplar clones including Populus euramericana clone (Venziano and L.Avanzo) and deltoides hybrid clone (97-18 and 97-19) showed different physiological characteristics. Physiological characteristics of P. euramericana clones were better than those of P. deltoides hybrid clones. Especially, the average net photosynthetic rate ($A_{net}$) of clone Venziano were $18.62{\mu}mol\;CO_2\;m^{-2}{\cdot}s^{-1}$ and $17.11{\mu}mol\;CO_2\;m^{-2}{\cdot}s^{-1}$, respectively. Those were the highest numerical values among other poplar clones. On the other, the total chlorophyll and carotenoid contents of P. deltoides hybrid clones were higher than those of P. euramericana clones in July. Particularly, the total chlorophyll content of clone 97-18 was $2.37mg{\cdot}g^{-1}FW$. In August, those of P. deltoides hybrid clones decreased than in July. In term of the physiological activity such as net photosynthetic rate and stomatal conductance of P. deltoides hybrid clones were much lower in August than in July. As a result, physiological characteristics of P. euramericana Venziano clone was superior than the other clones in Short rotation coppice (SRC) in Saemanguem area.

• Journal of Korean Society of Forest Science
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• v.94 no.4 s.161
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• pp.236-242
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• 2005

Phytochrome B (PhyB) gene, which is a photoreceptor that controls plant growth under various light conditions, was cloned from Chinese hybrid poplar 'Soohang 1'. Nucleotide sequence and deduced amino acid sequences PhyB cDNA of 'Soohang' is consisted with 3,456 nucleotides and 1,156 amino acids. The cloned PhyB fragment showed 98% homology of amino acid sequences with Populus balsamifera PhyB1. According to Northern blot analysis. PhyB was up-regulated by light, while PhyB transcript was not detected under dark condition. According to this study, the cloned PhyB is induced by light and functions as photoreceptor.

• Journal of Korean Society of Forest Science
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• v.57 no.1
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• pp.26-31
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• 1982

The hybrid poplar, populus alba ${\times}$ P.glandulosa $F_1$ shows a strong ability to produce root suckers. The relationship between crown density and root sucker was studied and the other factors that may be related to production of root sucker were also discussed. The possibility was also discussed to use its root suckers for fuelwood forests and vegetation in the area that erosion control is needed.

• Journal of Plant Biotechnology
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• v.6 no.1
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• pp.15-19
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• 2004

The expression of a chimeric transgene (nos-npt II) has been examined in 9 years old transgenic poplars (Populus koreana x P. nigra) growing in a nursery. The expression of the gene in twenty six independentely transformed plants were examined by 1) enzyme (NPT II) assay, 2) RT-PCR, and 3) resistance to kanamycin. High NPT II activities in young leaves of all the transformed plants were found even without a selection pressure for antibiotics for 9 years. However, the activity varied with the positions of leaves in the stem in that young leaves showed higher activity than did mature tissues. When leaf segments were cultured in the presence of 150 mg/l kanamycin, only those from young leaves produced vigorously growing callus. However, as in the case of NPTII assay, the leaf segments from mature leaves did not form callus well on the media. RT-PCR with nptII specific primers also showed that amplification products were observed only when RNAs from young tissues were used. The total RNA gel showed that while RNA in young leaves are relatively stable and in a large quantity, those in old leaves were mostly degraded. All the above results suggest that the gene is transcriptionally active only in young tissue even though it is attached to a constituitive promoter. Therefore, the expression of foreign gene in poplar plants seemed to be affected by the metabolic state of the cells and thus vary greatly with the developmental stages and the age of tissue.