• Journal of Plant Biotechnology
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• v.41 no.4
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• pp.194-200
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• 2014

Monodehydroascorbate reductase (MDHAR) is an important enzyme that plays a role in the detoxification of reactive oxygen species (ROS) by maintaining reduced pool of ascorbate through recycling the oxidized form of ascorbate. In this study, we isolated a PagMDHAR1 gene from Populus alba ${\times}$ P. glandulosa, and investigated its expression characteristics. The PagMDHAR1 cDNA encodes a putative 434 amino acids containing FAD- and NAD(P)H-binding domains. Southern blot analysis indicated that a single nuclear gene encodes this enzyme. Northern hybridization analysis revealed that PagMDHAR1 is highly expressed in both suspension cells and flower tissues, while its expression levels were enhanced by drought, salt, cold, wounding and ABA. Therefore, PagMDHAR1 might be expressed in response to abiotic stress through the ABA-mediated signaling pathway in this poplar species, suggesting that the PagMDHAR1 plays an important role in the defense mechanisms against oxidative stress.

• Journal of Korean Society of Forest Science
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• v.78 no.4
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• pp.372-380
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• 1989

The widely cultivated hybrid poplar Populus alba ${\times}$ P. glandulosa in Korea was transformed with Agrobacterium rhizogenes agropine type strain A4. Genetic transformation was confirmed by the presence of agropine. Alteration in growth rate of hairy roots was seen following changes in the dilution rate of medium and concentration of sucrose, suggesting that improved growth might be achieved by more precise manipulation of the nutrient medium. Plant regeneration occurred from transformed hairy roots on MS medium supplemented with 0.5 mg/l BAP. Transformed plantlets grown in vitro exhibited a more developed root system characterized by fast growth behavior in comparison to normal plantlets. This work demonstrates that the root transformation would be useful in improving plantlet establishment and growth through the effective root system.

• Journal of Plant Biotechnology
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• v.44 no.1
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• pp.69-75
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• 2017

Dormancy-associated protein (DRM) is involved in the dormancy physiology of plants and is conserved in almost all plant species. Recent studies found that DRM genes are involved in the abiotic stress response, and characterization studies of these genes have been conducted in several plants. However, few studies have focused on DRM genes in woody plants. Therefore, in this study, cDNA coding for DRM (PagDRM1) was isolated from poplar (Populus alba ${\times}$ P. glandulosa), and its structure and expression characteristics were investigated. PagDRM1 encodes a putative protein composed of 123 amino acids, and the protein contains two conserved domains (Domain I and Domain II). PagDRM1 is present as one or two copies in the poplar genome. Its expression level was highest in the stem, followed by mature leaves, roots, and flowers. During the growth of cultured cells in suspension, PagDRM1 was highly expressed from the late-exponential phase to the stationary phase. In addition, PagDRM1 expression increased in response to drought, salt stress, and treatment with plant hormones (e.g., abscisic acid and gibberellic acid). Therefore, we suggested that PagDRM1 not only plays an important role in the induction of dormancy, but also contributes to stress tolerance in plants.

• Journal of Korean Society of Forest Science
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• v.103 no.2
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• pp.189-195
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• 2014

Basic leucine zipper (bZIP) protein is a regulatory transcription factor that plays crucial roles in growth, development and stress response of plant. In this study, we isolated a PagbZIP1 gene that belonged to Group SE3 of bZIP from Populus alba ${\times}$ P. glandulosa, and investigated its expressional characteristics. The PagbZIP1 is 844 base pairs long and encodes a putative 144-amino-acid protein with an expected molecular mass of 16.6 kDa. The PagbZIP1 has two conserved domains including the basic and leucine zipper portions. Southern blot analysis revealed that two copies of the gene are presented in the poplar genome. PagbZIP1 was specifically expressed in the root and suspension cells. Moreover, the expression of PagbZIP1 was induced by drought, salt, cold and ABA. Therefore, our results indicated that PagbZIP1 might be expressed in response to abiotic stress through the ABA-mediated signaling pathway in poplar.

• Journal of Plant Biotechnology
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• v.46 no.3
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• pp.180-188
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• 2019

Auxin plays a crucial regulatory role in plant growth and development processes. Three major classes of auxin-responsive transcription factors controlled by the Auxin/indole-3-acetic acid (Aux/IAA), Gretchen Hagen 3 (GH3), and small auxin up RNA (SAUR) genes regulate auxin signaling. Aux/IAA, in particular, encodes short-lived nuclear proteins that accumulate rapidly in response to auxin signaling. In this study, we isolated a PagAux/IAA1 gene from poplar (Populus alba ${\times}$ P. glandulosa) and investigated its expression characteristics. The PagAux/IAA1 cDNA codes for putative 200 amino acids polypeptide containing four conserved domains and two nuclear localization signals (NLSs). Utilizing Southern blot analysis, we confirmed that a single copy of the PagAux/IAA1 gene was present in the poplar genome. The expression of this gene is specific to leaves and flowers of the poplar. PagAux/IAA1 expressed in the early exponential growth phase of cell-cultured in suspension. PagAux/IAA1 expression level reduced in drought and salt stress conditions, and the presence of plant hormones such as abscisic acid. However, expression enhanced in cold stress, cambial cell division, and presence of plant hormones such as gibberellic acid and jasmonic acid. Thus, these results suggest that PagAux/IAA1 participates in cold stress response as well as developmental processes in the poplar.

• Journal of Korean Society of Forest Science
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• v.71 no.1
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• pp.55-58
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• 1985

The anatomical diagnoses derived from the adventitious buds, the dimples, and their surroundings, which break out often in the Populus alba ${\times}$ P. glandulosa, were investigated by the light microscope. In the anatomical structure derived from the adventitious buds, the vessel seldom occured, the diameters of the cell were smaller and the wall thicknesses were thicker than those of the normal woods. The wood fibers around the adventitious buds were crooked, frequently had the septa, and the adjacent rays showed the multiple rows. The wood fibers of the dimples were extremely crooked from pith to the hark direction and the rays showed the multiple rows. The vessels in the line-like discoloration zone around the adventitious buds and the dimples formed the traumatic tyloses.

• Journal of Korean Society of Forest Science
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• v.79 no.1
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• pp.26-32
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• 1990

The relative aluminium tolerance of 5 Populus species (Populus davidiana, P. maximowiczii, P. nigra, P. alba ${\times}$ P. glandulosa, and P. nigra ${\times}$ P. maximowicizii) was evaluated on Murashige and Skoog medium with 5 levels of aluminium-EDTA concentration (0, 0.1, 0.2, 0.5, 1.0mM). The number of root initiation of 5 Populus species was significantly affected by the medium containing various levels of aluminium concentration. The native poplar, P. davidiana showed the highest aluminium tolerance among 5 species and even stimulated shoot and root growth on the medium containing at the low levels aluminium, 0.1 to 0.2 mM concentrations. The medium containing 1.0 mM aluminium inhibited root initiation from plantlets of all species except P. davidiana. Plantlets cultured on the medium with more than 0.5 mM aluminium exhibited retarded growth and abnormal leaf shape. P. nigra ${\times}$ P. maximowiczii exhibited significantly higher aluminium tolerance than its parental species. Silvicultural aspects associated with aluminium tolerance of Populus are also discussed.

• Journal of Korean Society of Forest Science
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• v.105 no.1
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• pp.103-107
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• 2016

This study aims to select the most appropriate poplar clones for planting on short rotation coppice poplar plantations in a riparian area. The research investigated biomass production, nitrogen and carbon absorption with 2-year-old poplar (Populus spp.) clones including P. euramericana clone Eco28, P. deltoides hybrid clone 97-18, and P. alba ${\times}$ P. glandulosa hybrid clone 72-30. The average number of stems per stump was five and P. euramericana clone Eco28 had the greatest average number of live stems per stump with 5.9. The average stem diameter was 23.2 mm, and P. deltoides hybrid clone 97-18 achieved the largest average diameter with 25.4 mm. The average annual above-ground biomass production of Populus deltoides hybrid clone 97-18 was 16.1 ton/ha/year, followed by P. alba ${\times}$ P. glandulosa hybrid clone 72-30 and P. euramericana clone Eco28, 12.3 and 5.4 ton/ha/year, respectively. The average annual nitrogen uptake of poplar clones was 46.5 kg/ha/year. P. alba ${\times}$ P. glandulosa hybrid clone 72-30 had the highest average, 63.1 kg/ha/year. The average of annual carbon absorption was estimated 5.3 ton/ha/year and Populus deltoides hybrid clone 97-18 showed the best results with 7.7 ton/ha/year. Based on the results given above, P. deltoides hybrid aspen clone 97-18 is considered as the most suitable poplar clones for wood biomass production on riparian areas.

• Journal of the Korean Wood Science and Technology
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• v.18 no.1
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• pp.15-23
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• 1990

Roughage feeds were produced from Hyun-aspen (Populus alba $\times$ P. glandulosa) by autohydrolysis. The objectives of this work were to find proper conditions for the treatment of Hyun-aspen by analyzing the compositional change and digestibility and to determine the content of sugar and phenol contained in liquor extracted by digestion. The results of this work were as follows: 1. The proper condition for autohydrolysis of Hyun-aspen chips were $160^{\circ}C$ and 30 minutes in an autoclave. The yield of potential feed from original material and digestibility were 91.3% and 38.9% respectively 2. According to cooking conditions the sugar concentration of extracted solution and the recovery rate of sugar were 0.1~2.5%, 0.3~14.6% respectively. The phenol concentration of extracted solution and the recovery rate of phenol were 0.1~0.3, 0.5~1.8% respectively.

• Journal of Plant Biotechnology
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• v.42 no.4
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• pp.356-363
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• 2015

In order to study genetic engineering in trees, the characterization of genes and promoters from trees is necessary. We isolated the promoter region (867 bp) of Pagns-LTP from poplar (P. alba ${\times}$ P. glandulosa) and characterized its activity in transgenic poplar plants using a ${\beta}$-glucuronidase (GUS) reporter gene. High-level expression of the Pagns-LTP transcript was found in poplar roots, while comparatively low-level expression was found in the young leaves. Pagns-LTP mRNA was not detected in other poplar tissues. Additionally, transgenic poplar plants that contained a Pagns-LTP promoter fused to a GUS reporter gene, displayed tissue-specific GUS enzyme activity localized in root tissue. In silico analysis of the Pagns-LTP promoter sequence reveals the presence of several cis-regulatory elements responsive to phytohormones, biotic and abiotic stresses, as well as those regulating tissue-specific expression. These results demonstrate that the Pagns-LTP promoter has tissue-specific expression activity in poplar roots and leaves that may be involved in organ development and plant resistance to various stresses. Therefore, we anticipate that the Pagns-LTP promoter would be a useful tool to genetically optimize woody plants for functional genomics.