• Journal of Plant Biotechnology
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• v.29 no.4
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• pp.277-280
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• 2002

Acid phosphatase in the radish young plant showed optimal activity at pH 5.5. The activity of acid phosphatase was maintained longer during the ABA (0.5 mM) treatment than those in control, whereas that was similar to the treatment of NaCl (0.5 mM). But during the cold (4$^{\circ}C$) treatment, the activity of acid phosphatase was decreased dramatically compared to the control, which was maintained almost on a constant level and increased gradually during 6 days. It showed that acid phosphatase was in relation to the change of biochemical reaction, which plants were coped with cold, NaCl and ABA stress.

• The Korean Journal of Ecology
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• v.16 no.4
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• pp.377-395
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• 1993

Habitat types, community structure and population characteristics of Koelreuteria paniculata were investigated in Mt. Wolak, Chungbuk and Naesokdong, Daegu, which are natural habitats of the species in inland region of Korea, and its origin was discussed. Habitats of Koelreuteria paniculata were classified to 3 types: sand bar formed by the sands flooded in the course of flow of the mountain stream (Type 1). crevice on the rock bed within the mountain stream (Type 2) and crevice of the rock around the edge of mountain stream (Type 3). Most Koelreuteria paniculata communities in Mt. Wolak site were composed of 3 layers of subtree layer, shrub layer and herb layer and that of Daegu site was 4 layers including tree layer. In the floristic composition of the Koelreuteria paniculata community, plants occurring frequently in the wet and open site, such as Zelkova serrata and Fraxinus rhynchoph-vlla showed high frequency. Frequency distribution of diameter at ground surface of Koelreutrria paniculata showed reversed J-shaped type. It was supposed that expansion of Koelreuteria paniculata community in Mt. Wolak site might be accomplished by the flow of the stream. Many saplings capable of becoming a successor of mature trees in Daegu site in near degenerating phase were established on the forest floor of the Koelreuteria paniculata community. From this result, it was supposed that these saplings originated from the seeds dispersed from a seed tree might form the Koelreuteria paniculata community of the next generation. On the other hand, the origin of Koelreutevia paniculata in inland sites was explained by two hypotheses: the one was that Koelreuteria paniculata might be transplanted by human and the other was that the present site might be native habitat of the community.

• Journal of Plant Biology
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• v.35 no.1
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• pp.91-95
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• 1992

Changes of contents of reducing sugar and sucrose and activities of sucrose-phosphate synthase, sucrose synthease and invertase from the leaves of barley (Hordeum vulgare L. cv. Chalssal) seedlings grown at $4^{\circ}C$ were investigated, and the property of acid invertase were also examined. In the seedlings grown at $4^{\circ}C$ for 3 days, the contents of reducing sugar and sucrose were increased to 1.3 and 2.4 times, respectively. Activity of acid invertase was decreased markedly by cold treatment while the activities of sucrosephosphate synthase, sucrose synthase, and alkaline invertase were not changed. In acid phosphatase purified partially by ammonium sulfate fractionation and DEAE-Sephacel column chromatography, the $K_m$ value for sucrose was 9.5 mM and the optimum pH and temperature was 5.5 and $35^{\circ}C$ respectively. This enzyme was supposed to be ${\beta}-fructosidase$ by studies on the substrate specificity and the molecular weight was estimated to be 63 Kd by Sephadex G-200 gel chromatography.graphy.

• Korean Journal of Environmental Agriculture
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• v.13 no.2
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• pp.175-182
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• 1994

The experiment was performed to investigate the effects of simulated acid rain of several pH levels (2.0, 3.0, 4.0, and 5.0) on growth, injury, pigment compositions and leaf surface morphology of the seedlings of Amaranthus tricolor L. by foliar application. The growth of the tops and roots was markedly retarded below pH 3.0 and speck spots appeared on the leaf. Seven different peaks were detected by the absorption spectra of pigments of the leaf. But cv. Early splendor did not show the peaks at 473nm and 535nm, and nor did cv. Tricolor show the peaks at 476nm and 546nm. The pigment composition of leaves was affected by strong acid rain. As pH levels decreased, chlorophyll content increased. Leaf surface was eroded by acid rain, and leaf surface tissues were broken down and collapsed at the lower pH levels.

• Journal of Plant Biology
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• v.38 no.4
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• pp.399-407
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• 1995

The effects of 0.5 and 1.0 ppm of ozone on the developing chloroplast of barley (Hordeum vulgare L) seedling during greening were investigated by PSI and II activities, chlorophyll fluorescence, and the contents of chlorophyll. Etiolated barley seedling was treated 0.5 and 1.0 ppm ozone for the first 4 h during greening. In 24 h greening experiment, the contents of chlorophyll were decreased by increasing ozone concentration from 0.5 ppm to 1.0 ppm. In 24 h greening experiment, Fo, Fv, Fm and qE were greatly decreased as the concentration of ozone was increased, but those were not considerably decreased in 48 h greening experiment. In another experiment, the developing barley seedling was treated with 0.5 and 1.0 ppm ozone for the last 4 h during greening period, which was 24 h or 48 h. In both experiments the PS II activity was decreased as the concentration of ozone was increased, but not in PS I activity. Fv, Fm and Fv/Fo were also decreased as the concentration of ozone was increased. qP and qR were strikingly decreased as the concentration of ozone was increased in both experiments.iments.

• Magazine of the Korea Institute for Structural Maintenance and Inspection
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• v.17 no.2
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• pp.36-44
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• 2013

• The Korean Journal of Ecology
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• v.16 no.4
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• pp.501-514
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• 1993

In order to study the ecotypic variation of Robinia pseudo-acacza L. distributed in southern area of Korean peninsula, 15 local populations(Daejin, Sokcho, Kangneung, Mt. Surak, Hongcheon, Kwangneung, Namhansanseong, Chungju, Yesan, Andong, Jeonju, Dalseong, Changweon, Mokpo and Wando), located from $34^{\circ}18'N\;to\;38^{\circ}36'N$, were selected based on their latitudes and geographical distances. Seeds of these populations were collected and their germination and growth of seedlings were investigated. The optimum temperature of seed germination tends to decrease with ascending latitudes. The optimum temperatures of local populations were classified into three types: the north central type of $25^{\circ}C$(Daejin, Sokcho, Kangneung, Mt. Surak, Hongcheon, Kwangneung), the south central type of $30^{\circ}C$(Narnhansanseong. Chungju, Yesan, Andong, Jeonju), and the southern type of $35^{\circ}C$(Dalseong, Changweon, Mokpo, Wando). The optimum temperature for the growth of seedlings was $25^{\circ}C$ for all populations. The populations were also classified into three types : north central type, south central type and southern type based on the ranking on the growth of seedlings at 5 different temperatures of 15, 20, 25, 30 and $35^{\circ}C$, and the results of seedling growth showed similar patterns to those of the seed germination.

• Korean Journal of Plant Tissue Culture
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• v.21 no.1
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• pp.15-22
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• 1994

To understand the molecular mechanism of hardening process in somatic embryo development and artificial seed germination in celery (Apium graveolens L.), the changes of protein synthesis by ABA or cold teatment at early globular stage were examined. Protein content and nitrate reductase activity in ABA- or cold-treated somatic embryo and seedlings were higher than that in unheated ones. The protein content and nitrate reductase activity were more prominent in somatic embryos than in seedlings. From two-dimensional electrophoresis, several protein spots specific to ABA or cold treatment were identified: 30 KD, 32 KD, 171 KD and 205 KD at heart-shaped stage; and 29 KD, 33 KD, 37 KD, 38 KD, 41 KD, 55 KD, 66 KD, and 110 KD at cotyledonary stage were the most specifically synthesized However the synthesis of certain polypeptides were repressed at heart-shaped or cotyledonary stage: 42 KD, 44 KD, 59 KD, 64 KD, 101 KD, 104 KD, and 190 KD at heart-shaped stage; and 29 KD and 116 KD at cotyledonary stage. The protein pattern changes by ABA or cold treatment occurred simultaneously and mainly in acid-soluble proteins during somatic embryo development and artificial seed germination. Therefore it is suggested that the metabolic changes for adaptation to environmental change occur during somatic embryo development and the germination and growth of seedling from embryo.

• Korean Journal of Plant Tissue Culture
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• v.28 no.2
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• pp.103-108
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• 2001

The in vitro plantlets of cassava (Manihot esculenta Crantz cv. MColl 22) could be regenerated from nodal explant cultures in a liquid MS basal medium containing 0.01 mg/L zeatin for 2 weeks. The plantlets of 1.5∼2.5 cm in shoot length were transplanted to a glass bottle containing fine sand and acclimated under non-sterile conditions after excising their intact roots by: 1) prune leaving roots base of 1∼1.5 cm; 2) complete removal of roots; and 3) cutting off the rooting zone. The majority of in vitro-formed intact roots continued growth after transferred to soil, and all of the damaged roots stopped further growth. The plantlets with excised roots began to develop new roots within 7∼10 days after being transferred to a glass bottle, and a few of the pruned roots developed lateral roots from the remaining portion. Pruning and removal of in vitro roots resulted in a high survival rate (>87%), and did not significantly affect ex vitro root regeneration and acclimation, but the plantlets in which the rooting zone had been cut-off showed 73% survival rate. Pruning or removal of in vitro roots before transfer of plantlets is recommended for useful method of commercial micropropagation because of easier handling and high survival rate of plantlets.

• Korean Journal of Plant Tissue Culture
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• v.27 no.3
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• pp.185-189
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• 2000

For the micropropagation, node explants of cassava were cultured in liquid MS medium with various concentrations of cytokinins on a rotary shaker (100 rpm) for 2 weeks. The adventitious roots and shoots from the explants were differentiated more efficiently in liquid medium than in solid. But root formation was not inhibited in medium with BAP and kinetin at low concentration (＞0.05 mg 1/sup -1/), while in medium added with BAP and zeatin at high level (＜0.25 mg 1/sup -1/), it was inhibited by callus forming on cut end of the cuttings. However, all of plantlets grown in liquid medium for more than 2 weeks showed symptoms of hyperhydricity. The plantlets grown in liquid medium were transferred into culture bottles filled with fine sand or artificial soil (pitmoss：perlite：vermiculite, 1：1：1 v/v) wetted with half strength of Knop's solution. After transplanted to culture bottles, some of vitriscent leaves were defoliated and new leaves were normally formed from shoot apex. Most of plantlets (＞95%) were hardened-off successfully only in culture bottles with fine sand, and grew into 3-5 cm seedlings possessing 4-6 nodes after 4 weeks. Thus, the mass propagation of cassava on medium containing cytokinin could be established based on the suspension culture using node explants.