• Journal of Plant Biology
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• v.16 no.1_2
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• pp.12-16
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• 1973

The inhibitory effect of Inula sesquiterpene lactones on the growth of Phaseolus vulgaris was tested and the abnormality of the stem organization caused by the lactones was also examined. The longitudinal growth of the young stem and the expansion of the young leaf were stopped by the application of the lactones. However, this inhibitory effect was appeared and strictly restricted within the treated area. So the young shoot was observed for possible bending as a result of the unilateral application of the lactones. When the application of the lactones into the medium, the growth of the plant was entirely repressed. However, the growth of shoot and re-initiation of root were started after the plant was transfered to the lactone free medium. And partial reversal of inhibition of the stem growth was achieved by the additions of gibberelline and the lactones.

• Korean Journal of Agricultural and Forest Meteorology
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• v.15 no.3
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• pp.191-200
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• 2013

This study was conducted to examine the geographic variation of bud phenology of Zelkova serrata provenances. Data were collected from Gangneung, Yilmsil, Hwaseong and Jinju plantations which were parts of the 6 provenance trials established by Korea Forest Research Institute in 2009. The 16 provenances were included in these trials. The starting date of bud burst and finishing date of leaf expansion were investigated from April to May every other day. The four geographic factors and fifteen climatic factors of the test sites and provenances were considered in this study. Canonical correlation analysis was conducted to examine the major factors affecting the bud phenology between test sites and provenances. The study results suggested that the major factors affecting the timing of bud burst were the differences of extremely high temperature (March-October), annual mean temperature, mean temperature (March-October), extremely high temperature (July-August) and mean humidity (June-October) between test site and provenance. The provenances with lower mean or high temperature than those of plantation showed the earlier bud burst and leaf expansion. It showed a typical north-south or low-high temperature cline. Finally, we discussed the implication of the tree breeding program of Z. serrata based on these results.

• Journal of Korean Society of Forest Science
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• v.95 no.1
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• pp.124-130
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• 2006

To explore the development of photoprotective mechanisms, chlorophyll a fluorescence, chlorophyll and carotenoid content and antioxidant enzyme activity in leaves were investigated at different vitality and leaf development stage of Alnus firma Sieb. et Zucc under tailing condition. The lowest maximum photochemical efficiency (Fv/Fm) in leaves of high- and low-vitality plants were observed at 12:00 pm and 2:00 pm, respectively, and the decrease of Fv/Fm in leaves of all plants were almost completely restored at 6:00 pm. Fv/Fm of full-expansion leaves was higher than that of emergence leaves at all measurement time. Chlorophyll, ${\beta}$-carotene and xanthophyll content in leaves of high-vitality plants and in full-expansion leaves were higher when compared to those of low-vitality plants and emergence leaves. Especially xanthophyll contents in both stage leaves of high-vitality plants were higher than 8.7 times and 18.8 times those of low-vitality plants. Only SOD activity was seen significant difference between leaf stage in leaves of high-vitality plants.

• Journal of Ginseng Research
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• v.40 no.2
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• pp.176-184
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• 2016

Background: Wild ginseng, Panax ginseng Meyer, is an endangered species of medicinal plants. In the present study, we analyzed variations within the ribosomal DNA (rDNA) cluster to gain insight into the genetic diversity of the Oriental ginseng, P. ginseng, at artificial plant cultivation. Methods: The roots of wild P. ginseng plants were sampled from a nonprotected natural population of the Russian Far East. The slides were prepared from leaf tissues using the squash technique for cytogenetic analysis. The 18S rDNA sequences were cloned and sequenced. The distribution of nucleotide diversity, recombination events, and interspecific phylogenies for the total 18S rDNA sequence data set was also examined. Results: In mesophyll cells, mononucleolar nuclei were estimated to be dominant (75.7%), while the remaining nuclei contained two to four nucleoli. Among the analyzed 18S rDNA clones, 20% were identical to the 18S rDNA sequence of P. ginseng from Japan, and other clones differed in one to six substitutions. The nucleotide polymorphism was more expressed at the positions 440-640 bp, and distributed in variable regions, expansion segments, and conservative elements of core structure. The phylogenetic analysis confirmed conspecificity of ginseng plants cultivated in different regions, with two fixed mutations between P. ginseng and other species. Conclusion: This study identified the evidences of the intragenomic nucleotide polymorphism in the 18S rDNA sequences of P. ginseng. These data suggest that, in cultivated plants, the observed genome instability may influence the synthesis of biologically active compounds, which are widely used in traditional medicine.

• Korean Journal of Medicinal Crop Science
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• v.9 no.1
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• pp.62-67
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• 2001

This study was carried out to investigate the optimum composition and concentration of medium for the acclimation of the shoots derived from bioreactor culture of Scrophularia buergeriana. Rooting and growth of the shoots cultured in bioreactor for 4 weeks were better on liquid full strength MS medium while one-tenth of MS medium was good for rooting and growth of the shoots cultured in bioreactor for 6 weeks. Leaf expansion was more effective in the shoots cultured for 6 weeks on solid MS medium than in those cultured for 4 weeks. No leaf expanded in liquid medium. Vitrification rate was higher in full strength solid MS medium than in half strength MS medium. It is concluded that acclimation of the shoots is more effective on the half strength solid MS medium containing 1.2% agar.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.44 no.1
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• pp.59-63
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• 1999

Yield and growth characteristics were compared for five rice cultivars; a new Tongil-type, so called "super-rice", Dasanbyeo, an old Tongil-type Milyang 23, two japonicas Dongjinbyeo and Ilpumbyeo, and a new plant type (NPT)line IR65600-27-1-2. The objective of this stusy was to clarify the high yielding capacity of Dasanbyeo in terms of growth characteristics. The average grain yield (9 t/ha) of Dasanbyeo was higher than that of Milyang 23 by ca. 9% that of japonicas by 20 to 30%, and that of NPT line by ca. 100%. The higher grain yield of Dasanbyeo was attributable not only to the greater dry matter production but also to the higher harvest index (HI). Dasanbyeo showed the greatest dry matter at harvest owing not only to the rapid leaf expan-sion at early growth stage and the resulting high LAI through the entire growth stage but also to the high NAR despite the high LAI. The rapid leaf expansion of Dasanbyeo at early growth stage seemed to be related in part to the profuse tillering capacity. HI was 0.53 in Dasanbyeo, 0,51 in Milyang 23, 0.41 in japonicas, and 0.35 in NPT line. Dasanbyeo was indebted for its higher HI to the relatively high grain filling ratio in spite of a much greater sink size than the other cultivars. Dasan had a greater source to sink ratio during grain ripening as measured by LAD/spikelet and dry matter production/spikelet which showed positove correlations with the grain ripening ratio. New plant type (NPT) line showed the lowest grain yield owing to the small sink size and the low grain filling ratio which seemed to have resulted from the abundant occurrence of weak-strength spikelets. The weak sink strength, in turn, seemed to have suppressed photosynthesis during the grain ripening stage.

• Molecules and Cells
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• v.28 no.1
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• pp.57-65
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• 2009

CDC48 is a member of the AAA ATPase superfamily. Yeast CDC48 and its mammalian homolog p97 are implicated in diverse cellular processes, including mitosis, membrane fusion, and ubiquitin-dependent protein degradation. However, the cellular functions of plant CDC48 proteins are largely unknown. In the present study, we performed virus-induced gene silencing (VIGS) screening and found that silencing of a gene encoding a tobacco CDC48 homolog, NgCDC48, resulted in severe abnormalities in leaf and shoot development in tobacco. Furthermore, transgenic tobacco plants (35S:anti-NgCDC48), in which the NgCDC48 gene was suppressed using the antisense RNA method, exhibited severely aberrant development of both vegetative and reproductive organs, resulting in arrested shoot and leaf growth and sterile flowers. Approximately 57-83% of 35S:anti-NgCDC48 plants failed to develop mature organs and died at early stage of development. Scanning electron microscopy showed that both adaxial and abaxial epidermal pavement cells in antisense transgenic leaves were significantly smaller and more numerous than those in wild type leaves. These results indicate that NgCDC48 is critically involved in cell growth and development of tobacco plants. An in vivo targeting experiment revealed that NgCDC48 resides in the endoplasmic reticulum (ER) in tobacco protoplasts. We consider the tantalizing possibility that CDC48-mediated degradation of an as-yet unidentified protein(s) in the ER might be a critical step for cell growth and expansion in tobacco leaves.

• The Plant Pathology Journal
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• v.29 no.3
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• pp.242-248
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• 2013

In the Northeast of Brazil, expansion of guava crops has been impaired by Meloidogyne enterolobii that causes root galls, leaf fall and plant death. Considering the fact that arbuscular mycorrhizal Fungi (AMF) improve plant growth giving protection against damages by plant pathogens, this work was carried out to select AMF efficient to increase production of guava seedlings and their tolerance to M. enterolobii. Seedlings of guava were inoculated with 200 spores of Gigaspora albida, Glomus etunicatum or Acaulospora longula and 55 days later with 4,000 eggs of M. enterolobii. The interactions between the AMF and M. enterolobii were assessed by measuring leaf number, aerial dry biomass, $CO_2$ evolution and arbuscular and total mycorrhizal colonization. In general, plant growth was improved by the treatments with A. longula or with G. albida. The presence of the nematode decreased arbuscular colonization and increased general enzymatic activity. Higher dehydrogenase activity occurred with the A. longula treatment and $CO_2$ evolution was higher in the control with the nematode. More spores and higher production of glomalin-related soil proteins were observed in the treatment with G. albida. The numbers of galls, egg masses and eggs were reduced in the presence of A. longula. Inoculation with this fungus benefitted plant growth and decreased nematode reproduction.

• The Korean Journal of Food And Nutrition
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• v.31 no.2
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• pp.229-235
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• 2018

Ramie (Boehmeria nivea M.) has been used for fiber materials in Korea traditionally, but in recent years, the concern with ramie leaves for the food industry such as tteok (a kind of Korean rice cake) industry has been increasing, so a study for eatable ramie is required for the expansion of ramie consumption. Moreover, the ramie varieties for the food industry are not established, so the natural species are cultivated in general; therefore, it is very important to select the ramie varieties for the food industry such as rice cakes, tea, beverage and so on. This study was undertaken to compare the physiochemical properties among 9 ramie lines selected in the Yeonggwang-gun Agricultural Technology Center to select the eatable ramie varieties for the food industry. The contents of the protein among 9 ramie lines was 6.21~7.56% and had the highest content in the YG55. The folic acid (folate) and vitamin C content had varying differences among the 9 lines; the content of folate showed $771.52{\sim}1,978.84{\mu}g%$, that of vitamin C showed 149.42~275.34 mg%. The ACE inhibitory activity appeared to be the highest in YG88 (21.5%) among the 9 ramie varieties tested.

• Journal of Life Science
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• v.7 no.2
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• pp.134-141
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• 1997

We have investigated several factors influencing adventitious shoot induction from the Populus deltodies bartr. leaf segments. To obtain in vitro materials, at first, stem segments from ex vivro were tested for axillary bud breaking on the five macronutrients levels of two differenr media. WPM was better both in bud breaking and leaf expansion than MS medium. The amount of NH$_{4}$NO$_{3}$ added in the medium did not seem to affect axillary bud breaking, significantly and subsequent shoot elongation from the stem segments of P. deltodies. However, other components in WPM might have played important roles in axillary bud breaking and shoot elongation. Regenerability from three sections (the distal, the middle and the base) of leaves cultured on WPM supplemented with TDZ and NAA combinations appeared to be different; middle and basal sections of leaves produced more organogenic sites than those of top section on WPM and those sesctions produced the highest ogranogenic sites on the same medium supplemented with 0.01 mg/l TDZ and 0.02mg.l NAA. Among 3 carbon sources tested for adventitious shoot elongation, fructose seemed to be stimulating the elongation of adventitious shoots. Sucrose and glucose added in the medium resulted in the necrosis which caused dying of adventitious shoots, eventually.