• Molecules and Cells
• /
• v.45 no.10
• /
• pp.695-701
• /
• 2022

Homeostatic regulation of meristematic stem cells accomplished by maintaining a balance between stem cell self-renewal and differentiation is critical for proper plant growth and development. The quiescent center (QC) regulates root apical meristem homeostasis by maintaining stem cell fate during plant root development. Cell cycle checkpoints, such as anaphase promoting complex/cyclosome/cell cycle switch 52 A2 (APC/C^CCS52A2), strictly control the low proliferation rate of QC cells. Although APC/C^CCS52A2 plays a critical role in maintaining QC cell division, the molecular mechanism that regulates its activity remains largely unknown. Here, we identified SCF^FBS1, a ubiquitin E3 ligase, as a key regulator of QC cell division through the direct proteolysis of CCS52A2. FBS1 activity is positively associated with QC cell division and CCS52A2 proteolysis. FBS1 overexpression or ccs52a2-1 knockout consistently resulted in abnormal root development, characterized by root growth inhibition and low mitotic activity in the meristematic zone. Loss-of-function mutation of FBS1, on the other hand, resulted in low QC cell division, extremely low WOX5 expression, and rapid root growth. The 26S proteasome-mediated degradation of CCS52A2 was facilitated by its direct interaction with FBS1. The FBS1 genetically interacted with APC/C^CCS52A2-ERF115-PSKR1 signaling module for QC division. Thus, our findings establish SCF^FBS1-mediated CCS52A2 proteolysis as the molecular mechanism for controlling QC cell division in plants.

• Journal of the Korean Society of Tobacco Science
• /
• v.11 no.2
• /
• pp.197-202
• /
• 1989

This experiment was conducted to investigate the effect of growth medium in pots composed of upland soil(S), rice straw manure(M), carbonated rice hull(CRH), and their mixture on growth of tobacco cv. NC 82. The growth of shoot and root was vigorous in order of medium S+M+CRH>M>CRH>S. In M+S medium, root growth in the part of manure was superior to upland soil. But root growth of upland soil part in M+S plot was more vigorous than that in upland soil only. It is possibly due to be influenced by manure in M+S plot. Total length and weight of root, number of roots, and especially for development of adventitious root were closely related to shoot growth. Roots grown in upland soil part was brownish gray in color, while the roots in manure part was milky white. The milky white colored roots had longer life than others. It was concluded that root zone environments derived from several media in pots closely related to shoot growth and disease tolerance of tobacco plant.

• Korean Journal of Plant Tissue Culture
• /
• v.27 no.4
• /
• pp.309-315
• /
• 2000

Panax ginseng is an important medicinal plant that has been used worldwide for geriatric, tonic, stomachic, and aphrodisiac treatments. Ginsenosides contained in the ginseng root are the main substances having active functions for human body. The price of ginseng is very expensive due to a complex process of cultivation, and the yield of ginseng is limited, which cannot meet the demand of the increasing market. Researchers have applied plant biotechnology to solve the problems but there are still things to be determined towards ginsenoside production by large-scale adventitious root culture. In this experiment, 5 to 20 liter bioreactors were employed to determine optimal conditions for adventitious root culture and ginsenoside production of Panax gineng. Callus was induced from the ginseng root on MS agar medium containing 1.0 mg. $L^{-1}$ 2,4-D and 0.1 mg. $L^{-1}$ kinetin. Then the callus was cultured on MS agar medium supplemented with 2.0 mg. $L^{-1}$ IBA, 0.1 mg. $L^{-1}$ kinetin, and 30 g. $L^{-1}$ to induce adventitious roots. The maximum root growth and ginsenoside production were obtained in 1/2 MS medium. 2.0 mg. $L^{-1}$ naphthalene acetic acid resulted in greater root growth than 2.0 mg $L^{-1}$ indole-3-butyric acid. Ginsenoside content increased with 2.0 mg. $L^{-1}$ benzyl adenin or kinetin. High concentrations of benzyl adenin (above 3.0 mg. $L^{-1}$ ) decreased the adventitious root growth and ginsenoside productivity. N $H_{4}$$^{+}$ inhibited the ginsenoside accumulation, while high concentrations of $K^{+}$, $Mg_{2}$$^{+}$, and $Ca_{2}$$^{+}$ increased it. N $H_{4}$$^{+}$ at 0.5 and 1.0 times of the normal amount in 3/4 SH medium resulted in the greatest biomass increase, but the highest ginsenoside productivity was obtained when N $O_{3}$$^{-}$ was used as the sole nitrogen source in the medium. Most microelements at high concentrations in the medium inhibited the root growth, but high concentrations of MnS $O_4$enhanced the root growth. Root dry weight increased with increasing sucrose concentrations up to 50 g. $L^{-1}$ , but decreased from 70 g $L^{-1}$ Ginsenoside productivity was maximized at the range of 20 to 30 g. $L^{-1}$ sucrose. In the experiment on bioreactor types, cone and balloon types were determined to be favorable for both adventitious root growth and ginsenoside production. Jasmonic acid was effective for increasing ginsenoside contents and Rb group ginsenosides mainly increased. These results could be employed in commercial scale bioreactor cultures of Panax ginseng.x ginseng.

• KOREAN JOURNAL OF CROP SCIENCE
• /
• v.27 no.3
• /
• pp.218-222
• /
• 1982

It has been ascertained by a few researchers that soil salinities of the saline paddy fields have some effects upon the root development of the rice plants. But much is not known about the root formations of the rice plants in different varieties cultivated at the saline paddy field. Therefore this experiments were conducted to study the salinity tolerance of rice plants via variety test. Tested varieties were Akibare, Jinheung, Milyang #30, Josaeng Tongil, Suweon #264 and Suweon #287. And testing methods were cultivation experiment at the saline paddy field and leaf-cutting method at the laboratory. The results of cultivation experiment showed Milyang #30 and Josaeng Tongil were superior to others in root formation, and those of leaf-cutting method revealed that Josaeng Tongil and Mi1yang #30 were also superior to others in root formation and root length.

• Korean Journal of Plant Resources
• /
• v.31 no.6
• /
• pp.719-724
• /
• 2018

Methicillin-resistant Staphylococcus aureus (MRSA) is a bacterium responsible for a number of infections in humans that are difficult to treat, and as a result, is a substantial contributor to morbidity and mortality. In the present study, in search of natural products capable of inhibiting this multidrug-resistant bacterium, we investigated the antimicrobial activity of Lysimachia clethroides Duby root. The antibacterial activities of EtOH extract of Lysimachia clethroides Duby root and its n-hexane, EtOAc, n-BuOH and water fractions were evaluated against 15 strains of methicillin-resistant staphylococcus aureus (MRSA) and 1 standard methicillin-susceptible S. aureus (MSSA) strain by using the minimal inhibitory concentrations (MICs) assay, colorimetric assay using MTT test, checkerboard dilution test. Antimicrobial activity of n-hexane fraction of Lysimachia clethroides Duby root was remarkable. Against the 16 strains, the minimum inhibitory concentrations (MICs) were in the range of $31.25-62.5{\mu}g/ml$ and FICI values for n-hexane fraction of Lysimachia clethroides Duby root+AM and n-hexane fraction of Lysimachia clethroides Duby root+OX were checkerboard method performed using the MRSA, MSSA and one clinical isolate strains via MICI 0.12-1 and 0.25-0.75, showing the increase of synergistic effect. When combined together, these antibiotic effects were dramatically increased. These effective combinations could be new promising agents in the management of MRSA.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
• /
• v.34 no.6
• /
• pp.657-664
• /
• 2008

Purposes: The aim of this study was to evaluate pulp healing, periodontal healing, root development of autotransplantation of immature third molars and show its viability in treatment of early loss of tooth in young patients Materials and methods: In this article we performed a retrospective study with 41 transplanted teeth in 36 patients. The Mean age at the time of surgery was 17 years(range $13{\sim}24$ years) and mean postoperative follow up period was 2.4 years(range $1{\sim}6$ years) We evaluated the survival rate, pulp healing, periodontal healing, root development of the above teeth Results: At the last examination 40 teeth among 41 transplants were still present so survival rate was 97.6%. The pulpal healing was found in 38 teeth of 41 transplants. The periodontal healing was found in 38 transplants. The continuous root development was seen in 38 transplants. Conclusions: From the above results, the autotransplantation of immature third molars was found to be a useful and reliable treatment method for early loss of teeth in adolescents and young adults.

• The Plant Pathology Journal
• /
• v.36 no.3
• /
• pp.244-254
• /
• 2020

Gom-chwi (Ligularia fischeri) is severely infected with Phytophthora drechsleri, the causal organism of Phytophthora root rot, an economically important crop disease that needs management throughout the cultivation period. In the present study, Phytophthora root rot was controlled by using bacterial isolates from rhizosphere soils collected from various plants and screened for antagonistic activity against P. drechsleri. A total of 172 bacterial strains were isolated, of which, 49 strains showed antagonistic activities by dual culture assay. In the seedling assay, six out of the 49 strains showed a predominant effect on suppressing P. drechsleri. Among the six strains, the ObRS-5 strain showed remarkable against P. drechsleri when treated with seed dipping or soil drenching. The ObRS-5 strain was identified as Enterobacter asburiae based on 16S ribosomal RNA gene sequences analysis. The bacterial cells of E. asburiae ObRS-5 significantly suppressed sporangium formation and zoospore germination in P. drechsleri by 87.4% and 66.7%, respectively. In addition, culture filtrate of E. asburiae ObRS-5 also significantly inhibited sporangium formation and zoospore germination by 97.0% and 67.6%, respectively. Soil drenched bacterial cells, filtrate, and culture solution of E. asburiae ObRS-5 effectively suppressed Phytophthora root rot by 63.2%, 57.9%, and 81.1%, respectively. Thus, E. asburiae ObRS-5 could be used as a potential agent for the biological control of Phytophthora root rot infecting gom-chwi.

• Proceedings of the Korean Society of Crop Science Conference
• /
• 2022.10a
• /
• pp.54-54
• /
• 2022

Recently, as one of the major problems in the quality of sweetpotato, occurrence of thin and long fibrous tissues in storage root acts as a negative factor when consumers eat sweetpotato. In this study, the fiber content was compared according to the cultivation period in storage roots of 'Sodammi' and 'Hopungmi', which were newly bred and developed, and in that of 'Hogammi', which contains a lot of fibrous tissues. To isolate of fiber from storage root, the Association Official Analytical Chemists (AOAC) method was applied for quantifying fiber present in storage root of sweetpotato. The fiber contents isolated by this method is calculated by converting the weight of the storage root. The fiber content was measured every 20 days from 60 to 120 days after planting. As a result of this study, the lowest amount of fiber was 'Hopungmi' (70~140 mg/100 g), and the highest amount of fiber was observed in 'Hogammi' (115~223 mg/100 g). 'Sodammi' showed an intermediate level (104~149 mg/100 g) between the fiber content of 'Hopungmi' and 'Hogammi'. The fiber contents of 'Hopungmi' was 39% lower than that of 'Hogammi'. As the increased cultivation periods, the fiber contents showed a tendency to decrease. In the future research, the length, thickness, and fiber contents will be investigated to compare the degree of taste inhibition.

• Korean Journal of Medicinal Crop Science
• /
• v.22 no.2
• /
• pp.154-159
• /
• 2014

This study was carried out in order to investigate the early growth and root development characteristics of Atractylodes japonica container seedling. Experiment was performed by light intensity (100%, 60%, 25% and 10% of full sunlight). Height was surveyed well under 25% of full sunlight (overall 11.013.0%). Root collar diameter was the highest in the full sunlight (7.52 mm). It was the highest fresh weight (1.52 g, 0.92 g, 0.90 g and 3.34 g) under 25% of full sunlight, root dry weight was getting higher in the higher light level and the highest in the full sunlight (0.13 g). Total root length, root project area, root surface area and root volume were the highest under 25% of full sunlight (434.7 cm, $17.4cm^2$, $54.7cm^2$, $0.55cm^3$, respectively) and the lowest under 10% of full sunlight. As a result of surveying the whole experiment, A. japonica is judged nicely by maintaining 25% of full sunlight, excepting 10% of full sunlight. And light levels during the early growth are overly important to improve early growth.

• KOREAN JOURNAL OF CROP SCIENCE
• /
• v.42 no.2
• /
• pp.146-152
• /
• 1997

Development of shoot and root, leaf water potential and photosynthetic rate affected by water stress in early growing stage of tobacco were surveyed to interpret stress response in terms of plant physiological and agricultural aspects. The growth of shoot and root was highly suppressed by water stress and the difference in dry weight by rewatering was smaller in root than in shoot. The total root length was highly decreased by water stress and the lengths of root for water stress and non-stress were 74m and 84m, respectively, after rewatering. The root growth treated by water stress was increased between 2nd and 3rd day after treatment indicating that temporary water stress at early growing stage might have increased of root zone activity for early growth stage. The leaf water potentials were decreased to -7.63MPa, -9.47MPa, -11.89MPa, -13MPa at the 2nd, 3rd, 4th and 5th day by water stress. The relative water contents were 75%, 62% and 57% at the 3rd, 4th and 5th day after treatment. Photosynthesis was reduced largely by water stress. The photosynthetic rate after treatment at 2nd day and 3rd day was dropped to 18.15$\mu$mol. $CO_2$/$m^2$ㆍsec$^{-1}$ and 9.35$\mu$mol. $CO_2$/$m^2$ㆍsec$^{-1}$. It was never recovered to the normal, even after rewatering. Stomatal conductance had been reduced since 2nd day after treatment and increased after rewatering.