• Molecules and Cells
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• v.41 no.10
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• pp.923-932
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• 2018

Ethylene regulates numerous aspects of plant growth and development. Multiple external and internal factors coordinate ethylene production in plant tissues. Transcriptional and post-translational regulations of ACC synthases (ACSs), which are key enzymes mediating a rate-limiting step in ethylene biosynthesis have been well characterized. However, the regulation and physiological roles of ACC oxidases (ACOs) that catalyze the final step of ethylene biosynthesis are largely unknown in Arabidopsis. Here, we show that Arabidopsis ACO1 exhibits a tissue-specific expression pattern that is regulated by multiple signals, and plays roles in the lateral root development in Arabidopsis. Histochemical analysis of the ACO1 promoter indicated that ACO1 expression was largely modulated by light and plant hormones in a tissue-specific manner. We demonstrated that point mutations in two E-box motifs on the ACO1 promoter reduce the light-regulated expression patterns of ACO1. The aco1-1 mutant showed reduced ethylene production in root tips compared to wild-type. In addition, aco1-1 displayed altered lateral root formation. Our results suggest that Arabidopsis ACO1 integrates various signals into the ethylene biosynthesis that is required for ACO1's intrinsic roles in root physiology.

• Restorative Dentistry and Endodontics
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• v.41 no.1
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• pp.29-36
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• 2016

Objectives: The purpose of this study was to assess the ability of two new calcium silicate-based pulp-capping materials (Biodentine and BioAggregate) to induce healing in a rat pulp injury model and to compare them with mineral trioxide aggregate (MTA). Materials and Methods: Eighteen rats were anesthetized, cavities were prepared and the pulp was capped with either of ProRoot MTA, Biodentine, or BioAggregate. The specimens were scanned using a high-resolution micro-computed tomography (micro-CT) system and were prepared and evaluated histologically and immunohistochemically using dentin sialoprotein (DSP). Results: On micro-CT analysis, the ProRoot MTA and Biodentine groups showed significantly thicker hard tissue formation (p < 0.05). On H&E staining, ProRoot MTA showed complete dentin bridge formation with normal pulpal histology. In the Biodentine and BioAggregate groups, a thick, homogeneous hard tissue barrier was observed. The ProRoot MTA specimens showed strong immunopositive reaction for DSP. Conclusions: Our results suggest that calcium silicate-based pulp-capping materials induce favorable effects on reparative processes during vital pulp therapy and that both Biodentine and BioAggregate could be considered as alternatives to ProRoot MTA.

• Journal of Microbiology and Biotechnology
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• v.33 no.10
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• pp.1299-1308
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• 2023

Carya cathayensis is an important economic nut tree that is endemic to eastern China. As such, outbreaks of root rot disease in C. cathayensis result in reduced yields and serious economic losses. Moreover, while soil bacterial communities play a crucial role in plant health and are associated with plant disease outbreaks, their diversity and composition in C. cathayensis are not clearly understood. In this study, Proteobacteria, Acidobacteria, and Actinobacteria were found to be the most dominant bacterial communities (accounting for approximately 80.32% of the total) in the root tissue, rhizosphere soil, and bulk soil of healthy C. cathayensis specimens. Further analysis revealed the abundance of genera belonging to Proteobacteria, namely, Acidibacter, Bradyrhizobium, Paraburkholderia, Sphaerotilus, and Steroidobacter, was higher in the root tissues of healthy C. cathayensis specimens than in those of diseased and dead trees. In addition, the abundance of four genera belonging to Actinobacteria, namely, Actinoallomurus, Actinomadura, Actinocrinis, and Gaiella, was significantly higher in the root tissues of healthy C. cathayensis specimens than in those of diseased and dead trees. Altogether, these results suggest that disruption in the balance of these bacterial communities may be associated with the development of root rot in C. cathayensis, and further, our study provides theoretical guidance for the isolation and control of pathogens and diseases related to this important tree species.

• Journal of Periodontal and Implant Science
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• v.25 no.1
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• pp.24-34
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• 1995

The purpose of this study was to compare effects of demineralization of citric acid and tetracycline HCI on periodontally involved root surface. Twelve periodontally involved single rooted teeth were used. After scaling and root planing, root conditioning with citric acid and tetracycline HCI were carried and the teeth were processed scanning electron microscopic observation.The results were as follows: The scaled root surface was covered by much debris and calculus. The effect of demineralization of citric acid and tetracycline HCI was more reduced on scaling group than root planing group, because of hypermineralization of cementum surface and demineralization effect on root surface of tetracycline HCI showed tendency to reduction. The root planed group displayed more smooth root surface than scaling group, the surface was covered by smear layer, thus no exposure of dentinal tubule opening and collagen fiber, especially after root planing, citric acid and tetracycline HCl treated group showed exposure of dentinal tubule and collagen fiber, thus it was thought that new connective tissue attachment could be acquired.

• Restorative Dentistry and Endodontics
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• v.27 no.4
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• pp.355-362
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• 2002

One fifth dilution of formocresol is usually used for pulpotomy of the primary teeth and emergency pulpotomy of the permanent teeth. However the use of formaldehyde has been subjected to criticism because it may be absorbed into the blood stream and become distributed systemically, it nay also alter the pulp tissue rendering it immunologically active, and have carcinogenic potential. Recently Depulpin$^{\circledR}$(VoCo., Germany) gains popularity as a devitalizing agent during root canal therapy in spite of high concentration of 49 % paraformaldehyde because it facilitate devitalization of pulp and make root canal therapy easier But there have been not enough publications about the reaction of pulp and periapical tissue caused by Depulpin. This study was performed to evaluate the histological changes in pulp and periapical tissue of rats after pulpotomy using formocresol and Depulpin and to elucidate the toxic effects of these agents. Thirty six Sprague-Dawley rats were anesthetized by intraperitoneal injection of ketamine Maxillary first molar teeth were used for pulpotomy with formocresol and Depulpin. Rats were sacrificed after 2 days, 4 days, 1 week, 2 weeks, 3 weeks and 4 weeks respectively. Specimens were histologically observed by light microscope changes in pulp and periapical tissue. The obtained results were as follows. 1. Formocresol group A zone of fixed tissue. in which odontoblasts could clearly be defined, was present directly underneath the pulpotomy dressing in almost all teeth of this group. This was followed by an area of necrotic tissue which resembled dried out fibrous tissue with no cellular detail except some pyknotic nuclei. In the specimens of after 2 days, 4 days, 1 week, 2 weeks in which vital tissue was present, it was separated from the fibrous area by a zone of inflammation. In the specimens of after 3 weeks and after 4 weeks, inflammatory infiltrate was in the periodontal ligament adjacent to the apical foramina of the teeth. 2. Depulpin$^{\circledR}$ group The area of necrotic tissue which had no cells and fibers, was present adjacent to the dressing. This was followed by dried out fibrous tissue with no cellular details except some pyknotic nuclei, A short stump of vital pulp with odontoblasts was present at the end of the canal after 2 days. Inflammatory infiltrate was in the periodontal ligament after 4 days and after 1week. Severe root resolution and necrosis of periapical tissue opposite the root resorption site were defined after 2 weeks and after 3 weeks. Periapical lesion which consist of necrotic tissue surrounded by a fibrous connective wall, was found after 4 weeks. The results indicated that Depulpin can cause more adverse reaction to the dental pulp and periapical tissue than formocresol, and further studies are needed for its clinical use with safety.

• Korean Journal of Plant Resources
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• v.24 no.5
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• pp.591-598
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• 2011

This study was conducted to establish the tissue culture system for Atractylodes plant which is most frequently used in oriental medicine. Root and auxiliary bud of Dachul cv., which is Atractylodes hybrid (A. macrocephala x A. japonica), were used as target tissues for in vitro culture. In root culture, callus induction rate was higher in the treatment of BAP combined with NAA than others, however, 2-iP was more effective for callus proliferation and root induction. Although calli were effectively induced from the root and proliferated in lower concentration of cytokinin combined with higher auxin, root tissue was inappropriate for shoot regeneration. For plant regeneration with axillary bud, BAP combined with NAA was more effective than 2-iP with NAA or IBA. Number of regenerated plant per bud was 3.8, which was highest, and stem diameters was shown as 5.0mm under the conditions of 1 mg/L BAP combined with 1 mg/L NAA. Although, plant height was tend to be higher in 2-iP than BAP, number of the regenerated plant was lower via versus. Furthermore, root proliferation of regenerated plant was more effective in higher concentration of sucrose (7%) than in lower concentration (3%). In results, auxiliary bud was an efficient target tissue for producing regenerated plant of Atractylodes under the conditions of 1 mg/L BAP combined with 1 mg/L NAA and higher concentration of sucrose was effective for root proliferation of regenerated plants.

• Horticultural Science & Technology
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• v.29 no.2
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• pp.95-101
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• 2011

The influence of physicochemical properties of root substrates on the growth of mother plants and occurrence of daughter plants in 'Seolhyang' strawberry propagation were investigated through plastic bag cultivation. Six different formulations of root substrates were coir dust + perlite (5:5, A), coir dust + perlite (6:4, B), coir dust + perlite (7:3, C), coir dust + coconut chip (7:3, D), coir dust + coconut chip (6:4, E), and peatmoss + vermiculite (5:5, v/v; F). The total porosities (TP) and container capacities (CC) of all root substrates were higher than 85% and 55%, respectively, indicating that all substrates were in the acceptable range. But the TP and CC of F substrate were 91.5% and 60%, respectively, which were the highest among the root substrates tested. In the soil chemical properties analyzed before planting and after harvesting of 'Seolhyang' strawberry mother plants, the root substrates of A, B, C, and F had higher electrical conductivity and $NO_3$-N concentrations than those of D and F. The root substrates of A, B, C, and F had heavier runner fresh and dry weights, longer runner lengths, and more daughter plant occurrence than those of D and F. The treatment F had higher tissue N content than any other treatments at 120 days after the transplanting of 'Seolhyang' strawberry and statistical differences were not observed among remained 5 substrates. The treatment of F also had the higher tissue contents of other nutrients except N analyzed at 120 days after transplanting. These results indicated that soil chemical properties rather than physical properties severely influenced the growth of runners and occurrence of daughter plants.

• Applied Microscopy
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• v.41 no.1
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• pp.55-60
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• 2011

Reduced plants of Spirodela polyrhiza consisting only of fronds, stalks and roots form turions during dormancy. In development, mature fronds produce offspring fronds by vegetative reproduction, and turions arise laterally from the mother frond before dormancy. The turion primordium is derived from the frond, while the frond primordium forms within the turion tissue. In the present study, cellular features, especially those of the plastids, of the above four tissue types have been examined and compared using electron microscopy. Proplastids, found to be numerous in the frond and turion primordia, differentiated into chloroplasts rapidly upon growth. The proplastids were small and the thylakoidal membrane system was rudimentary, howerver the chloroplasts exhibited variation by cell type. Chloroplasts were found within cells of the frond, stalk and root tissue. The thylakoidal membrane system, which formed grana stacks, was moderately developed within frond chloroplasts, while only a few were present in those of the stalk and root cortical cells. One to two starch grains were accumulated within frond chloroplasts, but little to none were found in stalk and root cortical chloroplasts. Contrary to other types of root chloroplasts, those found in the root cap cells developed chloroplasts similar to the frond type. Unlike proplastids of the turion primordia, numerous large amyloplasts occupied most of the turion cell volume. Moreover, the turion cell produced quite large starch grain (s) within the amyloplasts. Accumulation of the starch grains continued until they occupied the most of the stroma and in some cases, individual starch grains reached up to $9.0{\mu}m$ in length. None to little, if any, thylakoidal or internal membranous systems were seldom detected in these amyloplasts. Although the degree of cellular and tissue differentiation was rather minimal within their reduced body, the functional differentiation of Spirodela polyrhiza was very efficient, as is the case in other advanced species.

• Journal of Periodontal and Implant Science
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• v.27 no.3
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• pp.621-631
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• 1997

To verify the effect of subgingival calculus on the periodontal tissues in periodontitis and the effectiveness of supragingival scaling to remove the calculus, 30 teeth from healthy group (Probing pocket depth:$PPD{\leq}mm$: HP group), 15 teeth from moderate group ($4{\leq}PD<7mm$:MP group), 30 teeth from advanced group (PPD>7mm: AP group) were selected and supragingival scaling was performed before extraction of all experimental teeth. After careful extraction, the teeth were cleaned with saline and disclosed with toluidine blue and carefully examined the relationship and distance between the calculus attached on the root surface and periodontal tissues. As a result, it was; 1. The calculus was not discovered on the root surface of teeth in HP group, but was in MP and AP group, mostly on interproximal surface and furca area. The shape of the attached calculus was ovoid, trepazoid and polygonal and the calculus was distributed randomly over the root surface. 2. PPD was more than the distance between the gingival margin to the level of attached connective tissue in AP group rather than in HP and MP group. 3. The length of calculus was $2.7mm{\pm}.44mm$ in HP group and $4.1{\pm}.89in$ AP group. 4. The distance between the apical margin of calculus and the level of attached connective tissue was $2.4{\pm}.33mm$ in MP group and $3.4{\pm}.89mm$ in AP group. 5. The length of subgingival calculus was tended to increase in relation to the probing pocket depth. Therefore, it can be concluded, the calculus in periodontal pocket can not be removed completely with supragingival scaling. As the terminal part of calculus was far away with limited distance from the periodontal tissue, it can be said that the calculus was not a direct factor in destroying the periodontal tissue. In this study, the extent of the plaque was not verified but the location of calculus can be used in clinical practice for complete removal of calculus when the distance relation bewteen calculus and plaque will be known.

• Journal of Periodontal and Implant Science
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• v.51 no.6
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• pp.398-408
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• 2021

Purpose: In this study, we aimed to evaluate the clinical validity of the modified tunneling technique using minimal soft tissue harvesting and volume-stable collagen matrix in the anterior mandible. Methods: In total, 27 anterior mandibular teeth and palatal donor sites in 17 patients with ≥1 mm of gingival recession (GR) were analyzed before and after root coverage. For the recipient sites, vertical vestibular incisions were made in the interdental area and a subperiosteal tunnel was created with an elevator. After both sides of the marginal gingiva were tied to one another, a prepared connective tissue graft and volume-stable collagen matrix were inserted through the vestibular vertical incision and were fixed with resorbable suture material. The root coverage results of the recipient site were measured at baseline (T₀), 3 weeks (T₃), 12 weeks (T₁₂), and the latest visit (T_l). For palatal donor sites, a free gingival graft from a pre-decided area avoiding the main trunk of the greater palatine artery was harvested using a prefabricated surgical template at a depth of 2 mm after de-epithelization using a rotating bur. In each patient, the clinical and volumetric changes at the donor sites between T₀ and T₃ were measured. Results: During an average follow-up of 14.5 months, teeth with denuded root lengths of 1-3 mm (n=12), 3-6 mm (n=11), and >6 mm (n=2) achieved root coverage of 97.01%±7.65%, 86.70%±5.66%, and 82.53%±1.39%, respectively. Miller classification I (n=12), II (n=10), and III (n=3) teeth showed mean coverage rates of 97.01%±7.65%, 86.91%±5.90%, and 83.19%±1.62%, respectively. At the donor sites, an average defect depth of 1.41 mm (70.5%) recovered in 3 weeks, and the wounds were epithelized completely in all cases. Conclusions: The modified tunneling technique in this study is a promising treatment modality for overcoming GR in the anterior mandible.