• Animal cells and systems
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• v.4 no.3
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• pp.201-214
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• 2000

Two quite different types of plant cells are analysed with regard to transduction of the gravity stimulus: (i) Unicellular rhizoids and protonemata of characean green algae; these are tube-like, tip-growing cells which respond to the direction of gravity. (ii) Columella cells located in the center of the root cap of higher plants; these cells (statocytes) perceive gravity. The two cell types contain heavy particles or organelles (sataoliths) which sediment in the field of gravity, thereby inducing the graviresponse. Both cell types were studied under microgravity conditions ($10^{-4}$/ g) in sounding rockets or spacelabs. From video microscopy of living Chara cells and different experiments with both cell types it was concluded that the position of statoliths depends on the balance of two forces, i.e. the gravitational force and the counteracting force mediated by actin microfilaments. The actomyosin system may be the missing link between the gravity-dependent movement of statoliths and the gravity receptor(s); it may also function as an amplifier.

• Journal of Life Science
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• v.31 no.3
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• pp.280-286
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• 2021

Oryzalin is a herbicide that disrupts the arrangement of microtubules by binding to tubulin, thereby blocking the anisotropic growth of plant cells. Microtubules and microfilaments are cytoskeleton components that have been implicated in plant growth through their influence on the formation of cell walls. Microtubules also play roles in the sedimentation of amyloplasts in the root tip columella cells; this sedimentation is related to gravity sensing and results in downward root growth in the soil for absorption of water and minerals. However, the orientation of microtubules changes depending on the level of ethylene in plant cells. A recent study reported that oryzalin stimulated ethylene production via 1-aminocyclopropane-1-carboxylic acid (ACC) synthase and ACC oxidase and caused a concentration-dependent inhibition of root growth and gravitropic responses. The aim of the present study was to investigate the possibility that oryzalin-induced inhibition might be recovered by the application of inhibitors of ethylene production, such as 10-4 M cobalt ions and 10-8 M aminoethoxyvinylglycine (AVG). The inhibition of root growth and gravitropic response was overcome by 10-20% by an 8 hr treatment with cobalt ions or AVG. These results suggest that ethylene levels could regulate root growth and gravitropic responses in Arabidopsis.

• Journal of Life Science
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• v.25 no.11
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• pp.1223-1229
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• 2015

Oryzalin is a dinitroaniline herbicide, which disrupts the arrangement of microtubules. Microtubules and microfilaments are cytoskeletal components that are thought to play a role in the sedimentation of statoliths and the formation of cell walls. Statoliths regulate the perception of gravity by columella cells in the root tip. To determine the effect of oryzalin on the gravitropic response, ethylene production in primary roots of maize was investigated. Treatment with 10^-4 M oryzalin to the root tip inhibited the growth and gravitropic response of the roots. However, the treatment had no effect on the elongation zone of the roots. An application of 10^-4 M oryzalin for 15 hr to the root tip caused root tip swelling. The application of 1-aminocycopropane-1-carboxylic acid (ACC), a precursor of ethylene, to the root tip also inhibited the gravitropic response. To understand the role of oryzalin in the regulation of the growth and gravitropic response of roots, ethylene production in the primary roots of maize was measured following treatment with oryzalin. Oryzalin stimulated ethylene production via the activation of ACC oxidase (ACO) and ACC synthase (ACS), and it increased the expression of ACO and ACS genes. Indole-3-acetic acid (IAA) played a key role in the asymmetric elongation rates observed during gravitropism. The results suggest that oryzalin alters the gravitropic response of maize roots through modification of the arrangement of microtubules. This might reduce the distribution of IAA in the upper and lower sides of the elongation zone and increase ethylene production, thereby inhibiting growth and gravitropic responses.

• Journal of Life Science
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• v.31 no.2
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• pp.109-114
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• 2021

Oryzalin is a dinitroaniline herbicide that has been known to disrupt microtubules. Microtubules and microfilaments are components of cytoskeletons that are implicated in plant cell growth, which requires the synthesis of cellulose when cell walls elongate. In addition, microtubules are also involved in the sedimentation of statoliths, which regulate the perception of gravity in the columella cells of root tips. In this study, we investigated the effect of oryzalin on the growth and gravitropic response of Arabidopsis roots. The role of ethylene in oryzalin's effect was also examined using these roots. Treatment of oryzalin at a concentration of 10-4 M completely inhibited the roots' growth and gravitropic response. At a concentration of 10-6 M oryzalin, root growth was inhibited by 47% at 8 hr when compared to control. Gravitropic response was inhibited by about 38% compared to control in roots treated with 10-6 M oryzalin for 4 hr. To understand the role of oryzalin in the regulation of root growth and gravitropic response, we measured ethylene production in root segments treated with oryzalin. It was found that the addition of oryzalin stimulated ethylene production through the activation of ACC oxidase and ACC synthase genes, which are key components in the synthesis of ethylene. From these findings, it can be inferred that oryzalin inhibits the growth and gravitropic response of Arabidopsis roots by stimulating ethylene production. The increased ethylene alters the arrangement of the microtubules, which eventually interferes with the growth of the cell wall.

• Archives of Plastic Surgery
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• v.50 no.4
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• pp.335-339
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• 2023

It is undeniable that a significant number of patients who want to improve their facial appearance is increasingly interested in nonsurgical procedures. Without a doubt, the use of autologous fat could not be left out as a magnificent alternative for nasal modeling simply because of four influential factors: ease of collection, compatibility, the temporality of the results, and safety. This work describes an innovative alternative technique for nasal modeling using micrografts enriched with adipose-derived mesenchymal stem cells (ASCs). With this technique, fat was collected and divided into two samples, nanofat and microfat. Nanofat was used to isolate the ASCs; microfat was enriched with ASCs and used for nasal modeling. Lipoinjection was performed in a supraperiosteal plane on the nasal dorsum. Through a retrolabial access, the nasal tip and base of the columella were lipoinjected. We consider that nonsurgical nasal modeling using micrografts enriched with ASCs can be an attractive and innovative alternative. This technique will never be a substitute for surgical rhinoplasty. It can be performed in a minor procedure area with rapid recovery and return to the patient's daily activities the next day. If necessary, the procedure can be repeated.

• Research in Plant Disease
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• v.17 no.1
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• pp.78-81
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• 2011

Soft rot caused by Rhizopus oryzae occurred on unshiu orange (Citrus unshiu Marc.) sampled from commercial markets in Jinju, Korea, 2010. The first symptom of soft rot on orange is a water-soaked appearance of the affected tissue. The infected parts later disintegrated into a mushy mass of disorganized cells followed by rapid softening of the diseased tissue. The lesion on orange was rapidly softened and rotted, then became brown or dark brown. Optimum temperature for mycelial growth of the causal fungus on potato dextrose agar was $30^{\circ}C$ and growth was still apparent at $37^{\circ}C$. Sporangiophores were $6{\sim}20\;{\mu}m$ in diameter. Sporangia were globose and $40{\sim}200\;{\mu}m$ in size. The color of sporangia was brownish-grey to blackish-grey at maturity. Sporangiospores were sub-globose, brownish- black streaked and $4{\sim}10\;{\mu}m$ in size. Columella were globose to sub-globose and $85{\sim}120\;{\mu}m$ in size. On the basis of mycological characteristics, pathogenicity test, and the ITS sequence analysis, the causal fungus was identified as Rhizopus oryzae. To our knowledge, this is the first report of soft rot caused by R. oryzae on unshiu orange in Korea.

• The Korean Journal of Mycology
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• v.40 no.1
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• pp.65-68
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• 2012

In July and August 2011, a disease suspected to be Rhizopus soft rot was observed on peach (Prunus persica var. vulgaris) at the Wholesale Market for Agricultural Products, Jinju, Korea. The first symptom of soft rot on peach is a water-soaked appearance of the affected tissue. The infected parts later disintegrated into a mushy mass of disorganized cells followed by rapid softening of the diseased tissue. The lesion on peach was rapidly softened and rotted, then became brown or dark brown. Optimum temperature for mycelial growth of the causal fungus on PDA was $30^{\circ}C$and growth was still apparent at $37^{\circ}C$Sporangiophores were 6~20 ${\mu}m$ in diameter. Sporangia were globose and 35~200 ${\mu}m$ in size. The color of sporangia was brownish-grey to blackish-grey at maturity. Sporangiospores were sub-globose, brownish- black streaked and 5~10 ${\mu}m$ in size. Columella were globose to sub-globose and 85~120 ${\mu}m$ in size. On the basis of mycological characteristics, pathogenicity test, and molecular identification, the causal fungus was identified as Rhizopus oryzae Went & Prinsen Geerligs. To our knowledge, this is the first report of soft rot caused by R. oryzae on peach in Korea.