• Journal of Soil and Groundwater Environment
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• v.26 no.1
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• pp.45-53
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• 2021

The removal of 2,4-dichlorophenoxyacetic acid (2,4-D) in aqueous solution by coupled electro-oxidation and Fe(II) activated persulfate oxidation process was investigated. The electrochemical oxidation was performed using carbon sheet electrode and persulfate using Fe(II) ion as an activator. The oxidation efficiency was investigated by varying current density (2 - 10 mA/㎠), electrolyte (Na2SO4) concentration (10 - 100 mM), persulfate concentration (5 - 20 mM), and Fe(II) concentration (10 - 20 mM). The 2,4-D removal efficiency was in the order of Fe(II) activated persulfate-assisted electrochemical oxidation (Fe(II)/PS/ECO, 91%) > persulfate-electrochemical oxidation (PS/ECO, 51%) > electro-oxidation (EO, 36%). The persulfate can be activated by electron transfer in PS/ECO system, however, the addition of Fe(II) as an activator enhanced 2,4-D degradation in the Fe(II)/PS/ECO system. The 2,4-D removal efficiency was not affected by the initial pHs (3 - 9). The presence of anions (Cl- and HCO3-) inhibited the 2,4-D removal in Fe(II)/PS/ECO system due to scavenging of sulfate radical. Scavenger experiment using tert-butyl alcohol (TBA) and methanol (MeOH) confirmed that although both sulfate (SO4•-) and hydroxyl (•OH) radicals existed in Fe(II)/PS/ECO system, hydroxyl radical (SO4•-) was the predominant radical.

• Korean journal of applied entomology
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• v.19 no.2 s.43
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• pp.91-95
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• 1980

The experiment was conducted to culture callus tissue induced from foliage leaf of garlic bulb for the production of virus-free stocks and for the reduction of expenses for seeds, The following results were reached. 1. Linsmaier-Skoog basal medium containing 2,4-dichlorophenoxyacetic acid (2,4-D) $10^{-5}M$ and benzyladenine $10^{-5}M$ showed the most effective for the induction for the induction of garlic callus. 2. The growth rate of callus was the highest in Linsmaier-Skoog basal medium containing kinetin $10^{-6}M\;and\;2,4-D\;10^{-6}M$ 3. The results of periodical assay of virus concentration in callus tissues showed that virus was almost eliminated by repeated transfer of translucent and soft tissue for eight generations. 4. When virus-free garlic callus tissues were transfered to Murashige-Skoog basal medium containing kinetin $10^{-5}M$ and naphthaleneacetic acid $5\times10^{-6}M$, the tissues were redifferentiated and formed plantlet.

• Korean Journal of Agricultural Science
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• v.9 no.2
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• pp.461-466
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• 1982

Lower and upper petiole segments of strawberry plants (Fragaria${\times}$ananassa) were cultured on Murashige and Skoog (MS) medium containing 2mg/liter Benzylamino purine (BA), 0.02mg/liter 2,4-dichlorophenoxyacetic acid (2,4-D), or their coinbination. Of the lower petiole segments, 55% or more were differentiated on the media containing $2mg/{\ell}\;BA$ or $2mg/{\ell}\;BA+0.02mg/{\ell}\;2,4-D$. There was no significant difference in results be tween these treatments. BA did not influence root formation. No shoots we re initiated from the upper petiole segments. Root formation was stimulated by the $0.02mg/{\ell}\;2,4-D$ medium, whereas it inhibited shoot formation. Upper petiole segments produced more roots than did lower petiole segments.

• Journal of Plant Biotechnology
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• v.34 no.3
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• pp.197-200
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• 2007

Mature seeds of Artemisia annua L. were placed onto Murashige and Skoog's (MS) medium supplemented with $4.52\;{\mu}M$ 2,4-dichlorophenoxyacetic acid (2,4-D). After 6 weeks of culture, off-white, compact calluses were formed on the plumule of seedlings at a frequency of 5.9%. Calluses were subcultured on the same medium. After an additional 2 weeks of subculture, calluses produced a few somatic embryos at a frequency of 28.8%. Upon transfer to MS basal medium, calluses producing a few somatic embryos gave rise to numerous somatic embryos, which subsequently developed into plantlets. Plantlets were successfully transplanted to potting soil and grown to maturity in a greenhouse.

• Journal of Environmental Science International
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• v.20 no.2
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• pp.185-197
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• 2011

Sorption of chlorinated pesticides such as 2,4-dichlorophenoxyacetic acid (2,4-D) and atrazine onto natural clays (montmorillonite and zeolite) modified with cationic surfactant, hexadecyltrimethyl-ammonium (HDTMA) and a natural soil was investigated using batch adsorbers. The clays were transformed from hydrophilic to hydrophobic by the cation exchange between clay surface and HDTMA up to 100% of the cation exchange capacity (CEC). Physicochemical characteristics of the sorbents such as pH, PZC (point of zero charge), organic carbon content ($f_{oc}$), fourier transform infrared spectroscopy (FT-IR), differential thermogravimetric analysis (DTGA) and X-ray diffraction (XRD) were analyzed. Sorption isotherm models such as Freundlich and Langmuir were fitted to the experimental data, resulting Langmuir model ($R^2$ > 0.986) was fitted better than Freundlich model ($R^2$ > 0.973). Sorption capacity ($Q^0$) for 2,4-D and atrazine was in the order of HDTMA-montmorillonite > HDTMA-zeolite > natural soil corresponding to the increase in organic carbon content ($f_{oc}$). The sorption of the pesticides was also affected by pH. The sorption of 2,4-D decreased with the increase in pH, whereas that of atrazine was not changed. This indicated that the sorption capacity ($Q^0$) of 2,4-D and atrazine was not affected by the solution pH because they exist as anionic (deprotonated) forms at pH above pKa. The results indicate that organoclay has a promising potential to reduce chlorinated pesticides in the effluent from golf courses.

• Journal of Plant Biology
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• v.35 no.4
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• pp.409-414
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• 1992

Effect of quercetin, a kind of natural plant flavonoids, on auxin-induced ethylene production in barley coleoptiles was studied. Auxin-induced ethylene production was apparently stimulated by quercetin. This stimulatory effect of quercetin appeared after 4 h of incubation period. Ethylene production was stimulated 200% over the control after 8 h of incubation by $3{\times}10^{-5}\;M$ quercetin. The quercetin effect was most prominent at $10^{-4}\;M$ of IAA. Ethylene production induced by the synthetic auxin, 2,4-D and NAA, was not significantly affected by quercetin. Also ACC-based ethylene production was unaffected by the flavonoid. In an effort to elucidate mechanisms of quercetin action on auxin-induced ethylene production, the effect of quercetin on 1M metabolism was studied. Data obtained from these experiments indicate that quercetin treatment resulted in about 90% inhibition of IAA oxidase activity. IAA ($3{\times}10^{-5}\;M$) conjugation was found to be not affected by quercetin. This results suggest that the stimulatory effect of quercetin on auxin-induced ethylene production may be due to the fact that quercetin inhibits 1M oxidase activity, thus increasing the free IAA level.

• Journal of Plant Biology
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• v.32 no.3
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• pp.145-150
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• 1989

Mature zygotic embryos dissected from ginseng(Panax ginseng C. A. Meyer) seeds were cultured on Murashige and Skoog's (MS) medium containing various concentrations of 2, 4-dichlorophenoxyacetic acid(2, 4-D) and kinetin. Somatic embryos were induced directly from cotyledonary tissue or from intervening callus. The induction frequency of somatic embryos was up to 55%. Upon transfer to half-strength MS medium supplemented with 1 mg/1 6-benzyladenine(BA) and 1 mg/1 GA3, most somatic embryos developed into plantlets. Over 50% of the plantlets flowered after 4 weeks of culture and then a few bore immature fruits in vitro. Therefore, it is suggested that the juvenility of the ginseng tissue which give rise to somatic embryos does not interfere with in vitro flowering of their regenerated plantlets.

• Journal of Plant Biology
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• v.33 no.4
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• pp.271-276
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• 1990

Our study was carried out for plant regeneration via somatic embryogenesis from immature seeds of Bletilla striata. The highest frequency of embryogenic callus formation was obtained from the immature seeds (at 150 days after pollination) cultured on Hyponex and VW medium supplemented with 3 mg/l 2,4-dichlorophenoxyacetic acid (2,4-D) and 1 mg/l kinetin under the dark condition. Multiple somatic embryos were induced when embryogenic callus was transferred to VW medium without growth regulators under continued illumination. Somatic embryos were observed histologically with scanning electron microscopy. Regeneration of Bletilla striata was obtained from somatic embryos with a well-defined scutellum and coleoptile as well as with one or more shoot primordia and root primordia. We think that these methods for orchid multiplication must be useful to access clonal propagation of orchids.

• Journal of Plant Biotechnology
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• v.37 no.2
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• pp.228-235
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• 2010

The establishment of cell suspension culture and plant regeneration of the halophytic Leymus chinensis (Trin.) are described in this study for the first time. Callus induction solid medium containing Murashige and Shoog (MS) basic salt, $2.0\;mg\;l^{-1}$ 2,4-dichlorophenoxyacetic acid (2,4-D), and $5.0\;mg\;l^{-1}$ L-glutamic acid with $30.0\;g\;l^{-1}$ sucrose and $4.0\;g\;l^{-1}$ gelrite for solidification induced the highest rate of cell division in Type 1 callus among calli of various types. Liquid medium with the same hormone distribution was therefore, used for cell suspension culture from Type 1 callus. Over a 30 d suspension culture at 100 rpm, great amounts of biomass were accumulated, with 71.07% average daily increment and 22.32-fold total fresh weight increment. Comparison of before and after suspension culture, the distribution of different size callus pieces and the maintenance of callus type were basically unaltered, but a slight increase in relative water contents was observed. To induce the potential of plant regeneration, the directly transferring on plant regeneration solid medium containing MS basic salt, $0.2\;mg\;l^{-1}$ $\alpha$-naphthalene acetic acid (NAA), $2.0\;mg\;l^{-1}$ kinetin (Kn), and $2.0\;g\;l^{-1}$ casamino acid and indirectly transferring were simultaneously performed. Even now growth rates of suspension-derived callus on solid medium were approximately half of those of Type 1 callus, but faster somatic embryogenesis was observed. Rooting of all regenerated shoots was successfully performed on half-strength MS medium. All plants appeared phenotypically normal.

• Proceedings of the Plant Resources Society of Korea Conference
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• 2018.10a
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• pp.89-89
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• 2018

우리나라, 중국 및 일본을 포함한 동북아시아가 원산이며 바이오매스량이 많은 억새(Miscanthus spp.)는 바이오에너지 생산을 위한 원료작물로서 가치가 높아, 바이오에탄올 생산용 원료작물로 주목을 받고 있다. 독일 등 유럽과 미국에서는 바이오에탄올 생산용 작물로 주로 종간 교잡 이질 3배체인 불임성 억새(M. x giganteous)를 대상으로 연구하고 있다. 이렇게 단일유전형을 갖는 품종의 재배에는 특정 병과 해충에 약하며 자연재해에도 취약성을 나타내므로 억새가 바이오에너지작물로 자리 잡기 위해서는 다양한 유전형의 억새 품종 개발이 필요하다. 본 연구는 우리나라의 자생 억새 3종을 기내배양하고 탈분화 및 재분화 시스템을 구축하여 억새 품종 육성 시 효율을 높이기 위해서 실시하였다. 억새 종자로부터 캘러스의 유도는 MS배지보다 N6배지 에서 좋았으며, 식물생장조절제로 2,4-Dichlorophenoxyacetic acid (2,4-D)와 6-Benzyl aminopurine (BA)를 조합처리한 처리구보다 2,4-D만을 단독처리하였을 때 캘러스 유도율이 더 높았다. 억새 종에 따른 캘러스 유도율은 물억새가 가장 낮고, 거대억새가 가장 높았으며, 3 ~ 5 mg/L의 2,4-D가 첨가된 N6배지에서 배발생 캘러스(embryogenic callus)가 발생하였다. 억새 신초 및 줄기의 절간에서의 캘러스 유도율은 전반적으로 종자에 비하여 낮았으며, 미성숙화기로부터의 캘러스 유도는 억새 종에 따른 차이가 없었으며, 5mg/L의 2,4-D가 첨가된 배지에서 캘러스 유도율이 가장 높게(90 ~ 95%) 나타났다. 형성된 배발생 캘러스로부터 식물체의 재분화는 N6배지에서는 재분화 식물체가 발생하지 않았고, 1 ~ 3mg/L의 BA와 0.1ml/L의 1-Naphthaleneacetic acid (NAA)가 첨가된 MS배지에서만 식물체가 재분화되였다.