• The Korean Journal of Ecology
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• v.20 no.4
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• pp.233-238
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• 1997

To evaluate allelopathic effect of volatile chemicals and phytohormones, seed germination and seedling growth test of Lactuca sativa have performed in laboratory experiments. Among used chemicals terpienen-4-ol was the most inhibitory to seed germination of lettuce. ABA and GA inhibited seed germination at $5{\times}10^{-6}M$ concentration but promoted germination at $2.5{\times}10^{-5}M$ and $5{\times}10^{-5}M$. ABA and GA alleviated volatile chemical-induced inhibition of seed germination and seedling elongation of lettuce.

• Molecules and Cells
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• v.41 no.4
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• pp.311-319
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• 2018

The gaseous hormone ethylene influences many aspects of plant growth, development, and responses to a variety of stresses. The biosynthesis of ethylene is tightly regulated by various internal and external stimuli, and the primary target of the regulation is the enzyme 1-aminocyclopropane-1-carboxylic acid (ACC) synthase (ACS), which catalyzes the rate-limiting step of ethylene biosynthesis. We have previously demonstrated that the regulation of ethylene biosynthesis is a common feature of most of the phytohormones in etiolated Arabidopsis seedlings via the modulation of the protein stability of ACS. Here, we show that various phytohormones also regulate ethylene biosynthesis from etiolated rice seedlings in a similar manner to those in Arabidopsis. Cytokinin, brassinosteroids, and gibberellic acid increase ethylene biosynthesis without changing the transcript levels of neither OsACS nor ACC oxidases (OsACO), a family of enzymes catalyzing the final step of the ethylene biosynthetic pathway. Likewise, salicylic acid and abscisic acid do not alter the gene expression of OsACS, but both hormones downregulate the transcript levels of a subset of ACO genes, resulting in a decrease in ethylene biosynthesis. In addition, we show that the treatment of the phytohormones results in distinct etiolated seedling phenotypes, some of which resemble ethylene-responsive phenotypes, while others display ethylene-independent morphologies, indicating a complicated hormone crosstalk in rice. Together, our study brings a new insight into crosstalk between ethylene biosynthesis and other phytohormones, and provides evidence that rice ethylene biosynthesis could be regulated by the post-transcriptional regulation of ACS proteins.

• 한국생물공학회:학술대회논문집
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• 2002.04a
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• pp.285-288
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• 2002

This study was conducted to optimize phytohormones combination and concentration on resveratrol production of Vitis vinifera callus cultures. TDZ was so effective for callus proliferation and resveratrol production and can be expected as a stimulus to the cells which keep the ability of producing resveratrol. We optimized the hormone combination of NAA 0.5 mg/L and TDZ 2 mg/L to stimulate resveratrol production very effectively. And callus under MS medium with the optimized phytohormones combination was treated by fungal elicitor, Botrytis.

• Mycobiology
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• v.32 no.3
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• pp.134-138
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• 2004

Water extracts of six plants, such as Allium sativum, A. cepa, Zingiber officinale, Platycodon grandiflorum, Oenanthe javanica, and Capsella brusapastoris, were tested in vitro for inhibitory activity against mycelial growth of anthracnose fungi, Colletotrichum gloeosporioides, C. dematium, and C. coccodes. Among the plant extracts, an Allium sativum extract has good inhibitory effects in all the fungi. Four phytohormones namely, IAA(indole-3-acetic acid), NAA(a-Naphthyl acetic acid), 2,4-D(2,4-Dichloro phenoxy acetic acid) and BAP(Benzyl adenine purine) were used to find out the role over mycelial growth of these fungi. All the concentrations of BAP have good inhibitory effect against mycelial growth of these fungi than that of other tested plant hormones.

• Journal of Life Science
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• v.25 no.4
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• pp.390-396
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• 2015

This study was carried out to investigate the action of phytohormones which influence the adventitious root formation of calli originating from the leaves of Persicaria perfoliata. The optimal medium condition for callus formation was ½-strength MS, 1% sucrose, and 4.5 μM 2,4-D. In order to determine which phytohormones had an effect on the adventitious root formation, the calluses were cultured in various media with different kinds of phytohormones. As a result, the medium with GA₃ or IAA was shown to induce root formation. To deeply investigate the effects of GA₃ and IAA, calli were cultured in 0.1, 1, and 10 mg/l levels of phytohormones. Numbers of roots formed per callus were 10.9, 14.2, 22.6 in GA₃, 5.8, 3.9, 1.1 in IAA, respectively. Therefore, the higher GA₃ or the lower IAA concentration, the more roots formed. To confirm this role of GA₃ we tested with inhibitors PBZ and NPA. GA₃ with PBZ resulted in reduction by 52.4~69.4% compared to GA₃ alone. In contrast, GA₃ with NPA resulted in an increase by -8~45.6% compared to GA₃ alone in root formation. Also, results were determined on the effect of GA₃ with other phytohormones on root formation. Kinetin, 2iP and ABA with GA₃ had a negative effect, but IAA with GA₃ showed a similar result to GA₃ alone. From these results we infer GA plays a key role and auxin has subsidiary activity on adventitious root formation. This is the first report that indicates GA₃ promotes adventitious root formation from calli in P. perfoliata.

• Journal of Ginseng Research
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• v.13 no.2
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• pp.229-233
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• 1989

The effect of some phytohormones and light on the growth, ADC activity and polyamine content in ginseng was studies. In seedlings, the growth, ADC activity and putrescine content were in creased by Ghs treatment. ADC activity ann putrescine content were slightly slightly derreased by ABA, but not changed by kinetin. Light treatment increased ADC activity and putrescine content greatly. In two year ginseng leaves treated by GA3, the ADC actin$.$its reached maximum and the spermidine content reached maximum 2 days faster than in the control. Thtse results suggest the possibility that these regulators are closely related to growth and polyamine cotent. UeVo'ordsEPanaxgineng C.A. Meyer, Polyamine, Putrescine spermidine, arginine decarboxylose, GA3 kiiletin , ABA.

• Journal of Plant Biology
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• v.31 no.2
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• pp.121-130
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• 1988

In order to clarify effects of phytohormones on the viability and the cell wall regeneration of protoplasts isolated from Nicotiana tobacum L. var. BY4, protoplasts isolated from mesophyll tissue were cultured on the Murashige-Skoog liquid media supplemented with auxin(2, 4-D, NAA, IAA) and/or cytokinin (kinetin, BAP, 2ip). Viability of protopplasts was higher in the culture medium containing auxin and cytokinin, especially in the combination of 2, 4-D and BAP. The effectual cell wall regeneration of protolasts was observed when theprotoplasts were cultrued on the medium supplemented with auxin alone, especially with IAA. Cell wall regernation started from 2-3 days after culture and was not detected at budding regions. When the protoplasts were cultured on the phytohormone-free medium, the viability of protoplasts dramatically decreased 4 days after culture.

• Korean Journal of Microbiology
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• v.43 no.4
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• pp.279-284
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• 2007

Two bacterial strains isolated from soil (Bacillus subtilis strains: PS2 and RFO41) were evaluated to determine their promoting effect on the growth of tomato seedling under axonic and pot conditions. The production of phytohormone, such as indole-3-acetic acid, indole-3-butyric acid, gibberellin and zeatin by these two strains was investigated as possible mechanisms for plant growth stimulation. Both PS2 and RFO41 were shown to produce various phytohormones, and. the production of phytohormones was stimulated by the addition of peptone-rich brain heart broth medium. In addition, these bacteria exhibited high levels of phosphatase activity, which ranged from 2.18 to $2.7\;{\mu}\;{\rho}-nitrophenol/ml/hr$. PS2 and RFO41 were applied to the pot test for growth of tomato seed with phosphate. Root and shoot lengths of germinated tomato after 15 days were 45.5% and 36.5% longer than that of control in RFO41 treated samples, respectively. Baciller sp. PS2 and RFO41 may have a potential for biofertilizer in the agriculture.

• Journal of Life Science
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• v.21 no.7
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• pp.969-975
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• 2011

We focused on relationship between phytohormones and AtEXPA3 gene in gravitropic response of A. thaliana. RT-PCR analysis shows that AtEXPA3 was highly expressed in actively developing tissues such as leaf, rosette, root and flower tissues. AtEXPA3 gene expression was enhanced by gravistimulation, BR and IAA. Furthermore, decreased gravitropism was observed when treatment of AVG, an ethylene biosynthetic inhibitor, suggesting that ethylene has a gravistimulating effect itself as well as BRs and IAA. Inhibition of gravitropism in AtEXPA3 RNAi mutant suggests that BR, auxin and ethylene are playing roles as regulators of AtEXPA3. In addition, altered gravitropism in BRs signaling mutant (decreased in bri1-301, bak1, and increased BRI-GFP) indicated that BRs signaling mediated the gravitropism. In conclusion, gravitropic responses of Arabidopsis root resulting from root growth were mediated by increased expression of AtEXPA3 gene, which is stimulated by phytohormones.

• BMB Reports
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• v.43 no.4
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• pp.273-278
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• 2010

The cell cycle is regulated by cyclin-dependent kinase (CDK)-cyclin complexes as well as other regulators. We isolated Kip-related protein 4 (KRP4) cDNA that encodes 289 amino acids including six conserved domains. To investigate the expression pattern of KRP4 as well as of other cell cycle-related genes associated with plant hormones, Arabidopsis seedlings were cultured on MS medium containing auxin or cytokinin. All seedlings treated with phytohormones displayed an increased proportion of cells in S phase. A higher proportion of cells in G2 phase was observed in seedlings treated with NAA. RT-PCR confirmed that the expression of KRP4 was decreased after treatment with phytohormones, and that CDKA and D-type cyclin transcription was increased. Additionally, mitotic cyclins were up-regulated by NAA treatment. These results suggest that KRP4 as well as other cell cycle-related genes might contribute to the control of plant growth in response to exogenous hormones.