• Journal of Plant Biology
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• v.39 no.4
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• pp.279-286
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• 1996

To know the changes of rbcL mRNA level by illumination, Northern hybridization analysis was performed with maize (Zea mays L.cv. Golden X Bantam). The average level of rbcL. mRNA in the light-grown shoots was 3.1 times higher than that of the dark-grown shoots after 6 to 10 growth days. The maximum difference of rbcL mRNA level between the dark-grown and the light-grown shoots was 5.1 folds. These results indicate that accumulation of rbcL mRNAin maize shoots is induced by light. Since the transcriptional DNA binding proteins and their cognate promoter elements, we carried out gel-retardation assays to elucidate the specific binding proteins on the rbcL promoter. It was found that plastid proteins of light-grown shoots bound to the R2 DNA fragment (-33 to -229) and R3 DNA fragment (-230 to -418 from ATG) of the rbcL promoter. From the results of competitive binding assays and heat or protease treatments, it was demonstrated that the bindings were sequence-specific DNA-protein interactions. Therefore, it could be concluded that the rbcL promoter region has at least two specific recognition sites for plastid proteins.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.61 no.3
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• pp.184-190
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• 2016

We investigated the antioxidative and protective effects of corn silk (Zea mays L.) ethanol extracts on human HaCaT cells and erythrocytes. The NICS-2 fraction, extracted from corn silk, exhibited favorable 1,1-diphenyl-2-picrylhydrazyl (DPPH) and 2-azino-bis-(3-ethylbenzothiazoline-6-sulphonic acid (ABTS) radical scavenging activities with $IC_{50}$valuesof$13.3{\pm}0.3{\mu}g/mL$ and $14.2{\pm}0.1{\mu}g/mL$ when compared with those of ${\alpha}$-tocopherol, a positive control, with $IC_{50}=10.4{\pm}02.2$ and $22.2{\pm}3.6{\mu}g/mL$, respectively. In addition, we investigated skin protection effects of NICS extracts of corn silk in HaCaT keratinocytes. To investigate the pharmacological potential of NICS-1 and NICS-2 extracts of corn silk on UV-B-induced damage in HaCaT cells, we measured the activity of interleukin (IL) 1a. Our results showed that all the corn silk extracts inhibited the UV-B-induced activity of IL-1a. In particular, NICS-1 extracts of corn silk significantly suppressed IL-1a activity in a dose-dependent manner without inducing cytotoxicity. These results indicate that the ethanol extracts of corn silk (Zea mays L.) could function as natural cytoprotective agents and antioxidants in biological systems, particularly the skin exposed to UV radiation, by protecting cellular membrane against reactive oxygen species (ROS).

• Journal of The Korean Society of Grassland and Forage Science
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• v.13 no.2
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• pp.122-131
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• 1993

This study was conducted in 1991 and 1992 to determine the effects of winter annual forage corps such as winter rye (Secale cereale L.), rape (Brassica napus subsp. oleifera L.), oats (Auena satiua L.), crimson clover (Trifolium incarnatum L.), vetch (Vicia satiua L.) and Italian ryegrass (Lolim multiflorum Lam.) on subsequent growth, yield and quality of silage corn (Zea mays L.). The winter annual forage crops were seeded at the end of August and harvested in the fall and spring before corn planting. Corn-leaf numbers, plant heights and LA1 were generally reduced during early development when corn followed Italian ryegrass(P<0.05) and winter rye, but the silking date of corn was not affected by the winter annual forage crops. Corn dry matter and TDN yields were significantly reduced when corn followed Italian ryegrass and late maturing Kodiak winter rye. The yield reductions for corn following Italian ryegrass and Kodiak winter rye, relative to corn which did not follow the winter annual forage crops, were 49 and 19% respectively. but the corn yield was slightly improved by 2 and 3%, respectively. when corn followed crimson clover and vetch. No quality differences in corn stover were observed among the treatments except for the lowest ADF and NDF contents and the highest IVDMD where corn followed ltaliabn ryegrass.

• Journal of The Korean Society of Grassland and Forage Science
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• v.20 no.1
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• pp.41-48
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• 2000

This study was conducted to investigate the effects of the application rate of fermented swine manure and additional mineral fertilizer on productivity and nutritive value of corn(Zea mays L.) for silage. Swine manures used in this study were the compost of swine manure fermented with sawdust(SMFWS) and swine sluny(SS). This study was arranged in split-split plot design. Main plots were the types of swine manure, subplots were the application rate of swine manure, such as 100, 200 and 400kgN/ha, and sub-subplots were the application rate of mineral fertilizer, such as 50 and 100kgNiha. Corn DM(dry matter) and TDN(tota1 digestible nutrient) yields increased as application rate of SMFWS and SS increased. DM and TDN yields in SS treatments were higher than those in SMFWS treatments. The effect of fermented swine manure improved positively as application rate of urea increased. Net energy for lactation(NE1) and TDN content in corn decreased as application rate of SMFWS and SS increased, but crude protein(CP) content increased by the application of SMFWS and SS. NE, and TDN contents in SMFWS treatments were lower than those in SS treatments, but CP content in SMFWS was higher than that in SS. The growth and nutritive value of corn were improved by the application of mineral fertilizer. (Key words : Swine manure, Swine sluury, Compost, Zea may, TDN, Net energy)

• KOREAN JOURNAL OF CROP SCIENCE
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• v.41 no.spc1
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• pp.46-68
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• 1996

The objective of this report is to review the up to present papers including 79 references about functional ingredients in maize and their variations. Maize is a good source of such antioxidants as ${\alpha}-,\;{\gamma}-tocopherols,\;{\alpha}-,\;{\beta}-carotene,\;{\beta}-cryptoxanthin$, zeaxanthin, quercetin and chlorogenic acid. Unsaponifiable standard extracts of Zea mays L. (ZML) have a beneficial effect on various dental diseases. Flavonoids, flavonoid biosynthetic pathway and their controling genes were also reviewed in this report. Flavonoids are required for successful fertilization in maize pollen, and maysin has a potent antibiotic activities to earworm and fall armyworm in maize silks. Maize silks have been used in traditional medicine for diuretic, vascular diseases and diabetes, etc. and boiling water extracts of maize silk have hemodynamic effects, but their ingredients still remain obscure.

• Journal of Plant Biology
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• v.37 no.2
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• pp.151-158
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• 1994

Aleurone layers of normal and vp1 mutant maize kernels were extracted and centrifuged at 100,000g to yield a cytosol fraction. Binding of [3H]ABA cis, trans (＋)ABA to a soluble macromolecular components present in the cytosol was demonstrated by Sephadex chromatography and non-denaturing PAGE. The binding component was of high molecular weight and seems to be an aggregate of proteins. A rapid DEAE-cellulose filter method for assaying bound [3H]ABA to a soluble protein was adapted. Binding assays were performed with cytosol that had been preheated or incubated with several enzymes, indicating that heat and protease treatments disrupted the binding. This suggested that binding occurred to proteins. Some properties of the ABA binding proteins were described. The [3H]ABA binding were reduced dramatically when unlabeled ABA was added as a competitor, suggesting a specific binding of [3H]ABA. Gel filtration profiles and autoradiogram of [3H]ABA binding showed no difference in the binding components of Vp1 and vp1/vp1 mutant cytosol, indicating that Vp1 protein is not a sole ABA binding protein.

• Journal of The Korean Society of Grassland and Forage Science
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• v.16 no.1
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• pp.75-80
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• 1996

The corn is one of the most important forage crop in Korea. The harvest time for silage affects dry matter (DM) yield and silage quality. This study was carried out to determine the effect of harvest time on the DM yield and nutritive value of corn forage at the Experimental Livestock Farm, College of Agriculture and Life Sciences, Seoul National University, Suweon in 1991. Forage DM yield and DM content of corn forage significantly increased mainly due to increase of ear. And also the ear to total DM ratio increased from 30% to 55% as the harvest was delayed. Chemical composition of the corn forage was improved by reduction in crude fihr, neutral detergent fiber and acid detergent fiber as the harvest was delayed. This results indicated that the harvest time of corn forage plays an important role to determine DM yield and DM contents for silage materials.

• Journal of Plant Biology
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• v.32 no.3
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• pp.137-144
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• 1989

In order to clarify the effect of the associative nitrogen fixing bacteria on the growth of corn(Zea mays L. Suwon19), we inoculated corn seedlings with Azospirillum amazonense Y1, a micro-aerobic and acid-tolerant nitrogen fixer, and analyzed the growth and dry matter production and changes of nitrogen and phosphorus quantity of the plant during the growing period. The inoculation of associative N-fixing bacgteria increased the growth of height, leaf area, dry weight and total nitrogen quantity of the plant by 15.4%, 65.4%, 33.7% and 38.0%, respectively, on the day of 56th after sowing. Especially the inoculation of A. amazonense Y1 showed two to three-fold accumulation of phosphorus in each organ of plant. The associative bacteria accelerated the growth of the under ground parts more than those of the upper ground parts of corn plant, and caused decrease in T/R ratios.

• Journal of Plant Biology
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• v.34 no.4
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• pp.317-323
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• 1991

Partial recovery in auxin transport capacity from inhibition by N-naphthylphthalamic acid (NPA) was observed when corn coleoptile segments were subjected to a prolonged NPA treatment. Kinetic data indicated that the recovery time is a function of the concentration of NPA applied. Desensitization to NPA was also seen in tissue slices where NPA increased net uptake of auxin, indicating that the apparant adaptation in the auxin transport system did not results possibly from auxin accumulated during transport inhibition. Studies on in vitro binding of NPA to membrane vesicles isolated from the coleoptile indicated that preincubation of the tissue with NPA resulted in the reduced binding activity. Scatchard analysis of the data indicated that this was due to decreases in the number of NPA binding sites. The possibility of causal relationship of modified NPA receptors to the sensory adaptation in auxin transport observed in coleoptile segments will be discussed.

• Journal of Plant Biology
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• v.33 no.4
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• pp.315-320
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• 1990

We investigated the interaction of auxin and Ca2+ on coleoptile segment elongation in seedlings of Zea mays L. Seedlings imbibed and raised either in the presence of 10 mM CaCl2 (HC), or in the absence of Ca2+ (LC) were used. Exposure to 10-5M auxin of coleoptiles from either HC or LC seedlings resulted in strong promotion of elongation. However, longer latent period (90 min) of the auxin effect was observed in HC than in LC seedlings (20 min). The length of latent period observed in HC coleoptiles was proportional to the concentration of CaCl2. The latent period of auxin effect observed in HC seedlings was abolished by pretreatment of the coleoptiles with TMB-8 which inhibits IP3-induced Ca2+ release from the tonoplasts. In segments of LC seedlings, the promotive effect of IAA (10-5M) was abolished by treatment with 5 mM calcium but was reversible upon treatment of the segments with 5 mM EGTA. These results suggest that the effect of auxin on coleoptile elongation is closely related to intracellular Ca2+ level.