• Korean Journal of Environmental Biology
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• v.37 no.4
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• pp.493-502
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• 2019

Maize (Zea mays L.) is a C4-plant and one of the three major crops grown worldwide. Because of its high productivity, maize is considered as one of the most important food and feed stocks in the world. Recently, bioethanol from maize was predominantly generated in the USA and Brazil. Infection of maize by several diseases resulted in a huge disaster and prevented maize production. Downy mildew, caused by Peronosclerospora sorghi, is one of the most serious diseases of maize. Despite efforts to develop downy mildew-resistant cultivars or seed treatment with metalaxyl, downy mildew persists as a serious pathogen and is still prevalent in specific geographical locations. Analysis of soils infected with downy mildew and investigation of candidates associated with downy mildew resistance is an attractive method to overcome downy mildew damage in maize. In a previous study, we reported that maize chromosome 6 carries a possible candidate gene for downy mildew resistance. Using bioinformatics tools and RT-PCR analysis, five novel genes including bZIP, OFP transcription factor, and Ppr were identified as candidate genes associated with downy mildew resistance.

• Journal of Plant Biology
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• v.38 no.1
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• pp.107-113
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• 1995

pRLYS1 containing intact rbcL gene of maize (Zea mays L. cv Golden X Bantam T-51; Zm-A) was digested with several restriction enzymes to construct subcones carrying promoter region of rbcL. The DNA fragments of 0.20, 0.19, 0.92 and 1.55 kb among the EcoRI digests, the EcoRI-DdeI digests, the AvaI digests and the EcoRI-BamHI digests of pRLYS1 were subcloned into pBluscriptSK＋and named pRLPS2, pRLPS3, pRLPS14 and pRLPS35, respectively. Four subclones contain the 1.92 kb portion from 136 nucleotide downstream to 1780 nucleotide upstream from the ATG initiation codon of rbcL gene. pRLPS2 (-29 to -229) and pRLPS3 (-239 to -420 from the ATG) were sequenced. When nucleotide sequence of Zm-A was compared with sequence of rbcL promoter region of a different cultivar of maize (Zea mays L. cv WFG TMS X BS7; Zm-B), the difference rate between two cultivars was 4.3%. The mean of sequence divergence between Zm-A and three grass species in the same tribe, Andropogoneae, in the upstream region from 29 to 420 of ATG was 1.8%, whereas between Zm-B and above-mentioned three species was 5.4%. Therefore, Zm-A seems to evolutionarily closer to three other species in Andropogoneae tribe than Zm-B is.

• Proceedings of the Korean Society of Crop Science Conference
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• 2017.06a
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• pp.111-111
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• 2017

The development and productivity of maize (Zea mays L.) is frequently impacted by water scarcity, and consequently to increased drought tolerance in a priority target in maize breeding programs. To elucidate the molecular mechanisms of resistance to drought stress in maize, RNA-seq of the public database was used for transcriptome profiling of the seedling stage exposed to drought stress of three levels, such as moderate, severe drought stress and re-watering. In silico analysis of differentially expressed genes (DEGs), 176 up-regulated and 166 down-regulated DEGs was detected at moderated stress in tolerance type. These DEGs was increasing degradation of amino acid metabolism in biological pathways. Six modules based on a total of 4,771 DEGs responses to drought stress by the analysis of co-expression network between tolerance and susceptible type was constructed and showed to similar module types. These modules were discriminated yellow, greenyellow, turquoise, royalblue, brown4 and plum1 with 318, 2433, 375, 183, 1405 and 56 DEGs, respectively. This study was selected 30 DEGs to predicted drought stress response gene and was evaluated expression levels using drought stress treated sample and re-watering sample by quantitative Real-Time Polymerase Chain Reaction (qRT-PCR). 23 genes was shown increasing with drought stress and decreasing with re-watering. This study contribute to a better understanding of the molecular mechanisms of maize seedling stage responses to drought stress and could be useful for developing maize cultivar resistant to drought stress.

• Korean Journal of Environmental Agriculture
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• v.19 no.4
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• pp.328-331
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• 2000

Maize (Zea mays L. cv. kosungjaerae and cv. youngwoljaerae) seeds were irradiated with the dose of $0.5{\sim}20$ Gy by $^{60}Co\;{\gamma}-ray$ radiation to investigate the effect of the low dose ${\gamma}-ray$ radiation on the germination rate, early growth and yield. The low dose radiation was able to improve the germination rate and early growth in maize, but the optimal radiation doses were different depended on kinds of cultivars. High stimulatory effect in early growth of maize was observed in 2 Gy irradiation group of kosungjaerae cultivar and in 12 Gy irradiation group of youngwoljaerae cultivar. The optimal radiation dose for the enhancement of yield and yield components in maize was 8 Gy in kosungjaerae cultivar and $4{\sim}12$ Gy in youngwoljaerae cultivar.

• Journal of Microbiology and Biotechnology
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• v.18 no.5
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• pp.805-814
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• 2008

Liming of acidic soils can prevent aluminum toxicity and improve crop production. Some maize lines show aluminum (Al) tolerance, and exudation of organic acids by roots has been considered to represent an important mechanism involved in the tolerance. However, there is no information about the impact of liming on the structures of bacterial and fungal communities in Cerrado soil, nor if there are differences between the microbial communities from the rhizospheres of Al-tolerant and Al-sensitive maize lines. This study evaluated the effects of liming on the structure of bacterial and fungal communities in bulk soil and rhizospheres of Al-sensitive and Al-tolerant maize (Zea mays L.) lines cultivated in Cerrado soil by PCR-DGGE, 30 and 90 days after sowing. Bacterial fingerprints revealed that the bacterial communities from rhizospheres were more affected by aluminum stress in soil than by the maize line (Al-sensitive or Al-tolerant). Differences in bacterial communities were also observed over time (30 and 90 days after sowing), and these occurred mainly in the Actinobacteria. Conversely, fungal communities from the rhizosphere were weakly affected either by liming or by the rhizosphere, as observed from the DGGE profiles. Furthermore, only a few differences were observed in the DGGE profiles of the fungal populations during plant development when compared with bacterial communities. Cloning and sequencing of 16S rRNA gene fragments obtained from dominant DGGE bands detected in the bacterial profiles of the Cerrado bulk soil revealed that Actinomycetales and Rhizobiales were among the dominant ribotypes.

• Journal of Life Science
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• v.25 no.1
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• pp.37-43
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• 2015

We have investigated the effects of the ethylene precursor 1-aminocyclopropane-1-carboxylic acid (ACC), indole-3-acetic acid (IAA) and methyl jasmonate (MeJA) on the development of aerenchyma in the primary root of maize (Zea mays). Because plant hormones affected the longitudinal organization of the primary root, we need an indicator to direct the positions for comparison between control and hormone-treated roots. Therefore, the zones of the maize primary root were categorized as PR25, PR50 and PR75, where each value indicates the relative position between the root tip (PR0) and the base (PR100). Aerenchyma was not observed at PR25 and PR50 and rarely found at PR75 in the cortex of control roots. The aerenchymal area at PR75 increased in the presence of the ethylene precursor ACC or a natural auxin IAA. On the other hand, MeJA differentially acted on non-submerged and submerged roots. Exogenously applied MeJA suppressed the aerenchyma formation in non-submerged roots. When the primary root was submerged, aerenchymal area expanded prominently. The submergence-induced aerenchyma formation was amplified with MeJA. Lateral root primordia have been known to inhibit aerenchymal death of surrounding cells. All the three hormones stimulating aerenchyma formation as described above did not restore the inhibition caused by lateral root primordia, suggesting that the inhibitory step regulated by lateral root primordia can be located after hormonal signaling steps.

• Proceedings of the Zoological Society Korea Conference
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• 2001.10a
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• pp.249.3-250
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• 2001

No Abstract, See Full Text

• Proceedings of the Korean Society of Crop Science Conference
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• 2018.04a
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• pp.44-44
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• 2018

• Proceedings of the Botanical Society of Korea Conference
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• 2001.04a
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• pp.26-26
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• 2001

• Proceedings of the Zoological Society Korea Conference
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• 1997.10b
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• pp.265.2-265
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• 1997

No Abstract, See Full Text