• Proceedings of the Korean Society of Crop Science Conference
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• 2017.06a
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• pp.23-23
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• 2017

Rice (Oryza sativa L.) is the world's most important cereal crop. In crop plant, chlorophyll content and leaf senescence could affect grain filling and yield. We analyzed a QTL associated with chlorophyll content and delayed leaf senescence using high chlorophyll near isogenic line (HC-NIL). HC-NIL derived from a cross between Oryza sativa cv. Hwaseong as a recurrent parent and wild species O. grandiglumis as a donor parent showed higher chlorophyll content than Hwaseong. To identify QTL associated with chlorophyll content, 58 $F_3$ and 38 $F_4$ lines were developed from a cross between HC-NIL and Hwaseong. For QTL analysis, simple sequence repeat (SSR) markers were used for genotyping and one-way ANOVA was conducted. A QTL for chlorophyll content (qCC2) was detected in chromosome 2 and explained 24.63% of phenotypic variation. The senescence effect of the qCC2 was examined in dark-induced incubation (DII). Detached leaves from Hwaseong and HC-NIL were incubated on 3mM MES buffer (pH 5.8) at $27^{\circ}C$ under complete dark condition. After 3 days of incubation, the Hwaseong leaves turned yellow, but the HC-NIL leaves were green. HC-NIL has higher chlorophyll content with delayed senescence than Hwaseong. These results indicated that qCC2 is associated with stay-green phenotype. To know whether the qCC2 is responsible for leaf functionality, ion leakage test and Fv/Fm measurement were performed. Both experiment results showed that differences were observed between Hwaseong and HC-NIL but it was not statistically significant. These results might suggest that the qCC2 is possibly related to chlorophyll content and non-functional stay-green phenotype.

• BMB Reports
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• v.38 no.4
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• pp.432-439
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• 2005

$Ca^{2+}$/calmodulin transduction pathways have been implicated in mediating stress response and tolerance in plants. Here, three genes encoding calmodulin (Cam) members of the EF-hand family of $Ca^{2+}$-binding proteins were identified from Oryza sativa L. databases. Complementary DNA for each of the calmodulin genes, OsCam1, OsCam2, and OsCam3 were sequenced. OsCam1 and OsCam2 encode a conventional 148-amino acid calmodulin protein that contains four characteristic $Ca^{2+}$-binding motifs. OsCam3 encode a similar protein with a 38-amino-acid extension containing a putative prenylation site (CVIL) at the carboxyl terminus. RT-PCR showed that each of the genes is expressed in leaves and roots of 2-week old rice seedlings. By RNA gel blot analysis, OsCam1 mRNA levels strongly increased in response to NaCl, mannitol and wounding treatments. In contrast, OsCam2 mRNA levels were relatively unchanged under all conditions investigated. NaCl treatment and wounding also increased the OsCam3 mRNA level, but in a more transient manner. Our results indicate that although the expression of genes encoding different calmodulin isoforms is ubiquitous, they are differentially regulated by various stress signals. In addition, we have demonstrated that the calcium-channel blocker lanthanum chloride inhibited the induction of OsCam1 gene expression by both NaCl and mannitol treatments. These results suggest that osmotic stress induced expression of OsCam1 gene requires the $[Ca^{2+}]_{cyt}$ elevation that is known to occur in response to these stimuli.

• Korean Journal of Organic Agriculture
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• v.22 no.2
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• pp.321-334
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• 2014

This study was conducted to identify plant growth promoting effects of native plant resources and medicinal plants. 65 kinds of plant extracts from 64 species were evaluated based on two rice(Oryza sativa) seedling bioassays for gibberellins and gibberellin-like substances. 12 extracts of Artemisia princeps stem and leaf, Cirsium japonicum var. maackii whole plant, Rhododendron mucronulatum branch and leaf, Phragmites communis stem, Coix lacryma-jobi var. mayuen whole plant, Lespedeza bicolor branch and leaf, Hydrangea serrata f. acuminata whole plant, Phlomis umbrosa whole plant, Glycyrrhiza uralensis Rhizome, G. uralensis stem and leaf, Angelica gigas root, and Cnidium officinale rhizome showed growth promotion of rice seedlings. Our results suggested that the parts of these plants could be the potential sources as farm-made liquid fertilizers for plant growth promotion.

• The Plant Pathology Journal
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• v.30 no.2
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• pp.208-214
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• 2014

Wild rice, Oryza grandiglumis shows hyper-resistance response to pathogen infection. In order to identify genes necessary for defense response in plants, we have carried out a subtractive hybridization coupled with a cDNA macroarray. An acidic PATHOGENESIS-RELATED1 (PR1) gene of the wild rice is highly identical to the acidic PR1 genes of different plant species. The OgPR1a cDNA has an apparent single open reading frame with a predicted molecular mass 40,621 Da and an isoelectic point of 5.14. Both in silico analysis and a transient expression assay in onion epidermal cells revealed that the OgPR1a protein could be localized in intercellular space in plants. The OgPR1a mRNA was strongly transcribed by the exogenous treatment with ethylene and jasmonic acid as well as protein phosphatase inhibitors. Additionally, ectopic expression of the OgPR1a conferred disease resistance on Arabidopsis to the bacterial and fungal infections.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.42 no.5
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• pp.615-625
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• 1997

An efficient protocol for plant regeneration from protoplasts of the indica rice variety IR43 has been developed. The procedure involved plating of embryogenic suspension-derived protoplasts on the surface of a filter membrane overlaying agarose-embedded feeder cells. Lolium multiflorum cell suspensions were preferable to these of Oryza ridleyi as feeder cells and Lolium suspensions supported colony formation from up to 0.68％ of the protoplasts, depending on the age of cell suspensions. Plant regeneration frequency was significantly improved by using maltose alone or in a 1:1(w/w) combination with sucrose as carbohydrate source and a simple dehydration treatment using a high concentration of agarose in the regeneration medium. Medium containing maltose or maltose mixed with sucrose increased the plant regeneration frequency compared with medium containing sucrose alone. The plant regeneration frequency was increased to 30.7 to 70.7％ following dehydration treatment, while the non-treated controls showed a regeneration frequency of 3.1 to 30.6％. Protoplast-derived plants were transferred to the glasshouse, flowered with morphologically normal.

• Molecules and Cells
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• v.39 no.3
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• pp.250-257
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• 2016

Abiotic stresses such as drought and low temperature critically restrict plant growth, reproduction, and productivity. Higher plants have developed various defense strategies against these unfavorable conditions. CaPUB1 (Capsicum annuum Putative U-box protein 1) is a hot pepper U-box E3 Ub ligase. Transgenic Arabidopsis plants that constitutively expressed CaPUB1 exhibited drought-sensitive phenotypes, suggesting that it functions as a negative regulator of the drought stress response. In this study, CaPUB1 was over-expressed in rice (Oryza sativa L.), and the phenotypic properties of transgenic rice plants were examined in terms of their drought and cold stress tolerance. Ubi:CaPUB1 T3 transgenic rice plants displayed phenotypes hypersensitive to dehydration, suggesting that its role in the negative regulation of drought stress response is conserved in dicot Arabidopsis and monocot rice plants. In contrast, Ubi:CaPUB1 progeny exhibited phenotypes markedly tolerant to prolonged low temperature ($4^{\circ}C$) treatment, compared to those of wild-type plants, as determined by survival rates, electrolyte leakage, and total chlorophyll content. Cold stress-induced marker genes, including DREB1A, DREB1B, DREB1C, and Cytochrome P450, were more up-regulated by cold treatment in Ubi:CaPUB1 plants than in wild-type plants. These results suggest that CaPUB1 serves as both a negative regulator of the drought stress response and a positive regulator of the cold stress response in transgenic rice plants. This raises the possibility that CaPUB1 participates in the cross-talk between drought and low-temperature signaling pathways.

• Korean Journal of Breeding Science
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• v.40 no.3
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• pp.243-249
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• 2008

In the previous study, 141 $BC_3F_2$ lines from a cross between the Oryza sativa cv. Milyang 23 and O. glaberrima were used to identify favorable wild QTL alleles for yield component traits. In this study, we carried out QTL analysis of four grain morphology as well as four yield component traits using 141 $BC_3F_5$ lines from the same cross and compared QTLs detected in two different generations. The mean number of O. glaberrima segments in the 141 $BC_3F_5$ lines ranged from 1 to 13 with 2.69 and 5.71 of the average means of homozygous and heterozygous segments, respectively. There was a three-fold difference in the number of QTLs detected for four traits commonly evaluated in two generations (seven QTLs in the $BC_3F_5$ vs 21 in the $BC_3F_2$ population). The percentages of the phenotypic variance explained by QTLs in the BC3F5 population were similar to or less than those in the $BC_3F_2$ population. This is probably due to the difference in the genetic composition of two populations and the environmental effects. The locations of the QTLs commonly detected in both generations were in good agreement except for one QTL for spikelets per panicle. The yield QTL, yd3 was colocalized with the spikelets per panicle, spp3. Yield increase at this locus is due to the increase in spikelets per panicle, because both traits were associated with increase in spikelets per panicle and yield due to the presence of an O. glaberrima allele. Clusters of QTLs for grain morphology traits were observed in two chromosome regions. One cluster harboring five QTLs near SSR markers RM106 and RM263 was detected on chromosome 2. This population would serve as a foundation for development of the introgression line population from a cross between Milyang 23 and O. glaberrima.

• Korean Journal of Pharmacognosy
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• v.52 no.3
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• pp.170-176
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• 2021

Anthocyanins are considered as one of the major functional components including cyanidin-3-glucoside and peonidin-3-glucoside anthocyanins of black rice (Oryza sativa L., BR) aleurone layer (OAL) extract. The immunomodulatory biological effects of OAL has rarely been evaluated. This study has extensively studied the immunomodulatory effects of BR in immunosuppressed mice by CPA. The immunostimulatory effects of BR extract in in vivo at 150 (OAL-1) and 300 mg/kg body weight (OAL-2) for OAL groups were measured and compared to the normal group (CON) ingested with distilled water only or other groups. After the 14 days of oral administration, immune related organ weights, serum immunoglobulin (Ig) A and IgG, and cytokines (IL-12, TNF-α) levels, splenocytes proliferation rate, and NK cell activity were evaluated as immune related biomarkers. The serum IgA and IgG values in the OAL-treated groups increased to the level of the CON. OAL significantly and effectively controlled the IL-12 and TNF-α levels and NK activity compared to the negative control (NC) group. The results suggest that BR aleurone layer with immunomodulatory activities has a great potential as a functional food by itself or as a supplement.

• Korean Journal of Soil Science and Fertilizer
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• v.37 no.1
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• pp.46-53
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• 2004

In this study, we compared the levels of methylotrophic bacterial community diversity in the leaf, stem, grain, root and rhizosphere soil sainples of four rice cultivars collected from three regions of Korea. Thirty five pigmented and five non-pigmented isolates showing characteristic growth on methanul were obtained. When phylotypes were defined by performing numerical analysis of 42 characteristics, four distinct clusters were formed. While two clusters, I and IV diverged on the basis of nitrate and nitrite reduction, other two clusters, comprising only pink pigmented colonies, diverged on the basis of cellulase activity. Out of the two reference strains used in the analysis, Methyhbacterium extorquens AM1 diverged from all the clusters and M. fujisawaense KACC 10744 grouped under cluster III. All the isolates were positive for urease, oxidase, catalase and pectinase activity and negative for indole production, MR and VP test, $H_2S$ production, starch, and casein hydrolysis. No clusters were found to possess thermotolerant isolates, as no growth of the isolates was observed at $45^{\circ}C$. Two strains in cluster I were found to possess gelatin hydrolysis and methane utilizing properties respectively. Most of the isolates in all the four clusters utilized monosaccliarides, disaccharide and polyols as carbon source. Six isolates showed considerable nitrogenase activity ranging from 86.2 to $809.9nmol\;C_2H_4\;h^{-1}\;mg^{-1}$ protein.

• Korean Journal of Environmental Agriculture
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• v.21 no.2
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• pp.156-161
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• 2002

Two different cDNA clones for superoxide dismutase (SOD) were isolated from an weedy rice variety (Oryza sativa, cv. Bhutan14Ad) and were introduced into a cultivated rice variety (Oryza sativa, cv. Nakdong) in order to develop the environmental stress-resistant rice plants. Sequence analysis of the cloned cDNAS indicated that the deduced amino acid sequence of SOD-A is 88.4% identical to that of SOD-B. Furthermore, the nucleotide sequence of SOD-A is 99.3% identical to that of a Cu/Zn SOD gene of Oryza sativa (GenBank accession No. L36320). The nueleotide sequence of SOD-B was identical to that of the previously published SOD gene (Accession No. D01000). A cultivated rice variety, Nakdong-byeo, was transformed with chimeric SOD genes containing a actin promoter of rice and pin2 terminator using a particle bombardment technique. Transformed calli were selected on an selection medium containing phosphinothricin (PPT). Transgenic rice plants were regenerated from the PPT-resistant calli. PCR analysis with genomic DNAs from transgenic plants revealed that transgenes are introduced into rice genome.