The influence of rainfall during the ripening stage on pre-harvest sprouting, seed viability, and seed quality was investigated in two Korean rice cultivars, Shindongjin and Hopum. When the rainfall was artificially treated in a greenhouse, HP started to pre-harvest sprouting at three days of rainfall treatment (DRT), but Shindongjin did not show pre-harvest sprouting at 40 DAH treatment and just 0.3~0.8% at 50 DAH, which was much lower than 15.3~ 25.8% of Hopum in the same treatment. After harvest, the seed germination of Hopum decreased about 10~25% compared to non-treated seeds, but that of Shindongjin decreased much little rate than that of Hopum. The seed longevity tested by accelerated aging decreased with prolonged rainfall period in both cultivars, but the varietal difference was clear; Shindongjin could withstand longer accelerated aging than Hopum. Shindongjin maintained its germination (>50%) ability after 15 days of accelerated aging regardless of the rainfall treatment period and time, but Hopum dropped below 50% germination ability after only 5 days of accelerated aging. In conclusion, rainfall during the ripening stage induced not only pre-harvest sprouting, but also reduced seed quality and longevity during storage, which varied between two cultivars.

The White backed planthopper (WBPH), Sogatella furcifera (Horvath) is one of the serious insect pests in rice growing region in Asia. When rice is attacked by the insect it releases secondary metabolites for self-defense. In this study, we identified WBPH-mediated compounds from a cross ‘Cheongcheongbyeo/Nagdongbyeo’ doubled haploid (CNDH). The compounds were located in chromosome. Leaves and stem of CNDH lines were infected by 2∼3 insta of 3 weeks WBPH and samples were extracted by 90% methanol. Extracted compounds were analyzed through HPLC. TLC was used in separating the target compounds. QTL analysis of compound was done using winQTLcart 2.5 program. Chrysoeriol was highly contained in Cheongcheongbyeo. QTL location is found on chromosome by winQTLcart 2.5. QTL analcited with compound7 was detected on chromosome 4, 7 and 12. qFla4 was detected on chromosome 4 in RM280-RM6909 at LOD 3.5 with 30% of variation. qFla7 was detected on chromosome 7 in RM248-RM1134 with LOD 3.0 with 30% of variation. qFla12 was detected on chromosome 12 in RM1226-RM12 with LOD 2.7 with 40% of variation. Cochlioquinone was detected on chromosome8, qFla8 in RM23230-RM3689 with LOD 2.5 with 30% of variation. Chrysoeriol and Cochlioquinone separated to condition of (Chloroform: Methanol:1-Butanol:Water=4:5:6:4). Separated compounds were analyzed by LC/MS and NMR. These results, investigation is being done to ditermine how the secondary metabolites come lead to pathways of genes and its effect on WBPH relation.

The seed shattering played a key role in the crucial step of rice domestication. Because it has been important to increase the yield human had to select the rice varieties and species with low shattering degree. The shattering habit of rice is considered to be under the relatively simple genetic control compared with other characteristics related to domestication. Several recessive genes associated with the formation of an abscission layer, sh2, sh4 and sh-h on chromosomes 1, 3 and 7, have been reported. In addition, the grain shattering of rice is considered to be caused by seed abscission. The morphology of the abscission layer can differ in many different rice varieties that show varying degrees of shattering. Accordingly, it is important to elucidate the molecular mechanism to determine why some varieties do not have abscission layers and have an easy-shattering trait. In this study, analysis of QTL for grain shattering was performed to determine the location of QTLs on the whole chromosomes of rice. Also, we tried to construct a physical map for qPs6

Rice embryo contains valuable materials which are related to human health and industrial material, thus controlling embryo size is more and more important in the field of rice breeding. Especially, main health-aid components such as γ -aminobutyric acid (GABA), tocopherol and vitamins showed positive-correlation with embryo size. We obtained three enlarged embryo character mutants derived from Hwacheongbyeo (Korean japonica cultivar) by treatment of chemical mutagen, N-methyl-N-nitrosourea(MNU). These three mutants were named according to their embryo size as ge-m, ge, ge-s. The result of allelism test between Hwacheongbyeo, ge-m, ge and ge-s represented that the embryo size of ge and ge-s was controlled by the same gene(Giant embryo, GE). Through GE locus sequencing of three mutants, we found that each of ge and ge-s mutant has a point mutation, causing non synonymous amino acid substitution. On the other hand, ge-m mutant, the embryo of which featured intermediate size in between those of Hwacheongbyeo and ge, turned out to be non-allelic to the GE locus, suggesting it is likely a novel gene, which influences rice embryo development through a different mechanism than GE gene. Fine mapping of ge-m is currently in progress. This work was supported by a grant from the Next-Generation BioGreen 21 Program (Plant Molecular Breeding Center No. PJ008125), Rural Development Administration, Republic of Korea.

It is assumed that air temperature and light intensity may influence thermal image of plants but little effort has been made to these environmental factors. We conducted this study to investigate the effects of these environmental factors on the thermal image of rice and thus to optimize the condition for thermal image acquisition for high-throughput screening of salt-tolerant rice. Rice (Oryza sativa cv. Chucheong-byeo) seedlings at the four-leaf stage were treated with 0, 50, and 100 mM of NaCl for salt stress. Thermal images (T420, FLIR, Sweden) were taken at 1 and 2 days after salt treatment under 4 different air temperatures and 3 light intensities. Thermal images were analyzed using FLIR Tools 3.1 (FLIR systems Inc., USA) and MATLAB 8.1 (The MathWorks Inc., USA). Rice leaf temperature increased significantly with increasing air temperature and light intensity, resulting in greater discrimination between salt-stressed and unstressed rice plants. Our results thus conclude that environmental conditions such as air temperature and light intensity affect rice thermal image and their optimization is essential for better image acquisition and high-throughput screening system based on thermal image analysis

Since global climate changes drastically, pre-harvest sprouting (PHS) is expected to pose serious problems in rice production. CBL-interacting serine/threonine protein kinases (CIPKs) have been implicated to play important role in regulating various abiotic stresses such as cold, salinity and drought. In this study, to understand the function of this gene under pre-harvest sprouting in rice, a cDNA clone encoding CBL-interacting protein kinase 15 (CIPK15) was isolated from rice flowers. This gene is 2,818 bp long with 1,332 bp coding region that encodes a polypeptide of 443 amino acids. We constructed a recombinant vector carrying the OsCIPK15 under the control of the CaMV 35S promoter and Tnos terminator and transformed into rice using Agrobacterium tumefaciens. Insertion of the gene was verified in transformants using HPT resistance test and genomic PCR. Transcriptional profiling using tissues of wild type, Gopum, revealed expression of the gene in whole plant tissues with level of expression highest in the seeds suggesting possible role in dormancy. Comparative expression analysis of the gene in transgenic and wild type through semi-quantitative RT-PCR and real-time PCR showed higher expression in transgenic rice lines. Moreover, screening in the mist chamber showed overexpression lines that were resistant to the PHS. This result suggests the involvement of OsCIPK15 in the regulation of pre-harvest sprouting.

Rice blast (Magnaporthe oryza B.) is one of the most widespread and devastating diseases of rice. Screening of valuable genetic resources harboring resistance genes is one of the most efficient approaches against blast disease. Because the bioassay to rice blast in the field shows high variations, this study has performed to provide DNA profiles in the accessions of diverse countries using major blast resistant genes linked markers, identified and mapped in different genotypes of rice. Because durable resistance to blast is controlled by a combination of major resistance genes, we surveyed the distribution of blast resistant genes in the 1,500 accessions using major 12 blast resistance genes linked markers. These resistant genes found that the frequency distribution of Pi-39 (66.9%), Pik-m (41.9%), Pit (40.5%), Pii (21%), Pib (19.3%), Pi-d(t)2 (12.7%), but Pita, Pita/Pita-2, Pik, Piz-t, Pi5 genes were identified in less than 10% frequency. Most of accessions contain from 1 to 4 different resistant genes. Pi39 and Pik-m genes amplified in the 69.1% and 51.7% among 356 Korean accessions, Pi39 (79.6%) and Pib (55.8%) in 113 China, Pit (80.6%) and Pib (32%) in 103 Philippines, respectively. In this study, we evaluated the blast resistance degree and the information about the distribution of rice blast resistant genes in rice germplasm. This study will help to develop effective strategies for managing rice blast disease in rice germplasm.

국내 식물자원 및 약용식물들의 식물 생장촉진 효과를 조사하기 위하여 64종 65점의 추출물 시료를 조제하여 벼(Oryza sativa) 유묘 생장에 미치는 영향을 평가하였다. 그 결과, 11종 12점의 쑥(Artemisia princeps) 경엽, 엉겅퀴(Cirsium japonicum var. maackii) 전초, 진달래(Rhododendron mucronulatum) 가지와 잎, 갈대(Phragmites communis) 줄기, 율무(Coix lacrymajobi var. mayuen) 전초, 싸리(Lespedeza bicolor) 가지와 잎, 산수국(Hydrangea serrata f. acuminata) 전초, 속단(Phlomis umbrosa) 전초, 감초(Glycyrrhiza uralensis) 근경, 감초(G. uralensis) 경엽, 당귀(Angelica gigas) 뿌리 및 천궁(Cnidium officinale) 근경 추출물은 벼 유묘 생장을 촉진시키는 것으로 나타났다. 본 결과에 따라 상기 식물 종의 부위들은 식물 생장 촉진용 농가 자가제조 액비 개발을 위한 소재로써 활용가능성이 있는 것으로 판명되었다.

1. 토양조건은 배수가 양호한 양토인 안룡통 보통답으로 칼륨을 제외하고는 우리나라 논토양의 평균 함량보다 낮은 토양이었다. 유기질비료로 처리구는 질소 표준시비량인 9kg/10a과 비슷한 N-P-K=8.45-4.89-9.24kg/10a를 시용한 반면 관행구는 표준시비량보다 많은 N-P-K=14.5-6.3-10.8kg/10a를 시용하였다. 2. 벼 수확 후 시험구 토양내 미생물상 분포를 조사한 결과 박테리아와 방선균의 수는 처리구에서 약간 높게 나타났고, 곰팡이의 수는 관행구에서 약간 높게 나타났다. 토양내 가수분해효소 생성미생물을 조사한 결과 호평벼 처리구에서 키틴분해미생물과 인산분해미생물 분포가 다소 높게 나타났다. 3. 병해충 발생정도는 전체적으로 처리구에서는 미미하게 발생하였다. 그러나 관행구에서 특히 호평벼에서 도복과 이삭도열병이, 잎집무늬마름병은 두 품종 공히 심하게 발생하였다. 혹명나방은 온누리에서 발생율이 높았는데 이는 질소 과다 시용으로 판단되었다. 4. 호평벼와 온누리 공히 관행구가 처리구에 비해 간장과 수장은 약간 길고, 주당수수는 많았다. 그러나 잎집무늬마름병 및 이삭도열병, 혹명나방 도복 등으로 등숙비율이 현저히 떨어졌다. 관행구는 천립중이 낮았으며 수량이 호평벼는 38%, 온누리는 13% 떨어졌다. 5. 병해충인 이삭도열병, 잎집무늬마름병, 혹명나방과 수량과의 관계에서 유의성이 높은 부의 상관관계가 나타났다. 6. 백미의 품질도 관행구에서 쇄립율의 증가로 완전미 비율은 낮고, 단백질함량이 높아 전반적인 품질 및 윤기치가 낮아졌다.

A field study was conducted to understand nitrogen use efficiency of high yielding Japonica rice varieties under three levels of nitrogen fertilizer (90, 150 and 210 kg N ha -1 ) in Iksan, Korea. Two high yielding rice varieties, Boramchan and Deuraechan, and an control variety, Dongjin2, were grown in fine silty paddy. Nitrogen use efficiencies (NUE) were 83.3, 56.3, and 41.2 in 90, 150, and 210 kg N ha -1 fertilizer level, respectively. Total nitrogen uptake varied significantly among nitrogen levels and varieties. Variety Dongjin2 showed the highest nitrogen uptake efficiency (NUpE), while Boramchan and Deuraechan showed higher nitrogen utilization efficiency (NUtE). However, Nitrogen harvest index (NHI) was higher in Boramchan (0.58) than Deuraechan (0.57) and Dongjin2 (0.53). Rough rice yield showed linear relationship with total nitrogen uptake (R 2 =0.72) within the range of nitrogen treatments. Boramchan produced significantly higher rough rice yield (8546 kg ha -1 ) which mainly due to higher number of panicles per m 2 compared to Deuraechan (7714 kg ha -1 ). Deuraechan showed higher number of spikelets per panicle, but showed lower yield due to lower number of panicle per m 2 . Rice varieties showed different nitrogen uptake ability and NUE at different nitrogen level. Plant breeders and agronomist should take advantage of the significant variations and relationships among grain yield, NUpE, and NUE.

The required for Mla12 resistance (RAR1) protein is essential for the plant immune response. In rice, a model monocot species, the function of Oryza sativa RAR1 (OsRAR1) has been little explored. In our current study, we characterized the response of a rice osrar1 T-DNA insertion mutant to infection by Magnaporthe oryzae, the causal agent of rice blast disease. osrar1 mutants displayed reduced resistance compared with wild type rice when inoculated with the normally virulent M. oryzae isolate PO6-6, indicating that OsRAR1 is required for an immune response to this pathogen. We also investigated the function of OsRAR1 in the resistance mechanism mediated by the immune receptor genes Pib and Pi5 that encode nucleotide binding-leucine rich repeat (NB-LRR) proteins. We inoculated progeny from Pib/osrar1 and Pi5/osrar1 heterozygous plants with the avirulent M. oryzae isolates, race 007 and PO6-6, respectively. We found that only Pib-mediated resistance was compromised by the osrar1 mutation and that the introduction of the OsRAR1 cDNA into Pib/osrar1 rescued Pib-mediated resistance. These results indicate that OsRAR1 is required for Pib-mediated resistance but not Pi5-mediated resistance to M. oryzae.

This study investigated the nutrients and anti-nutrients of produced resveratrol GM rice (Iksan-515, Iksan-526, Dongjin) that were cultivated Iksan and Suwon regions. Among the rice samples, Iksan-515 and Iksan-526 are produced resveratrol GM rice. Reveratrol is health-beneficial compound with strong antioxidant and antitumor activities. Red wine is believed to the main source of resveratrol in the human diet. Recent studies have associated resveratrol with the cardio-protective effect observed among people with moderate resveratrol consumption. Moreover, resveratrol has been possess chemoprotective activity. In present study, we determined the substantial equivalence between GM rice and seedling sort. We investigated the nutrients and anti-nutrients of produced resveratrol GM rice and analyzed nutrients including moisture, crude fat, ash, crude protein, fatty acids, amino acids and minerals. The results of this analysis showed equivalence between GM rice and non-GM rice. We determined phenolic compounds including naringenin, vallin and investigated 4 tocopherols (α-, β-, γ-, δ-tocopherol) and 4 tocotrienols (α-, β-, γ-, δ-tocotrienol). Among the all rice cultivars, they showed substancial equivalence between resveratrol GM rices and non-GM rice.

We used a microarray dataset that is deposited in the public database to evaluate plant responses to heat stress and selected two genes, OsSHSP1 (Os03g16030) and OsSHSP2 (Os01g04380), that are highly expressed under heat stress in rice. OsSHSP1 and OsSHSP2 gene transcripts were highly induced in response to salt and drought. In addition, OsSHSP1 and OsSHSP2 gene transcripts were induced under ABA and SA. Subcellular localization of proteins of 35S::OsSHSP1 were associated with the cytosol, whereas those of and 35S::OsSHSP2 were associated with the cytosol and nucleus. Heterogeneous overexpression of both genes exhibited higher germination rates than those of wild-type plants under the salt treatment, but not under heat or drought stress. The network of both genes harboring 9 sHSPs as well as at least 13 other chaperone genes might support the idea of a role for sHSPs in the chaperone network. Our findings might provide clues to shed light on the molecular functions of OsSHSP1 and OsSHSP2 in response to abiotic stresses, especially heat stress.

Amylopectin composition is determined by the relative activity of soluble starch synthase (SSS) and granule-bound starch synthase (GBSS). Soluble starch synthase and starch branching enzymes are major determinants for the synthesis of amylopectin while GBSS1 is responsible for amylose synthesis in vivo. The formers are made of linear and branched molecules and the latter is composed of highly branched molecules. To increase the palatability of rice, down-regulation of amylose synthesis by antisense and RNA interference (RNAi) could be excellent and powerful tools for controlling the starch composition which is responsible for grain eating quality. The goal of this study is to generate breeding lines with lower amylose content relative to its wild type. This study also reports the results of the two down-regulating technology in lowering the amylose content of rice grain. Furthermore, this study elucidates the effect of using antisense and RNAi for SSS1 and GBSS1.

Plant transformation systems have been developed using several different approaches, and the development of reliable and efficient transformation systems is still one of the most important breakthroughs in molecular biology and biotechnology of rice. However, there are many cultivars in rice and transformation efficiency is dependent on the cultivar. The conventional Agrobacterium-mediated rice transformation system using secondary calli requires 14-16 weeks for establishing transgenic plantlets, and it is thought that somaclonal variation through the Tos17 retrotransposon occurs during the tissue culture stage. Here, we modified an Agrobacterium-mediated transformation system in rice cultivar Dongjin, adding an endosperm removal step that is critical to transformation frequency and changing the Agrobacterium strain and media composition. This method increased transformation efficiency and stability. These results will provide valuable information for scientists to use a reliable and efficient rice transformation system.

The HWC-line of rice showed wide compatibility with both indica and japonica cultivars, tall culm length, long and slender grain shape. For QTL analysis, two F2 populations were derived from the crosses between the HWC-line and each of two Korean variety, Dasanbyeo (Korean Tongil-type cultivar) and Hwacheongbyeo (temperate japonica cultivar), respectively. A total of 190 F2 plants were evaluated in each of two F2 populations. Eight agronomic characters were measured for QTL analysis in F2 populations and parents. Two molecular linkage maps were constructed. In the F2 population from cross between HWC-line / Dasanbyeo (HD) cross, 93 STS markers and 13 SSR markers were mapped on 12 chromosomes, covering a total length of 1942.6 cM, with an average distance of 18.33cM between adjacent markers. In the F2 population from HWC-line / Hwacheongbyeo (HH) cross, 28 STS markers, 29 SSR markers and 1 FNP marker were mapped on 11 chromosomes, spanning a total length of 925.53cM, with an average distance of 15.96cM between adjacent markers. In the F2 population from HD cross, 16 M-QTLs and 1 E-QTL were detected for culm length, spikelets per panicle, spikelet fertility, grain length, grain width, grain shape and 100 grains weight. 7 QTLs of spikelet fertility, grain length, grain width and grain shape were newly identified in this study. In the F2 population from HH cross, 15 M-QTLs were detected for culm length, panicle length, spikelet fertility, grain length, grain width, grain shape and 100 grains weight. 6 QTLs of culm length, grain length, grain width and grain shape were newly identified in this study. The QTLs identified in this study would provide basic information on putative functional genes related agronomic characters and facilitate breed new rice cultivar.

Ionizing radiation is known to cause chromosomal alterations such as inversions and deletions and affects gene expression within the plant genome. To monitor the genome-wide transcriptome changes by ionizing radiation, we used rice Affimetrix GeneChip microarray to identify genes that are up- or down regulated by gamma-ray (200 Gy, 60Co source), cosmic-ray and ion beam (40 Gy, 220 MeV carbon ion). The overall expression patterns between gamma-ray and ion beam were similar but cosmic-ray was regulated differently. Combined results from all 3 radiations identified 27 up-regulated genes and 188 down regulated genes. These results mean the induction of similar mechanism changes in treatments of gamma ray and ion beam. However the different expression in treatment of cosmic-ray might be due to the other environmental conditions. Among the commonly up- or down- regulated genes, we chose highly up- or down- regulated several genes and confirmed its regulation in response to ionizing radiation exposure by RT-PCR analysis. Moreover, we showed that specific co-expression networks of candidate radio marker genes by ARACNE algorithm. Our results present profiles of gene expression related to different ionizing radiation and marker gene to predict sensitivity to ionizing radiation, such as GS (glutelin subunit) and FBX322.

The green rice leafhopper (GRH), Nephotettix cincticeps Uhler, is one of the most serious insect pests affecting cultivated rice (Oryza sativa L.) in temperate regions of East Asia. To understand the genetic basis of the GRH resistance, a F2 population derived from across between a highly resistant variety,Cheongnam and a susceptible variety, Junambyeo was analyzed by genetic analysis and association mapping. GRH resistance was evaluated using the F2 populations. The results showed that a single dominant gene in Cheongnam. DNA from 22 F2 individuals being either resistant or susceptible were pooled to produce bulk resistant and bulk susceptible DNA samples. Parents and bulks were screened with 192 SSR markers and twolinked SSRmarker, RM6082 and RM20145 were identified.Subsequent mapping in the original mapping population showed that thelocusis flanked by the SSR markers, RM20130 and RM20152 on chromosome 6. To physically map this locus, the-linked markers were landed on the artificial chromosome clones of the reference cv., Nipponbare, released by the International Rice Genome Sequencing Project. The DNA markers found to be closely linked to Grh3 would be useful for marker-assisted selection for the improvement of resistance to GRH in rice.

This study was carried out to determine the contents of antioxidant activity of colored rice lines which derived from a mutant of MGI079 induced by MGI079 tissue culture in rice (Oryza sativa L.). The antioxidant activities were evaluated by assaying polyphenol, flavonoid, DPPH free radical and color values of colored rice lines, respectively. Among 8 lines including Heugnam of colored rice, the 70% ethanol extracts decreased in the order of MGI079-2-1>MGI079-2-6>MGI079-2-R,Heugnam>MGI079-1-R>MGI079-2-1>MGI079, MGI079-1-1, MGI079-1-6. The rice lines of highest polyphenolic compound was MGI079-2-6 and the next were Heugnam, MGI079-2-R, MGI079-2-1, MGI079-1-R, MGI079-1-6, MGI079-1-1, MGI079, MGI079-OP-R with the order of higher content. The flavonoid was higher in order of MGI079-2-1, MGI079-2-6, Heugnam, MGI079-2-R, MGI079-1-R, MGI079-1-6, MGI079-OP-R, MGI079, MGI079-1-1. The DPPH free radical was higher in order of MGI079-2-1, MGI079-2-6, Heugnam, MGI079-1-6, MGI079-1-1, MGI079-2-R, MGI079-1-R, MGI079-OP-R, MGI079. For chromaticity, a negative correlation was exhibited between the color value and the 70% ethanol extracts, polyphenolic compound, flavonoid, DPPH free radical. The grain characters in brown rice of a mutant of MGI079 showed similar to that of a donor plant, MGI079. Whereas, chemical characteristics of brown rice in two colored rice lines(MGI079-2-1, MGI079-2-6) were lower in amylose and lipid contents and were higher four times in zinc that of a donor plant, MGI079. Two colored rice lines(MGI079-2-1, MGI079-2-6) showed relatively high antioxidative activity in every results of antioxidant activity tests.

This study investigated the functional substances, including phenolics, tocopherol compounds in rice (Onnuri, Nampyeong, Dongjin, Deuraechan, Hopum, Iksan-515, Iksan-526) that were cultivated in Iksan region. Specially, Iksan-515 and Iksan-526 were produced resveratrol rice. Resveratrol is health-beneficial compound with strong antioxidant activity. Iksan-515 and Iksan-526 were contained resveratrol compound while, other rice varieties did not showed resveratrol. The total phenolic compounds showed similar concentrations in 7 rice varieties. Especially, Iksan-526 revealed 273.3 ㎍ g-1 and Iksan-515 was 264.8 ㎍ g-1. In this study, we analyzed vitamin E contents of 7 varieties of rice. The total tocopherols revealed 418.3 ㎍ g-1 in Iksan-526, 401.2 ㎍ g-1 in Iksan-515 and 413.3 ㎍ g-1 in Hopum. We determined 4 tocopherols (α-, β-, γ-, δ-) and 4 tocotrienols (α-, β-, γ-, δ-). Among the all samples, β-tocotrienol showed higher average concentrations (101.3 ㎍ g-1) than other compounds and, γ-tocotrienol revealed second higher concentration (94.5 ㎍ g-1). On the other hand, δ-tocopherol was not detected in all rice samples.