Although melatonin biosynthetic genes from plants have been cloned, the melatonin catabolism mechanisms remain unclear. To clone the genes responsible for melatonin metabolism, we ectopically expressed 35 fulllength cDNAs of rice 2-oxoglutarate-dependent dioxygenase (2-ODD) in Escherichia coli and purified the corresponding recombinant proteins. In vitro 2-ODD assays showed four independent 2-ODD proteins that were able to catalyze melatonin into 2-hydroxymelatonin, exhibiting melatonin 2-hydroxylase (M2H). These M2H proteins had peak activities at pH 8.0 and 30°C. The Km ranged from 121 μM to 371 μM with the Vmax ranging from 1.7 to 18.5 pkat/mg protein, respectively. The M2H enzyme activities were dependent on cofactors such as α-ketoglutarate, ascorbate, and Fe2+, similar to the 2-ODD enzymes. M2H activity was inhibited by prohexadione-Ca, an inhibitor of 2-ODD, in a dose-dependent manner. M2H activity was high in the roots of rice seedlings, concurrent with high transcription levels of 2-ODD 21, suggesting that 2-ODD 21 was a major gene for M2H activity. Analogous to the high M2H activity in the roots, 2-hydroxymelatonin was found in large quantities in roots treated with melatonin. These results suggest that melatonin was metabolized into 2-hydroxymelatonin by the M2H genes in plants, but the physiological significance of 2-hydroxymelatonin remains to be examined in the future.

Rice bran has been reckoned as a potential source of edible oil contained 15-20 % of oil, in its natural state, also contains several constituents of potential significance in diet and health. Interest has focused primarily upon gamma-oryzanol, tocotrienols, and tocopherols, all of which demonstrate antioxidant properties. We analyzed the transcriptome profiles for rice grain from high and low oil content lines at the early milky stage using the Illumina sequencing method. This analysis indicated that many transcripts showed different expressions level between high and low oil content rice. The functional classification of those genes indicated their connection with various metabolic pathways, oil transport, signal transduction, transcriptional regulation, and other processes. The results obtained here will enable to understand how changes in oil concentration or availability are interpreted into adaptive responses in early milky stage of rice. Based on the functional annotation of the differentially expressed genes, the possible processes that regulate these expressed transcripts in rice grain was further analyzed. The candidate transcripts may provide genetic resources that may be useful in the improvement of oil contents of rice.

Although the overall structure of the chloroplast genome is generally conserved, a number of sequence variations have been identified, which are valuable for plant population and evolutionary studies. Here, we constructed a chloroplast variation map of 30 landrace rice strains of Korean origin, using the Oryza rufipogon chloroplast genome (Genbank: NC_017835) as a reference. Differential distribution of single nucleotide polymorphisms (SNPs) and indels across the rice chloroplast genome is suggestive of a region-specific variation. Population structure clustering revealed the existence of two clear subgroups (indica and japonica) and an admixture group (aus). Phylogenetic analysis of the 30 landrace rice strains and six rice chloroplast references suggested and supported independent evolution of O. sativa indica and japonica. Interestingly, two “aus” type accessions, which were thought to be indica type, shared a closer relationship with the japonica type. One hypothesis is that “Korean aus” was intentionally introduced and may have obtained japonica chloroplasts during cultivation. We also calculated the nucleotide diversity of 30 accessions and compared to six rice chloroplast references, which shown a higher diversity in the indica and aus groups than in the japonica group in lower level substitution diversity.

BADH1 and BADH2 are two homology genes, encoding betaine aldehyde dehydrogenase in rice. In the present study, we scanned BADHs sequences of 295 rice cultivars, and 10 wild rice accessions to determine the polymorphisms, gene functions and domestication of these two genes. A total of 16 alleles for BADH1 and 10 alleles for BADH2 were detected in transcription region of cultivars and wild species. Association study showed that BADH1 has significant correlation with salt tolerance in rice during germination stage, the SNP P11483(T/A)ishighlycorrelatedwithsalttoleranceindex(STI)(P<10-4). While, BADH2 was only responsible for rice fragrance, of which two BADH2 alleles (P23036, P25390) explain 97% of aroma variation in our germplasm. It indicated that there are no overlapping functions between the two homology genes. In addition, a large LD block was detected in BADH2 region, however, no large LD blocks in a 4-Mb region of BADH1. Only BADH2 region shown significant bias Tajima’s D value from the balance. Extended haplotype homozygosity study revealed fragrant accessions had a large LD block that extended around the mutation site (P23036) of BADH2, while both of the BADH1 alleles (SNP P11483(T/A)) did not show large extended LDblock. All these results suggested that BADH2 was identified as a domesticated gene during rice evolution, while BADH1 was not selected by human beings.

Zinc (Zn) deficiency is one of the important abiotic factors limiting rice productivity world-wide and also a widespread nutritional disorder affecting human health. Zinc is one of the most important essential micronutrient for human About thirty percentage world’s population doesn’t still get enough zinc through their diets. As a staple food of over half world’s population, rice should take the responsibility to provide much more zinc in the future. We analyzed the transcriptome profiles for rice grain from high zinc content and low zinc content lines at the early milky stage using the Illumina Sequencing method. The analysis results for the sequencing data indicated that many transcripts showed different expressions between high zinc content and low zinc content in early milky stage of rice and RT-qPCR analyses confirmed the expression patterns of selected transcripts. Functional analysis of the differentially expressed transcripts indicated that genes have functional annotation and their functions are mainly involved in oxidation-reduction, metabolic, transport , transcript regulation, defense response and photosynthetic processes. Based on the functional annotation of the differentially expressed genes, the possible process that regulates these differentially expressed transcripts in rice grain responding to Zinc at the early milky stage was further analyzed. The functional classification of those genes indicated their connection with various metabolic pathways, Zinc transport, signal transduction, transcriptional regulation, and other processes related to growth and development in early milky stage of rice. Using Illumina sequencing technology, the differences between the transcriptomes of high zinc content and low zinc content lines the early milky stage was described here for the first time. The candidate transcripts may provide genetic resources that may be useful in the improvement of Zinc concentration of rice. The model proposed here is based on differences in expression and transcription between two rice lines. In addition, the model may support future studies on the molecular mechanisms underlying plant responses to Zinc.

In the rice inflorescence development, timing of inflorescent meristem abortion, conversion of the rachis branch meristem to the terminal spikelet meristem and shift to lateral meristem identity determine the overall architecture of the rice panicle (keda-Kawakatsu et al. 2009). Cheng et al. (2011) reported that quantitative trait loci (QTLs) have major effects on panicle apical abortion in rice. However, there have been very few reports about panicle tip mutants. Therefore, this research is conducted to fine map mutant gene and perform functional analysis of mutant gen. Hwacheongbyeo (japonica rice) seed was treated with ethyl methane sulfonate (EMS) for inducing mutation. Two F2 population (Japanica mutant crossed with wild type and Japanica mutant crossed with Milyang 23, Indica type) were established for Phenotyping and genomic analysis. STS markers in crop molecular Breeding laboratory. Additional STS markers for fine mapping were developed based on the Nipponbare genome sequence (http://rgp.dna.affrc.go.jp/blast/runblast.html). All F2 generations showed the segregation of normal plants and mutant following a ratio of 3:1 suggesting the mutant phenotype is caused by a single recessive gene. Initial BSA test made using STS markers confirmed the mutant gene is found in the long arm of chromosome 8. Panicle tip mutant gene, pnt has pleotropic effect which has been manifested in significant reduction of tiller development starting from late stage of vegetative growth and pronounced effect on possession of stay green nature of the rice during the vegetative stage of development. The only significant difference observed within panicle traits is the number of spikelet on primary branch and spikelet fertility. The first primary branch which contain aborted spikelet and elongated distance between spikelet is the most affected structure in the panicle.

For understanding the genetic diversity and genetic relationship between cultivated and weedy types, we evaluated genetic variation of 80 accessions of rice (O. Sativa). This included 42 cultivated accessions and 38 weedy accessions with the help of AFLP and CACTA-TD. A total of 542 loci were analyzed (255 for AFLP and 287 for CACTA-TD) of which AFLP markers exhibited 75% of polymorphism and transposon based CACTA-TD markers exhibited 93% of polymorphism. The average genetic diversity value for all 80 accessions, using AFLP markers was 0.226 (Cultivated – 0.210; Weedy 0.241) and based on CACTA-TD markers was 0.281 (Cultivated – 0.294; Weedy 0.269). A UPGMA phylogenetic tree revealed three major groups for both the marker system. The average polymorphic content value obtained with AFLP and CACTA-TD markers were 0.21 and 0.232, Effective multiplex ratio (AFLP – 47.50; CACTA-TD – 66.75), Marker Index (AFLP – 9.94; CACTA-TD – 21.13) and Resolving power (AFLP – 19.53; CACTA-TD – 34.62) indicated that the CACTA-TD markers were relatively efficient than AFLP markers.

본 연구에서는 밀양23호의 배경에 O. glaberrima의 특정 염색체단편을 가지는 55 이입계통의 내건성 관련 형질을 조 사하여 변이를 검정하고 내건성이 향상된 4 계통을 선발하였 다. 특히 IL55는 유묘기, 영양생장기 그리고 생식생장기에서 반복친인 밀양23호에 비해 조사된 내건성 형질에서 우수한 특성을 보였으며 내건성 관련 유전자의 분석 및 교배모본으 로 이용될 수 있을 것이다. 이입계통들은 밀양23호의 유전적 배경에 각 계통마다 서로 다른 O. glaberrima 단편이 이입된 계통으로, 이 집단은 O. glaberrima에서 유래된 내재해성 및 작물학적으로 유용한 유전자의 탐색에 효율적인 도구가 될 것이다.

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.

Rice mesocotyl is the region between the coleoptile node and point of union of the culm with the root. The mesocotyl is one of the important factor contributing to rice seedling emergence from soil in direct seedling. Several quantitative trait loci (QTLs) for mesocotyl elongation of rice had been reported in few studies. However, association mapping of mesocotyl elongation QTL was not conducted. For that reason, we detected QTLs for mesocotyl elongation in agar and soil conditions and confirmed the potentials of QTLs using chromosome substitution lines (CSSLs). Backcross inbred line (BILs) and chromosome segment substitution lines (CSSLs) derived from a cross between Kasalath and Nipponbare were employed to detect QTLs for mesocotyl elongation in rice. A total of 12 QTLs for mesocotyl elongation were detected on chromosome 1, 3, 6, 7, 9 and 12 using 98 BILs in agar and soil conditions. Two QTLs, qMel-1 and qMel-3 were consistently detected in both conditions. For substitution mapping of qMel-1 and qMel-3, across was made between 2 CSSLs, CSSL-6 and CSSL-15. Our results showed that the qMel-1 was located between two markers RM5448 and RM5310 on chromosome1 and the qMel-3 was located between RM15859-RM15974 on chromosome3. To understand factors controlling mesocotyl elongation, cell expansion and division of rice mesocotyl were investigated. Moreover, microarray analysis was conducted to select candidate genes using near-isogenic lines for two QTLs. 194 genes were up- and down regulated in rice mesocotyl.

Abiotic environmental stresses cause serious economic losses in agriculture. These stresses include temperature extremes, high salinity and drought. We identified several drought stress-related novel/function unknown coding transcripts (transcription factors and functional genes) and non-coding transcripts (small noncoding transcripts such as microRNA and long noncoding transcripts) using the next generation sequencing method from rice (Oryza sativa L.), and have constructed databases of drought stress-related coding and noncoding transcripts. We used novel gene prediction programs for the selections. The expression level of the each gene was analyzed by real-time PCR. The results ended up the selection of 29 transcription factors, 6 microRNAs and 10 long noncoding RNAs. Currently, we are further characterizing these transcripts. We expect that this study could provide functional information of the drought stress-regulated novel genes, and relationships among novel coding and noncoding transcripts.

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.

Drought stress is one of the major stress affecting growth and productivity in rice. Drought tolerance is a complex trait governed by quantitative trait loci (QTLs) making it difficult to understand mechanisms underlying it. We generated a set of 55 introgression lines via a backcrossing using Milyang23, a Korean Tongil-type rice variety as the recurrent parent and O. glaberrima (IRGC Acc. No. 103544), an exotic collection from Mali, West Africa as donor parent. 141 SSR markers were used to genotype 55 introgression lines. The 55 introgression lines with the Milyang23 were evaluated for physiological traits such as Fresh shoot weight (FSW), Fresh root weight (FRW) and Dry shoot weight (DSW) under control and 20% PEG-treated condition. Three lines (IL9, 12, 55) showing significant difference with Milyang23 were selected. The genetic background of the three lines were similar to Milyang23 and it has four, four and two O. glaberrima homozygous segments, respectively. IL9 performed better than Milyang23 in all traits measured in the 20% PEG-treated condition. IL9 possessed four O. glaberrima introgressions on chromosomes 1, 2, 6 and 7. IL12 performed better than Milyang23 in FSW and FRW. IL12 contains four O. glaberrima introgressions on chromosomes 3 and 6. And IL55 contains two O. glaberrima introgressions on chromosomes 2 and 6. O. glaberrima segment delimited by markers OSR19-RM225 at chromosomes 6 was commonly present in these three lines. This region corresponds to the QTL region for drought tolerance reported by other previous studies. A set of introgression lines are being developed containing only few chromosomal segments from O. glaberrima in the Milyang23 background. These would be useful not only in developing drought tolerant lines in the breeding program but also in fine-mapping the genes/QTLs for drought resistance.

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.