Recent global warming and climate change has presented greater challenge to the global agriculture of having to cope with more severe adversaries from various abiotic stress conditions including drought, cold, and heat. As a preliminary step towards developing a heat-tolerant japonica rice variety through molecular breeding, we examined and compared expression of several genes that have been reported being expressed specifically during rice panicle development in different rice varieties after subjecting them heat stress. Although the induction of these transcripts upon heat treatment was invariably observed in all rice varieties tested, the magnitude and kinetics of the induction were found to be different among these varieties, suggesting possible functional implication of these genes in conferring heat tolerant phenotype during reproductive organ development of these plants. General protein synthesis activity as well as pollen viability incurred by the heat stress treatment were also monitored in these plants and the result showed a close correlation overall with the induction dynamic of these transcripts under heat stress. Therefore, these genes, together with the ones involved in the regulatory network for the expression of them, could serve as candidates for useful markers with which molecular breeding of heat tolerant japonica rice can be facilitated.

Hybrid sterility is one of the major barrier to the application of wide crosses in plant breeding and is commonly encountered in crosses between indica and japonica rice varieties. Ten mapping populations comprised of two reciprocal F2 and eight BC1F1 populations generated from the cross between Ilpumbyeo (japonica) and Dasanbyeo (indica) were used to identify QTLs and to interpret the gametophytic factors involved in hybrid fertility or sterility between two subspecies. Frame maps were constructed using a total of 107 and 144 STS markers covering 12 rice chromosomes in two reciprocal F2 and eight BC1F1 populations, respectively. A total of 15 main-effect QTLs and 17 significant digenic- epistatic interactions controlling spikelet fertility (SF) were resolved in the the entire genome map of F2 BC1F1 populations . Among detected QTLs responsible for hybrid ferility, four QTLs, qSF5.1 and and qS F5.2 on chromosome 5, qSF6.2 on chromosome 6, and qSF12.2 on chromosome 12 were identified as major QTLs since they were located at corresponding position in at least three mapping populations. Loci qSF5.1, qSF6.1 and qSF6.2 were responsible for both female and male sterility, whereas qSF3.1, qSF7 and qSF 12.2 affected the spikelet fertility only through embryosac factors, and qSF9.1 did through pollen factors. Five new QTLs identified in this study will be helpful for understanding the hybrid sterility and for breeding programs via inter-subspecific hybridization.

Hybrid sterility is one of the major barrier to the application of wide crosses in plant breeding and is commonly encountered in crosses between indica and japonica rice varieties. Ten mapping populations comprised of two reciprocal F2 and eight BC1F1 populations generated from the cross between Ilpumbyeo (japonica) and Dasanbyeo (indica) were used to identify QTLs and to interpret the gametophytic factors involved in hybrid fertility or sterility between two subspecies. Frame maps were constructed using a total of 107 and 144 STS markers covering 12 rice chromosomes in two reciprocal F2 and eight BC1F1 populations, respectively. A total of 15 main-effect QTLs and 17 significant digenic- epistatic interactions controlling spikelet fertility (SF) were resolved in the the entire genome map of F2 BC1F1 populations . Among detected QTLs responsible for hybrid ferility, four QTLs, qSF5.1 and and qS F5.2 on chromosome 5, qSF6.2 on chromosome 6, and qSF12.2 on chromosome 12 were identified as major QTLs since they were located at corresponding position in at least three mapping populations. Loci qSF5.1, qSF6.1 and qSF6.2 were responsible for both female and male sterility, whereas qSF3.1, qSF7 and qSF 12.2 affected the spikelet fertility only through embryosac factors, and qSF9.1 did through pollen factors. Five new QTLs identified in this study will be helpful for understanding the hybrid sterility and for breeding programs via inter-subspecific hybridization.

Two sugary mutants, Hwacheong sugary-1 (Hsu1) and Hwacheong sugary-2 (Hsu2) were obtained by chemical mutagenesis from japonica cultivar, Hwacheongbyeo. Sugary mutants exhibited wrinkled and translucent grain with high soluble sugar content. In addition, amber-colored endosperm of sugary mutants was loosely packed due to abnormal starch granules compared to densely packed wild-type. Especially, the grain of Hsu2 mutant was less wrinkled than that of Hsu1, thus Hsu2 can be polished easily. Previous studies reveal that su1 mutant was resulted from mutation in gene for a debranching enzyme, isoamylase but the sequence of the mutated gene has not been identified. To identify the sequence of sugary genes, the map-based cloning strategy was applied. The genetic study revealed that the phenotype of Hsu2 mutant was controlled by two recessive genes. Interestingly, one of the genes was located on chromosome 8 at the position of isoamylase which was known as su-1. This indicates that mutation in isoamylase gene causes sugary endosperm characteristics. However we found different mutation points between the Hsu1 and Hsu2. The point mutation in Hsu1 was occurred at 10th exon whereas the other mutation related with Hsu2 was occurred at 15th exon. As mentioned above, the Hsu2 mutant has less wrinkled shape and less soluble sugar content than the Hsu1 mutant. Thus, we hypothesize that the other gene controlling Hsu2 mutant phenotype may have a role in weakening the effect of the su-1. Further study on the other gene associated with the Hsu2 phenotype is in progress.

인체피부에서 화장품이나 화장품 원료의 안전성시험은 대체로 육안평가로 이루어져왔다. 하지만, 피부반응 초기의 미세한 변화에 대해서 육안으로는 감지하지 못하는 경우가 많다. 따라서, 본 연구에서는 수종의 화장품 원료에 의해 유발되는 홍반반응에 대해 육안평가뿐 아니라, 레이저도플러혈류이미지(LDPI) 측정장비를 이용한 혈류변화 측정, Vapometer®를 이용한 경피수분손실량(TEWL) 측정, 분광광도계를 이용한 피부색 측정과 같은 기기평가를 병행하여 비교하였다. 30명의 건강한 여성 피험자를 대상으로 오일류 7종, 계면활성제류 6종, 보습제류 5종을 피험자의 등 부위에 24 h 폐쇄첩포(D0)하여 피부반응을 유도하였고 첩포 제거 후 30 min (D1), 24 h (D2)에 육안평가와 기기평가를 각각 실시하였다. 육안평가 결과, 프로필렌글라이콜을 제외한 모든 오일류와 보습제류는 저자극 수준의 피부반응(반응도 0+ ~ 2.9+)을 보인 반면, 프로필렌글라이콜과 모든 계면활성제류는 중자극에서 강자극 수준의 피부반응(반응도 3+ ~ 5+)을 보였다. 기기측정 결과, 육안평가에서 저자극 범주의 피부반응에 대해서 혈류량이나 피부색보다 경피수분손실량이 가장 민감하게 피부변화를 감지하였다.

Leaf structure is one of the important agronomic traits. A rolled leaf mutant was induced from an ethyl methane sulfonate (EMS)-treated japonica rice, 'Koshihikari'. The rolled leaf mutant showed phenotypes of reduced leaf width and leaf rolling. In addition, several abnormal morphological characteristics were observed, including dwarfism, defected panicle, delayed germination, and lower seed-setting. Microscopic analysis revealed that the number of small veins was decreased and the sizes of adaxial bulliform cells were reduced in the mutant leaves. The genetic study with two F2 populations from the crosses of the rolled leaf mutant with 'Koshihikari' and Milyang23 suggested that the mutant phenotype might be controlled by a single dominant gene.

The rice sucrose synthase 3 (RSUS3) localized predominantly inrice seed endosperm may play an important role in the starch filling in the milky stage of rice seed. As the genetic diversity at this locus is not known yet, forty three rice varieties/accessions were objected to amplify full sequence of the RSUS3 to examine the distribution of DNA polymorphisms. A total of 254 sequence variants, including 82, 150 and 22SNP sand indels, were successfully identified in whole length of 7,733bp sequence comprising promoter, exon and intron, and 3’ down stream non transcribed region(NTR). Eleven haplotypes were distinguishable among 43 rice varieties based on the nucleotide variation on the three defined regions (5’NTR, transcript and 3’NTR). The promoter region showed the occurrence of a base change on a cis-element which might involve a functional role of the motif in seed-specific expression. Non random process seemed to be acted in the genetic diversity of RSUS3geneamongricegermplasmusedinthisstudy. The analysis of polymorphism sites indicated a history of eleven minimum recombination mostly occurred in the transcribed region. This result might provide an insight for a clasditic approach for establishing future genetic association studies of RSUS3locus.

Sucrose synthase 3 which is a third active gene present in rice, is localized predominantly in rice endosperm. This sucrose synthase 3 may play an important role in the starch filling in the milky stage rice seed, probably involving in the starch physicochemical properties. As the genetic diversity at this locus is little informed, forty three rice consisting of japonica, indica and Oryza rufipogon were targeted to amplify full sequence of sucrose synthase 3 to examine the frequency and distribution of nucleotide polymorphism. Total of 755 all sequence variants detected, 491 single nucleotide polymorphisms (SNPs) and 264 indels were successfully identified in 7618 bp of sequence containing the sucrose synthase 3 transcript, promoter and 3' non-transcribed region. The frequency of nucleotide changes and indels were high, on average one polymorphism per 15.5 bp and one indel per 28.9 bp with 11 sequence-based haplotypes distinguishable among the varieties and lines. Both the frequency of nucleotide changes and indels were frequent in non-coding region, but rare in coding region. Sequencing a polymorphism region in the promoter showed one base change on one of cis-element from T (CATGCATA to A (CATGCACA) that might implicate in seed specificity. The presence of a high number of haplotype shared by a few varieties indicated a little information on linkage disequilibrium.

The giant embryo(ge) mutation was genetically mapped to chromosome 7 by Koh et al. The ge mutations were analyzed at the morphologic and genetic level by Hong et al. And this publication linked the GE gene as being required for proper endosperm development. Researchers in Dupont cloned the GE gene, sequenced and characterized the ge alleles of the mutants. the three giant embryo mutant lines we obtained by treating MNU to Hwacheongbyeo, a japonica type Korean rice cultivar, differed in their embryo and endosperm size and their embryo/endosperm ratios. We named these alleles affecting the embryo size in rice GE, ge-m, ge, ge-s (GE: the wild type, ge-m: embryo slightly larger than in the wild type, ge: large embryo, ge-s: embryo even larger than in ge). The ORFs and introns of the four different alleles in the GE locus were sequenced and compared with the corresponding sequences in the patent that dupont presented. Each mutant alleles sequence showed a few SNPs in the ORF region. Two SNPs were shared among the three mutant lines and each mutant line hab one or two additional SNPs. Further studies are in progress regarding the GE RNA expression level in each mutant line and the F1 seed phenotypes and allelism relationship among the mutant lines.