Chloroplasts are plant-specific organelles, which have their own genome. Most of the plant chloroplast genomes (CP genome) are highly conserved in terms of its gene contents and genome structures, and they exist in cells with abundant copy numbers. Because of numerous copy numbers, the complete chloroplast sequence assembly pipeline with small amount of whole genome resequencing data, produced by NGS technique, was established in our laboratory. From 14 accessions of cabbage (Brassica oleracea L.) resequencing data produced by Illumina Hi-seq 2000, CP genomes were assembled and compared to each other. 18 sequence variance regions were detected, and 6 HRM(High Resolution Melting curves) markers were developed. Approximately 1 Gb of whole genome sequencing data of 10 Brassica rapa and 2 Brassica napus were also obtained from Institute of Vegetables and Flowers, Chinese Academy of Agricultural Science. With these resequencing data, all CP genomes from these accessions were assembled. Total 27 complete CP genomes of B.oleracea, B.rapa, B.napus, and brassico-raphanus which is a novel allotetraploid species between B.rapa and Raphanus sativus, were compared in sequence level. Phylogenetic analysis based on the comparison revealed that B.rapa could be the maternal species when rapeseeds and brassico-raphanus became allotetraploid species. Additionally, CP genome of B.napus cv.M083 is closer to B.rapa accessions than the other B.napus accessions, thus B.napus could have several different origins.

Mungbean (Vigna radiata) is a fast-growing, warm-season legume crop that is primarily cultivated in developing countries of Asia. We constructed a draft genome sequence of mungbean to facilitate genome research into the subgenus Ceratotropis and to enable a better understanding of the evolution of leguminous species. The draft genome sequence covers 80% of the estimated genome, of which 50.1% consists of repetitive sequences. In total, 22,427 high confidence protein-coding genes were predicted. Based on the de novo assembly of additional wild mungbean species, the divergence of what was eventually domesticated and the sampled wild mungbean species appears to have predated domestication. Moreover, the de novo assembly of a tetraploid Vigna species (Vigna reflexo-pilosa var. glabra) provided genomic evidence of a recent allopolyploid event. To further study speciation, we compared de novo RNA-seq assemblies of 22 accessions of 18 Vigna species and protein sets of Glycine max and Cajanus cajan. The species tree was constructed by a Bayesian Markov chain Monte Carlo method using highly confident orthologs shared by all 24 accessions. The present assembly of V. radiata var. radiata will facilitate genome research and accelerate molecular breeding of the subgenus Ceratotropis.

Olive flounder Paralichthys olivaceus is one of the most widely cultured fish species in Korea. Although olive flounder receive attention from aquaculture and fisheries and extensive research has been conducted eye morphological change in metamorphosis, but little information was known to molecular mechanism and gene expression of eye development- related genes during the early part of eye formation period. For the reason of eyesight is the most important sense in flounder larvae to search prey, the screening and identification of expressed genes in the eye will provide useful insight into the molecular regulation mechanism of eye development in olive flounder. Through the search of an olive flounder DNA database of expressed sequence tags (EST), we found a partial sequence that was similar to crystallin beta A1 and gamma S. Microscopic observation of retinal formation correspond with the time of expression of the crystallin beta A1 and gamma S gene in the developmental stage, these result suggesting that beta A1 and gamma S play a vital role in the remodeling of the retina during eye development. The expression of crystallin beta A1 and gamma S were obviously strong in eye at all tested developing stage, it is also hypothesized that crystallin acts as a molecular chaperone to prevent protein aggregation during maturation and aging in the eye.

R genes are a key component of genetic interactions between plants and biotrophic bacteria and are known to regulate resistance against bacterial invasion. The most common R proteins contain a nucleotide-binding site and a leucine-rich repeat (NBS-LRR) domain. Some soybean NBS-LRR genes have also been reported to function in disease resistance. A total of 319 genes were determined to be putative NBS-LRR genes in the soybean genome. The number of NBS-LRR genes on each chromosome was highly correlated with the number of disease resistance QTL in the 2-Mb flanking regions of NBS-LRR genes. In addition, the recently duplicated regions contained duplicated NBS-LRR genes and duplicated disease resistance QTL, and possessed either an uneven or even number of NBS-LRR genes on each side. The significant difference in NBS-LRR gene expression between a resistant near-isogenic line (NIL) and a susceptible NIL after inoculation of Xanthomonas axonopodis pv. glycines supports the conjecture that NBS-LRR genes have disease resistance functions in the soybean genome. The number of NBS-LRR genes and disease resistance QTL in the 2-Mb flanking regions of each chromosome was significantly correlated, and several recently duplicated regions that contain NBS-LRR genes harbored disease resistance QTL for both sides. In addition, NBS-LRR gene expression was significantly different between the BLP-resistant NIL and the BLP-susceptible NIL in response to bacterial infection. From these observations, NBS-LRR genes are suggested to contribute to disease resistance in soybean. Moreover, we propose models for how NBS-LRR genes were duplicated, and apply Ks values for each NBS-LRR gene cluster.

Next generation sequencing (NGS) approaches can also be useful tool for characterization of organelle genomes. We generated chloroplast (CP) genome sequences of two Korean ginseng cultivars, Chunpoong and Yunpoong, based on reference-guided assembly using whole genome NGS data. We used 0.5x of P. ginseng genome NGS reads to assemble CP genome. Of the NGS reads used, about 6% were mapped to the reference CP genome with mean coverage of 94x due to high copy number of CP genome in plant cell. CP genomes of the two cultivars were predicted to be 156,248 bp and 156,355 bp in length and showed about 0.1% differences at nucleotide level, compared to reference CP genome sequenced from P. ginseng (Acc.no. NC_006290), whereas difference between CP genomes of the two cultivars is very rare. In this study, we developed the molecular marker to perform taxon identification and also to elucidate phylogenetic relationship among Korean ginseng cultivars. Now, we are analyzing the CP genomes of other P. ginseng cultivars together with other Panax species including American ginseng and Panax related species.

Miniature inverted- repeat transposable elements are expected to play vital role in evolution of genes and genome of major eukaryotic organisms. However, there have been little reports on MITEs in B. rapa, a polyploidy model genome. We identified 13 novel MITE families in B. rapa genome by computational approach. Out of 13 MITEs families three, eight and two were classified under stowaway-like, tourist-like and hAT super families based on their unique structural characteristics. We characterized the members of 13 MITE families from the available 256 Mbp from whole genome draft sequences of B. rapa. We found ech MITE has high copiy number ranges from 14 to 977 which are distributed randomly along all the chromosomes. We also found more than 40% of the MITE members were associated with genes and gene rich regions. Furthermore, the polymorphism due to insertion and non-insertion of MITEs analysis suggest that MITEs are active in the genome. As, such the newly identified MITEs will provide a foundation for the further analysis of roles of MITEs in gene and genome evolution.

Chinese cabbage (Brassica rapa ssp. pekinensis) is one of the most important vegetables and widely cultivated in Asia countries including Korea and China. Recently, whole genome sequence and full-length cDNA information of this species became available, which are encouraging genetic studies of this species to characterize agricultural important traits. Orange-colored (Or) cultivar of Chinese cabbage has inner leaves in orange, whereas other cultivars generally cultivated have yellow (Ye)- or white-colored inner leaves. In this study, we investigated phenotypes and carotenoid biosynthesis genes related to color variation in the Or cultivar. Firstly we compared the carotenoid content and composition between the Or and Ye cultivars by HPLC analysis. The inner leaves of Or cultivar contained approximately 9-fold high β-carotene content, whereas content of both lutein and violaxanthin was decreased to less than 30%, compared to Ye cultivar. Or cultivar was segregated with ratio of 3:1 in F2 population derived from crossing between Or and Ye inbred lines, indicating that Or phenotype is controlled by single recessive gene. To identify this gene, we investigated the expression of several genes involved in carotenoid biosynthesis by RT-PCR analysis. Among genes tested, two encoding putative carotenoid isomerase (CRTISO) and phytoene desaturase (PDS) were identified to show different expression between Or and Ye cultivars. Through further analysis of genomic DNA regions of these two genes, we could expect that several mutations such as InDel and base-substitution occurred and then affected expression of these genes in Or cultivar. In this presentation, I will introduce more detailed results for Or cultivars.

family in the Brassica genome sequences by computational approach. The MITE family showed a total of 264bp length including 36bp terminal inverted repeats and remained 2bp (TA) targets it eduplication by its insertion. By searching the genome database of Brassica species, 516, 227, and 15 members were identified from 470Mbp of Brassica oleraceae, 154Mbp of B.rapa and 15Mbp of B.napus, respectively, indicating that there are approximately 692, 760, 1235 copies in B.oleracea, B.rapa and B.napus genomes,respectively. A total of 225 relatively intact MITE members, 146,68, and 11 members, which showed >80% sequence similarity and sequence coverage were identified and retrieved for MITE analysis from B.oleracea, B.rapa and B.napus genomes, respectively. Out of 225 MITE family members 159 having full structure of MITE and 66 having the truncated end either in right TIR or left TIR. Insertion polymorphism due to insertion or non-insertion of MITEs showed high level of polymorphism among accessions intra and inter species of Brassica. The new MITE would provide abetter tool for study molecular breeding in Brassica species and also helpful to understand their contribution in evolution and diversification of the highly duplicated Brassica genome.

Perilla is a genus as a member of the mint family Lamiaceae which is known to contain lots of volatile metabolite. Perilla has been called as ‘deulkae’ indicating ‘wild sesame’ that means it has been maintained in Korea with long history. It has been very friendly used as edible oil and as fresh leaf vegetable. Perilla oil is valued for its medicinal benefit because it contains best amounts of unsaturated fatty acids, especially for the alpha-linolenic acid, known to omega-3 fatty acid, among all of the plant oils. It also include many beneficial phytochemicals. However, little study is conducted on their genetics. Here, we announce construction of well normalized and full length enriched-perilla cDNA library from a whole plant of one cultivar ‘Youngho-deulkae’ and their sequence characterization to provide useful resources for genetics, breeding and metabolite engineering. By sequencing of 5,760 cDNA clones, we 5,438 high quality EST sequences. Sequence trimming and assembly resulted 3,995 unigenes which consists 1,004 contigs and 2,991 singletones. Unigenes that showed little homology at the DNA sequence level with known genes in other plants even though they showed similarity at the protein domain level based on BLASTN, BLASTX, and TBLASTX. This study may provide good resources for initiation of further genomics, comparative genomics, functional genomics such as metabolic engineering and molecular breeding.