This study was carried out to develop expressed sequence tag-Simple sequence repeat (EST-SSR) markers of brown plant hopper resistance gene originated from a rice cultivar ‘Cheongcheong’ and sensitive rice cultivar ‘Nakdong’. Total RNA extracted from the leaves of ‘Cheongcheong’ and ‘Nakdong’ were used to synthesize a cDNA library. As a result of analyzing the cDNA library, EST-SSR sites were found and the EST-SSR primer sets were developed. This study enables to provide effective marker assisted selection (MAS) methods on the selection of white-backed planthopper resistance gene originated from a rice cultivar more simply, quickly and precisely. Furthermore, using this marker’s advantage of deriving from cDNA, it is possible to identity the white-backed planthopper resistance gene.
The plant family chrysanthemum is known for its medicinal, ornamental, and economic purposes. Owing to its economic and biological significance to the difficult identification based on morphological characters, it is useful to develop DNA barcodes. DNA sequence data enable not only the inference of phylogenetic relationships but also provide an efficient method for species-level identifications under terms DNA barcoding or DNA taxonomy. The purpose of this study is to evaluate the utility of DNA barcoding in discriminating Chrysanthemum species. Four cpDNA regions (matK, rpoC, rpoB, trnH-psbA) and one nuclear (ITS) marker have sequenced from 28 specimens of 11 species from 4 genera of Chrysanthemum which were collected from 5 provinces in Korea. Comparisons of within and between species levels of sequence divergence showed that genetic variation between species exceeds variation within species.
The Korean people consume a lot of hot peppers. Despite its popularity and importance, genetic mechanism determining the content of capsaicinoid has not been understood yet. Since the inheritance of capsaicinoid content is thought to be controlled by quantitative trait loci (QTLs), a well-constructed genetic population and well-organized approach method to study genetic inheritance are required. Here we show the scheme to find the QTLs controlling capsaicinoid content using a recombinant inbred lines (RILs) obtained from a cross between C. annuum, Perennial and C. annuum, Dempsey. We measured capsaicinoid contents of each line for QTL analysis. In addition, total 24 qualitative and quantitative traits of RILs were phenotyped. Phenotyping data can be used to construct another QTL map controlling agricultural trait. An ultra high density linkage map constructed by sequencing RILs will used for QTL nalaysis. We are expecting that this study will be useful to breed high-quality and pungent pepper cultivars by molecular breeding method.
Genetic map provides basic and important informations for breeding. Therefore, genetic map construction is a essential process in plant research. Panax ginseng is one of the most famous medical plant in the world. However, genetic informations of this medical plant for breeding are not enough. Because of little informations, genetic map construction of panax ginseng provides very useful information for breeding. Using Solexa next generation sequencing (NGS) technology, we have been produced a lot of expressed sequence tags (ESTs) and whole genome sequences from Chunpoong (368 Gb) and Yunpoong (6 Gb) cultivar. To develop large amount of DNA markers and thus construct high resolution genetic map, we inspect large scale of SSR motif and putative SNP sites which can be used as dCAPs markers using produced ginseng’s sequence data. As a result, we can find a number of DNA markers that have polymorphism between Yunpoong and Chunpoong cultivar. These developed DNA markers were analyzed for F2 population of Yunpoong x Chunpoong to find markers showing Mendelian segregation ratio 1:2:1.
Radish, Raphanus sativus L., is an annual vegetable of the family Cruciferae. Radish has RR genome with 18 somatic chromosome numbers (2n=2x=18). Until now, detailed karyotypic analysis is not only constructed only by conventional staining techniques but also other method. Fluorescence in situ hybridization (FISH) is a powerful molecular cytogenetic technique using chromosomal markers that reveal the positions of specific genes, such as ribosomal DNAs, thereby making it easy to identify individual chromosomes. We have constructed detailed karyotypes of four different local and wild varieties of radish, based on the chromosome arm length and fluorescence in situ hybridization (FISH) with the 45S rDNA and 5S rDNA as probes. As for the karyotype of radish, 9 pairs of chromosomes were extremely small in size with about 1 to 3 um in length at mitotic metaphase having metacentrics or submetacentrics. Three pairs of 45S rDNA signals and two pairs of 5S rDNA signals were observed in four radish species. One pair of 45S rDNA signal was located on terminal region of short arm chromosome, while two pairs were in interstitial region. Two pairs of 5S rDNA signals were located on interstitial region of chromosome. In conclusion, it was feasible to identify the radish by karyotype and physical mapping analyzed using ribosomal DNA.
As soybean (Glycine max) is known for its high nutritional value of oil and protein, soybean has been domesticated and cultivated by one specific character trait based on human selection. Importantly, tracing back in time where G. max and G. soja, the undomesticated ancestor of G. max have diverged plays an important role in studying of genetic diversity and in investigating the common ancestor of soybean. In this study, we sequenced 6 G. max and 6 G. soja using Illumina’s Hiseq 2000 with a low coverage sequencing technology to estimate the divergence of times between genotypes and populations. A total of the 12 genotypes were sequenced at the average depth of 6.5 and resulted 892.5 Mb and 903.3 MB consensus sequences with the coverage of 91.54% and 92.65% for G. max and G. soja, respectively. The whole genome SNP analysis showed that G. max had lower frequency levels of polymorphism (~0.1%) than G. soja (~0.25%). And, a high number of SNPs located in introns were found among 6 G. soja genotypes as SNPs were approximately twice than those found in 6 G max. The number of SNPs in G. max intronic regions was 53,134, whereas a total of 133,329 SNPs were discovered in G. soja introns. Almost an equal number of SNPs were discovered in 5’ UTR and exon regions; however, different numbers of SNP in CDS and 3′ UTR were identified. By the rate of nonsynonymous change, divergence of time between G. soja and G. max would be investigated.
The antimicrobial peptide possesses defence system to virus, fungi and bacteria. To study antibiotic in plant, antimicrobial peptides were obtained by PCR analysis by primers designed from antimicrobial peptides (Gene bank accession no. NM-004345), cloned in pET28 expression vector and the vector transformed into E. coli. And this gene was inserted into Ti-plasmid VB2 vector, which contained the pGD1 promoter. The expression construction was transformed into Agrobacterium EHA105 and then plant tissues of rice (Oryza sativa). Seeds from transgenic plants (T0) were germinated on selective media containing spectinomycin 50 mg/L. Selected plants and wild type were analyzed by PCR and RT-PCR with pGD1 promoter region and transgene specific primer set. All transgenic plants showed expression pattern of similar levels. We showed that the chromobody is effective in binding GFPand antimicrobial peptide gene in tobacco leaf. Most interestingly, this can be applied to interfere with the function of GFP fusion protein and to mislocalize (trap) GFP fusions to the plant cytoplasm in order to alter the phenotype mediated by the targeted proteins. Bacterial blight disease was enhanced resistance in transgenic lines. These results showed that antibiotic peptides might show a broad-spectrum antimicrobial activity.
eIF4E family is well known for recessive resistance gene of potyvirus in many crops. And Turnip mosaic virus (TuMV) is one of the major viruses in Brassicaceae crops which belong to the genus Potyvirus. To elucidate the key amino acids in the interaction between TuMV VPg and Brassica eIF(iso)4E, amino acids of eIF(iso)4E were mutated. Seven amino acids in cap binding pocket were chose for the candidate amino acid that may play a role in the interaction of TuMV VPg. We demonstrated that a single amino acid mutation in cap binding pocket of Brassica eIF(iso)4E can abolish the interaction with TuMV VPg. eIF(iso)4E which has a mutation at each W49, W95 and K150 positions impaired in its interaction with VPg prominently according to the yeast two hybrid analysis. Complementation of an eIF4E knockout yeast strain by mutated eIF(iso)4E proteins showed that all eIF(iso)4E mutants were able to complement eIF4E of yeast. To find out if these mutations affect the susceptibility of Chinese cabbage, transformant analysis was performed. eIF(iso)4E W95L, W95L/K150E and susceptible wild type were over-expressed in susceptible Chinese cabbage. According to the TuMV screening result of T1 and T2 transformants, over-expression of the eIF(iso)4E mutants showed resistance to four TuMV strains (CHN2, 3, 4 and 5). Our results support that the mutations in eIF(iso)4E may control the broad spectrum TuMV resistance.
Wheat is the third largest crop in the world behind corn and rice. Wheat is grown over a wide range of environments, and an essential source of carbohydrates. However, the genomics of wheat, a non-model species, is still challenging despite of corn and rice was done. The recent advent of RNA-Sequencing, a massively parallel sequencing method for genome and transcriptome analysis, provides opportunity to identify gene discovery and molecular mechanisms of cellular processes. We performed a RNA-Seq experiment to find differentially expressed genes under high temperature condition. More than 344 million shot reads were generated using Illumina HiSeq technology. A comprehensive and integrated 285,324 transcripts were assembled via Trinity by combining tentative consensus sequences. Transcripts annotated by BLAST2Go and differently expressed transcripts were analyzed. A total of 208 up-regulated and 182 down-regulated transcripts were found that involve in plastid, starch and sucrose metabolism, glycerolipid metabolism and glycerolipid and dicarboxylate metabolism. Our results demonstrate that RNA-Seq can be successfully used for gene identification, transcript profiling in wheat. Furthermore these sequences will provide valuable resources for wheat researchers.
Here, we first demonstrate that identification of rice brown spot disease fungus (Cochliobolus miyabeanus, C. miyabeanus) proteins is possible in infected tissues using in planta apoplastic proteome with non-destructive tissues. In planta apoplastic proteins from rice leaves inoculated with C. miyabeanus, CM2 (compatible race), were isolated by vacuum infiltration with CaCl2/Na-acetateextractionbuffer, separated by SDS-PAGE, and identified by MudPIT. Of the 529 proteins that were identified by MudPIT, a large proportion (490) was from the rice. Numerous carbohydrate metabolic process (48), oxidation and reduction (44), response to oxidative stress (20%) were identified and confirmed their expression at RNA levels using microarray. Bioinformatic analysis showed that 176 and 39 of these proteins have a signal peptide in rice and rice brown spot fungus, respectively, using Signal P. The large proportion of proteins interestingly identified from the in planta apoplast were involved inprotease, hydrophobin, and host cell wall hydrolysis (Xylanase, beta-glucosidase) derived from pathogen. Thus, we suggest that in planta rice apoplastic secretome will be an important clue to understand the rice-rice brown spot fungus interactions.
We investigated the expression patterns of a granule-bound starch synthase I (GBSSI = Waxy) gene at different developmental stages of storage and non-storage organs in Amaranthus cruentus. GBSSI transcripts were strongly expressed in the middle and mid-late stages of seed development and thereafter expression decreased. In addition, this gene was expressed in all non-storage organs tested (the leaf, stem, petiole and root) and showed a tendency to increase during plant development. Therefore, our results indicate that the amaranth GBSSI gene exhibits late expression in the perisperm, and that it is expressed in both storage and non-storage tissues. We also investigated the genetic diversity of GBSSI among 37 strains of amaranth grains originating from New World. A comparison of the GBSSI coding sequence revealed an extremely high level of sequence conservation, and a single nucleotide polymorphism between the sequences of non-waxy (Type I) and waxy (Type II) phenotypes was detected. This indicates that a G–T polymorphism in exon 10 (a nonsense mutation) was a unique event in the evolution of the GBSSI gene in amaranth grains.
A core genetic map of the legume Medicago truncatula has been established by analyzing the segregation of 288 sequence-characterized genetic markers in an F2 population composed of 93 individuals. These molecular markers correspond to 141 ESTs, 80 BAC end sequence-tags, and 67 resistance gene analogs, covering 513 cM. In the case of EST-based markers we used an intron-targeted marker strategy, with primers designed to anneal in conserved exon regions and amplify across intron regions. Polymorphisms were significantly more frequent in intron vs exon regions, thus providing an efficient mechanism to map transcribed genes. Genetic and cytogenetic analysis produced eight well-resolved linkage groups, which have been previously correlated with eight chromosomes by means of FISH with mapped BAC clones. We anticipated that mapping of conserved coding regions would have utility for comparative mapping among legumes; thus 60 of the EST-based primer pairs were designed to amplify orthologous sequences across a range of legume species. As an initial test of this strategy, we used primers designed against M. truncatula exon sequences to rapidly map genes in Medicago sativa. The resulting comparative map, which includes 68 bridging markers, indicates that the two Medicago genomes are highly similar, and establishes the basis for a “Medicago” composite map.
In order to improve rice dough functionality, we cloned 4 kinds of high-molecular-weight glutenin subunit (HMW-GS) genes from bread wheat, ‘Jokyeong’. Among them, we first examined Dx5 gene to generate marker-free transgenic rice for advanced quality processing of bread and noodles. The GluB1 promoter was inserted into binary vector for seed specific expression of the Dx5 gene. Two expression cassettes comprised of separate DNA fragments containing only the high-molecular-weight glutein subunit (HMW-GS) protein (Dx5) and hygromycin phosphotransferase II (HPTII) resistance genes were introduced separately to tumefaciens EHA105 strain for co-infection. Each EHA105 strain harboring Dx5 or HPTII was infected to rice calli at 3: 1 ratio of Dx5 and HPTII, respectively. Then among 66 hygromycin-resistant transformants, we obtained two transgenic lines inserted both with Dx5 and HPTII gene to rice genome. We reconfirmed integration of the Dx5 and HPTII genes into the rice genome by Southern blot analysis. Wheat Dx5 transcriptsin rice seeds was examined with semi-quantitative RT-PCR. Finally, the marker-free plants containing only Dx5 gene were successfully screened at T1 generation. This result also provides that co-infection system with two expression cassettes could be efficient strategy to generate marker-free transgenic rice plants.
Gene expression profiles can serve as a valuable reference for deciphering gene functions. We exploited the potential of whole genome microarrays to measure the temporal expression profiles of rice genes in 13 stages of reproductive development. We could profile expression of 17,676 genes in at least one of the tissues. Differential expression analysis with compare to leaf and preceding stages of development revealed reproductive stage-preferential/-specific genes. we identified 35 genes expressing specifically during panicle and seed development. The metabolic/hormonal pathways and transcription factor families playing key role in reproductive development were elucidated after overlaying the expression data on the public databases and manually curated list of transcription factors, respectively. During floral meristem differentiation (P1cm) and male meiosis (P5cm), the genes involved in jasmonic acid and gebbellin biosynthesis were significantly upregulated. F11DAP stage of seed, containing enlargement organ, exhibited enrichment of transcripts involved in starch or sucrose biosynthesis. Genes regulating auxin biosynthesis were induced during early seed development. We validated the stage-specificity of regulatory regions of two panicle-specific genes, AK072471, Os08g0538700, and AK121412, an early seed-specific gene, in transgenic rice. The data generated here provides a snapshot of the underlying complexity of the gene networks regulating rice reproductive development.
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.
Phosphorus is one of the macronutrients essential for plant growth and development, as well as crop productivity. Many soils around the world are deficient in phosphate (Pi) that plants can utilize. To cope with the stress of Pi starvation, plants have evolved many adaptive strategies, such as changes of root architecture and enhanced Pi acquisition form soil. To understand molecular mechanism underlying Pi starvation stress signaling, we characterized the activation-tagged mutant showing altered responses to Pi deficiency compared to wild type Arabidopsis and named hsp3 (hypersensitive to Pi starvation3). hsp3 mutant exhibits enhanced phosphate transporter activity, resulting in higher Pi content than wild type. However, in root architectural change under Pi starvation, hsp3 shows hyposensitive responses than wild type, such as longer primary root elongation, lower lateral root density. Histochemical analysis using hsp3 mutant expressing auxin-responsive DR5::GUS reporter gene, indicated that auxin allocation from primary to lateral roots under Pi starvation is aborted in hsp3 mutant. Molecular genetic analysis of hsp3 mutant revealed that the mutant phenotype is caused by the lesion in ENHANCED SILENCING PHENOTYPE4 (ESP4) gene whose function is proposed in mRNA 3’ end processing. Here, we propose that mRNA processing plays a crucial role in Pi homeostasis in Arabidopsis.
The Cmr1 gene in peppers confers resistance to Cucumber mosaic virus isolate-P0 (CMV-P0). Cmr1 restricts the systemic spread of CMV-Fny, whereas this gene cannot block the spread of CMV-P1 to the upper leaves, resulting in systemic infection. To identify the virulence determinant of CMV-P1, six reassortant viruses and six chimeric viruses derived from CMV-Fny and CMV-P1 cDNA clones were used. Our results demonstrate that the helicase domain encoded by CMV-P1 RNA1 determines susceptibility to systemic infection. To identify the key amino acids determining systemic infection with CMV-P1, we then constructed amino acid substitution mutants. Of the mutants tested, amino acid residues at positions 865, 896, 957, and 980 in the 1a protein sequence of CMV-P1 affected the systemic infection. Virus localization studies with CMV-GFP clones and in situ localization of virus RNA revealed that these four amino acid residues together form the movement determinant for CMV-P1 movement from the epidermal cell layer to mesophyll cell layers. Quantitative real-time PCR revealed that CMV-P1 and a chimeric virus with four amino acid residues of CMV-P1 accumulated more genomic RNA in inoculated leaves than did CMV-Fny, indicating that those four amino acids are also involved in virus replication. These results demonstrate that the helicase domain is responsible for systemic infection by controlling virus replication and cell-to-cell movement. Whereas four amino acids are responsible for acquiring virulence in CMV-Fny, six amino acid (positions at 865, 896, 901, 957, 980 and 993) substitutions in CMV-P1 were required for complete loss of virulence in ‘Bukang’.
The latest report on draft genome of Brassica rapa sequence has been published. To elucidate the functions of a large population of these genes and to search efficiently for agriculturally useful genes, the Full-length cDNA Over-eXpressor (FOX) gene hunting system was used. The FOX library was transformed into rice by Agrobacteriummediated transformation. Approximately 1,150 FOX-rice lines were generated. Genomic PCR analysis indicated that the average length of FL-cDNAs was 900∼1,200 bp with functional annotation of many unknown function (35.5%). Most of the randomly selected transgenic rice lines showed overexpression (92%) and barely mRNA expression in the wild type Gopum. Moreover, 94% of the 850 transgenic rice lines were moderately tolerant (slightly yellow) to cold and 9 lines were tolerant (seedling light green). For the salinity evaluation, most of the transgenic lines (85%) were highly susceptible whereas seven lines were tolerant. In addition, morphological evaluation of rice lines showed minimal phenotypic alteration (12%). About 25.1 and 22% were earlier in terms of days to heading and chlorophyll contents, respectively. Further, 18% of FOX rice lines showed lower chlorophyll contents. Filled grains, number of tillers, panicle length, culm and plant height were relatively less variable among the lines. These results provided useful genes for functional analyses in the mechanisms of identified transgenic tolerant lines.
Advances in genome sequencing technologies have aided discovery of millions of genome-wide DNA polymorphisms, single nucleotide polymorphisms (SNPs) and insertion-deletion (InDels), which are an invaluable resource to analyze genetic diversity in a population. We performed whole-genome resequencing of ten Korean rice accessions including six cultivars and four mutant lines. A total of 2,447 million raw reads were generated with over 58x coverage and detected 3,240,025 DNA polymorphisms between the Korean rice accessions and Nipponbare as reference genome. We observed that in ten Korean rice accessions, the frequency of potential SNPs was estimated to be one per 2.1kb on Nipponbare (382Mb). Potential SNPs were classified into two types, homozygous SNP and heterozygous SNP, which approximately 87% of the total was homozygous SNPs from ten accessions and heterozygous SNPs accounted for 13%. According to annotation of DNA polymorphisms, 634,620 SNPs were found in gene region, and only 169,738 SNPs were occurred in coding region. Altogether, 86,251 non-synonymous SNPs were located on 76,891 genes. We also examined genes which had at least one SNP in all ten accessions. It was estimated that the total of 290 genes had one or more non-synonymous SNPs and 25 genes had only synonymous SNPs. These genes were functionally classified based on gene ontology (GO). These DNA polymorphisms obtained from our result will provide an invaluable resource to identify molecular markers and genes associated with diverse traits of agronomical importance.
Panax ginseng is a well-known herbal plant originated from North-east asia for its various tonic effects. However, production of ginseng roots takes long time in field condition, usually five through six years until harvest. Additionally, ginseng is very susceptible to many kinds of biotic and abiotic stresses, for example, Rhizoctonia solani, which causes damping-off, or high temperature. To overcome these limits, induction of adventitious roots has been studied for more than 10 years and also adventitious roots are widely used materials for genetic research of P.ginseng. In this study, we induced adventitious roots from registered Korean ginseng cultivars and cultured them in bioreactor condition. Induction rate of adventitious roots from nine Korean ginseng cultivars was evaluated and growth pattern of four cultivars in bioreactor scale was also studied. Furthermore, genes that are related to biosynthesis of saponins in ginseng, ginsenoside, were discovered in ginseng whole-genome shotgun sequences for genetic research.