In order to clarify the chromosomal location of quantitative trait loci (QTL) associated with the yield and agronomic traits in waxy corn and sweet corn (Zea maysL.), we were conducted identifying of QTLs associated with yield and agronomic traits by employing genetic linkage map of F2:3 population. A total of 14 QTLs each for days to silking (DTS), plant height (PH), ear height (EH), ear height ratio (ER), ear length (L-Ear) and kernel setting length (L-Sear) were detected in the 158 F2 families. The number of QTL per each trait was ranged from 1 to 6, and also phenotypic variance was ranged from 3.55 to 16.86%. For DTS, one QTLs was found to be controlled by genomic regions at locations chromosomes 1 contributing 9.21% of phenotypic variance. While three QTLs for PH, were found to be controlled by 3 genomic regions at locations chromosomes 1 and 2 contributing 6.68, 6.85 and 8.17% of phenotypic variance, respectively. For EH, six QTLs were found to be controlled by 6 genomic regions at locations chromosomes 1, 7, 8 and 10 range from 3.55 to 11.44% of phenotypic variance. The one QTLs for ER was found at locations chromosomes 1 contributing 7.25% of phenotypic variance. For L-Ear, two QTLs were found to be controlled by 2 genomic regions at location chromosome 7 and 10 contributing 7.40 and 11.63% of phenotypic variance, respetively. The one QTLs for L-Sear was found at locations chromosomes 3 contributing 16.86% of phenotypic variance. Among them, three QTLs, such as qEH8 (11.44%), qLEar10 (11.63%), and qLSear3 (16.86%) may be considered as a major QTLs, while the remaining 11 QTLs might be regarded as minor QTLs. This study may provide valuable information for the further identification and characterization of genes responsible for agronomic traits in waxy corn and sweet corn.

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 role of an expansin gene (IbEXP1) in the formation of the storage root (SR) was investigated by expression pattern analysis and characterization of IbEXP1-antisense sweetpotato (Ipomoea batatas cv.Yulmi) plants in an attempt to elucidate the molecular mechanism underlying SR development in sweetpotato. Transcript level of IbEXP1 was high in the fibrous root (FR) and petiole at the FR stage, but decreased significantly at the young storage root (YSR) stage. IbEXP1-antisense plants cultured in vitro produced FRs which were both thicker and shorter than those of wild-type (WT) plants. Elongation growth of the epidermal cells was significantly reduced, and metaxylem and cambium cell proliferation was markedly enhanced in the FRs of IbEXP1-antisenseplants, resulting in an earlier thickening growth in these plants relative to WT plants. There was a marked reduction in the lignification of the central stele of the FRs of the IbEXP1-antisense plants, suggesting that the FRs of the mutant plants possessed a higher potential than those of WT plants to develop into SRs. IbEXP1-antisense plants cultured in soil produced a larger number of SRs and, consequently, total SR weight per IbEXP1-antisense plant was greater than that per WT plant. These results demonstrate that SR development was accelerated in IbEXP1-antisense plants and suggest that IbEXP1 plays a negative role in the formation of SR by suppressing the proliferation of metaxylem and cambium cells to inhibit the initial thickening growth of SRs.

Organ size control is a fundamental developmental processes for higher plants as well as a promising target trait for molecular breeding in crop plants. Genetic mechanisms how plant organs grow to a certain size remains still unclear. Here we present the identification and characterization of a genetic mutant, big flower1-1 (bif1-1) in Arabidopsis that exhibits bigger organ size primarily due to increased cell size. Genetic analysis indicated that it is a single, semi-dominant mutation. Phenotypic analysis showed that bif1-1 exerts pleiotropic effects: it caused bigger seed size, bigger seedling, bigger leaf, thicker stem, increased trichome branching, smaller fruit, and bigger pollen. Microscopic analysis suggested that the bigger organ size in bif1-1 mutant is primarily attributed to increased cell size. Gene expression analysis indicated that most of growth-control genes tested were not altered in bif1-1 mutant. Instead, expression of ARGOS and auxin-inducibility of ANT were reduced in bif1-1 mutant. Our ongoing positional on the corresponding gene would not only shed light on the molecular mechanisms how plants adopt final organ size but also provide a promising genetic resource for genetic engineering of flower- and seed-size in crop plants.

Toward molecular understanding of flower senescence/abscission, we have identified a mutant, designated as dea1-1D (dealyed abscission1-1D), with delayed flower senescence/abscission syndrome from activation-tagged pools. Phenotypic analysis revealed pleiotropic effects of dea1-1D mutation including delayed flowering as well as smaller serrated leaves. Genetic analysis showed that it is a dominant mutation. Molecular analysis on the flower senescence syndrome indicated that dea1-1D might define novel regulatory branch of flower abscission, controlling expression of ethylene-responsive AP2 transcription factor. On the contrary, triple responses was not affected by dea1-1D mutant. Though the penetrance was not complete, the mutant phenoytpes was shown to be tightly linked with the T-DNA selection marker, BASTA-resistance. We identified the T-DNA insertion site through molecular cloning of the T-DNA flanking genomic DNA and found that a neighboring gene was overexpressed in the dea1-1D mutant. Together with gene expression analysis, we will discuss possible function of DEA1 during flower senescence and abscission.

The transport of nascent messenger RNA from the nucleus to the cytoplasm is mediated by the THO/TREX complex and is evolutionary conserved from yeast, metazoa and humans. However, in plants, it is still yet unclear if the similar mechanism of transport exists. Here we identified and characterized a mutant gene, AtTHO2, a putative Arabidopsis thaliana THO2 component protein, homologous to yeast THO2 of the THO/TREX pathway required for mRNA transport. The mutation from this gene resulted to various developmental defects that include semi-dwarfism and abnormal floral development which further leads to sterility. Gene expression analysis revealed that AtTHO2 is expressed in all organs and pollen developmental stages. In addition, the homozygote progeny of null mutants did not persist until mature stage. These results suggest an indispensable role of AtTHO2 in the development of Arabidopsis. Differential gen expression and silencing were also observed between the null mutants and wild type depending on T-DNA insertion. Furthermore, alternative splicing which was tightly linked with the THO/TREX pathways was also defective on AtTHO2 and null mutants. A similar pattern of defect in SR34a was observed in the AtTHO2 and null mutants. In terms of microRNA biosynthesis, no significant differences were seen on the wild-type and mutant plants; however this data should be validated. Thus this work provides some evidences that a similar THO/TREX complex exist in plants and gave a foundation for further studies on the mechanism of nuclear export in plants.

The earth has been facing a rapid warming during past several decades. To figure out the impact of high temperature on agronomic performance of rice especially on yield, we cultivated 89 rice varieties of various origin in Suwon Korea, Shanghai China and IRRI Philippines(Wet season and Dry season). Days to heading, culm length, panicle length, panicle number, spikelet number, spikelet fertility, grain weight and grain yield were comparatively investigated. Overall grain yield displayed significantly lower values in Shanghai and IRRI(wet and dry) compared with in Suwon. Meanwhile minimum values were much lower in Shanghai and IRRI than in Suwon. However, some varieties such as Keunseom, Taichung178 showed similar performance for grain yield in both Suwon and IRRI(wet season), and some varieties such as Hangangchal, Dasan showed similar performance for grain yield in Suwon, Shanghai and IRRI(wet season), Nampung showed very high yield in Suwon comparing to other two locations. For most varieties, grain yield was the highest in Suwon and followed by in Shanghai and at IRRI(wet season). However, in dry season at IRRI, yield trend was quite different from the expectation. Further studies are in progress to find out the genotype by environment interactions in order to obtain basic information for breeding high temperature tolerant rice.

A diverse number of genes are involved in the floral transition and development to ensure the proper timing on the switch from vegetative to reproductive development in Arabiodopsis. MADS-box genes play a major role in floral development especially in the case of vernalization process, In this study we mapped a mutation in MAF5 encoding a MADS-domain protein which was reported to be up-regulated during vernalization and regulates flowering time. The mutant in MAF5 showed several pleiotropic phenotypes that includes semi-dwarfism, delayed senescence and abnormal pollen phenotype, High percentages of vacuolated and aborted pollen phenotype were observed in the mutant plant. Transmission efficiency showed that mutation from this gene was defective in both male and female gametes. Furthermore, gene expression analysis revealed that this gene was predominantly expressed in reproductive organs and gave a strong expression in the mature pollen which coincides with the defect in pollen phenotype. The results from this study provide some evidences on the additional role of MAF5 in pollen development however more specific approaches should be done to determine the specific stages of pollen development altered in this mutant.

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.

In this study, we generated and characterized the transgenic rice plant expressing a spider silk protein. A cDNA coding for the C-terminus of spider dragline silk protein (AvDrag) was cloned from the spider Araneus ventricosus. Analysis of the cDNA sequence shows that the C-terminus of AvDrag consists of 165 amino acids of are petitive region and 99 amino acids of a C-terminalnon-repetitive region. The peptide motifs found in spider drag line silk proteins, GGX and An, were conserved in the repetitive region of AvDrag. The AvDrag cDNA was expressed as a 28kDa polypeptide in baculovirus-infected insect cells. To produce transgenic rice plant with high contents of glycine and alanine, the prolamin promoter-driven AvDrag was introduced into rice plant via Agrobacteriumtumefaciens-mediated gene transformation. Because of seeds pecific prolamin promoter, expression of AvDrag protein has been achieved inriceseed. The introduction and copy number of the AvDrag gene in transgenic rice plants were determined by PCR and Southern blot analysis. AvDrag expression in transgenic rice seeds was examined by Northern blot and Western blot analysis. Immuno fluorescence staining with the AvDrag antiserum revealed that the recombinant AvDrag proteins were localized in transgenic rice seeds. Furthermore, the amino acid content analysis showed that transgenic rice seeds were greatly increased in glycine and alanine as compared to controls. The present study is the first to show the expression of spider silk protein in rice seed.

Environmentally inflicted stress (abiotic stress) such as high drought stress could be limiting the plant productivity. The mechanism of drought stress signaling in plant related with anti-apoptosis has not yet been full described. Understanding drought stress signaling is key to producing drought-tolerant plant. In this study we recently have identified Oryza sativa genes related abiotic stress water deficit. Abiotic stress related genes were screened from Oryza sativa cDNA library and identified gene by yeast functional screening. The yeast expression showed that they east cell grow well on SD-galactose-Leu-Ura-. The screening of over than 7000 clones from Oryza sativa cDNA libraries has been identified. 28 clones that survived following BAX-expression on inducible galactose medium. R12H780 clones confirmed protein prediction like putative senescence-associated-protein. This gene contains an open reading frame (ORF) of 108 amino acids. Transcription of R12H780 was induced in response to drought stresses, RT-PCR analysis showed transcript level in plant strongly detected in earliest time of drought stress treatment. Yeast transformed with R12H780 gene displayed markedly improved tolerance to PEG treatment, and high salinity in comparison to the control yeast (vector only). The results indicate R12H780 expression represents a new type of drought stress related gene with anti-apoptotic in Oryza sativa and endows tolerance to several types abiotic stress.

The significance of genetic stability and bio-safety environment has been recently recognized by many GM plants. This study was to evaluate the GM stability of transgenic rice and to identify the environment variance. The GM rice of vitamin A　-enriched rice and four check cultivars were analyzed the data on agronomic characters and principal component for 2009-2011 in large-GM crop field. Cultivation environment was conducted in the large-GM field and greenhouse to determine grain characters. In this experiment, there was no significant difference in agronomic characters between GM rice of vitamin A-enriched rice and a donor plant, Nagdong. Related to grain characters, grain appearance and physicochemical characteristics were similar to GM rice of vitamin A-enriched rice and a donor plant, Nagdong. However, grain appearance in GM rice of vitamin A-enriched rice showed to white core and white belly when GM rice of vitamin A-enriched rice was planted in greenhouse. The type and distribution of dominant weed species also were not different from GM rice of vitamin A-enriched rice and a donor plant, Nagdong. Additionally that of gene flow was not detected in dominant weed species by PCR analysis.

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.

In plants, the Dof (DNA binding with One Finger) proteins are plant-specific transcription factors with a particular class of zinc-finger DNA-binding domain. The Dof genes have been predicted 30 different Dof genes in the rice Oryza sativa genome by phylogenetic analysis. The mostly Dof proteins contain a conserved region of 50 amino acids with a C2-C2 zinc finger motifs that binds a cis-regulatory element sequence 5’-T/AAAAG-3’. We found that a member of the DOF transcription factor family, Dof1 gene of rice, was expressed to wound from Ds insertion mutant population. Sequencing of the flanking regions of the transposon insertion site indicated that the gene-trap had been inserted near the front of the second exon of OsDof1 gene in chromosome 7. Genomic southern analysis revealed that mutant line contained a single copy of Ds gene trap. The Ds tagged rice mutant line, OsDof1::Ds, wound-inducible GUS expression was identified. To analyze the cis-acting elements, we constructed fusion genes with the OsDof1 promoter fused to the β-glucuronidase (GUS) reporter gene and transformed Arabidopsis and rice plants with these constructs. Wound-induced GUS expression was observed in the leaves of transgenic OsDof1::GUS rice and Arabidospsis plants. These results showed that, OsDof1 protein might be involved in stress responses and growth regulation in plant, might plays a role as a transcription regulator in stress response signal transduction pathways of plant.

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.

Transgenic cymbidium plants containing drought and salt stresses tolerance genes were produced by using a highly efficient Agrobacterium-mediated transformation system. The gene (AtSZF2) is salt and drought stresses tolerant gene and transferred into cymbidium plants. These transgenic cymbidium plants are investigated for gene introduction by PCR and analyzed by salt and drought stresses to check its gene expression. To investigate the gene expression of AtSZF2, leaves of transgenic cymbidium plants were soaked in salt solution (200 mM NaCl). Also, transgenic cymbidium plants were kept under no watering for 6 weeks to check the expression of drought stress tolerance. As a result, wild type plants showed more damage than transgenic plants under salt treatment. Further, transgenic cymbidium plants retained green color and healthy status, while wild type plants showed no tolerance after 6 weeks of no-watering treatment.

For purposes of studying intron structures and predicting consensus splice motifs, a total of 102 legume species were used to isolate introns across the family. Of 196 gene-targeted PCR primer pairs, we successfully amplified 118 intron-containing genes (60.2%) and obtained a total of 1,870 introns with an average size of 143 nucleotides. Species-based compilation of 5’- and 3’-splicing motifs showed lineage-specific conservation in each splicing motif. Compilation of the entire intron set permitted prediction of the consensus sequences of splicing signal motifs in legumes, AYGWGTABABGH and TVNC/TAGGHTV for the 5’- and 3’-splicing motifs, respectively. Interestingly, these consensus motifs are very similar to the corresponding splicing signals of two model systems, Arabidopsis and rice. This result is suggestive of conservation of pre-mRNA splicing mechanisms in higher plants. Multiple alignments of CALTL introns demonstrated that the region from the branch point to 3’ splice site was relatively more conserved than the region from5’ splice site to the branch point. Phylogenetic analysis demonstrated that each of three splicing motifs, 5’-splice sites, 3’-splice sits, and branch site, was relevant to evolutionary divergence of species and phylogenetically informative, suggesting that splice signal sequences would be useful as a potential tool for the molecular phylogenetic analysis.

An Arabidopsis small GTPase, RabG3b, was previously characterized as a component of autophagy and as a positive regulator for xylem development in Arabidopsis. In this work, we assessed whether RabG3b modulates xylem-associated traits in poplar in a similar way as in Arabidopsis. We generated transgenic poplars (Populus alba x P. tremula var. glandulosa) overexpressing a constitutively active form of RabG3b (RabG3bCA) and performed arrange of morphological, histochemical, and molecular analyses to examine xylogenesis. RabG3bCA transgenic poplars showed increased stem growth due to enhanced xylem development. Autophagic structures were observed in differentiating xyelm cells undergoing programmed cell death (PCD) in wild type poplar, and were more abundant in RabG3bCA transgenic poplar plants and cultured cells. Xylogenic activation was also accompanied by the expression of secondary wall-, PCD-, and autophagy-related genes. Collectively, our results suggest that Arabidopsis RabG3b functions to regulate xylem growth through the activation of autophagy during wood formation in Populus, as does the same in Arabidopsis.

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.

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.