• Korean Journal of Plant Tissue Culture
• /
• v.25 no.5
• /
• pp.319-322
• /
• 1998

Culture conditions for high frequency embryogenesis and plant regeneration in anther cultures of various F$_1$ hybrid and homozygous lines of pepper (Capsicum annuum L.) are described. Anthers pigmented less than halfway from the distal end were dissected from the flower bud in which petals elongated 2 mm higher than the receptacle. They were placed on Dumas medium supplemented with 0.1 mg/L 2,4-D and 0.1 mg/L kinetin. After four weeks of culture, embryos began to appear on anthers. After eight weeks of culture, frequencies of embryo formation reached up to 58.3%. Upon transfer to MS basal medium, greater than 95% of embryos developed into plantlets.

• Journal of Plant Biology
• /
• v.39 no.4
• /
• pp.243-247
• /
• 1996

Phosphoribosylanthranilate transferase (PAT) catalyzes the second step of the tryptophan biosynthetic pathway and is encoded by a single-copy gene that complements all the visible phenotypes of the tryptophan mutant (trp1-100) of Arabidopsis. The trp1-100 is blue fluorescent under UV light becuase it accumulates anthranilate. To obtain a plant with reduced PAT activity, PAT1 genes with several internal deletions in different promoter regions (pHS 101, pHS102, pHS104, pHS105, and pHS107) were induced into trp1-100 via Agrobacterium. Then, homozygous T3 plants were isolated and examined for blue fluorescence. Introduction of the PAT1 gene fusants results in the reversion of fluorescence phenotype except in the case of pHS105. These results prompted us to perform a parallel analysis of anthranilate synthase and PAT interms of the genetic complementation. A plant line carrying pHS105 gene fusant does not completely complement the blue fluorescence but it accumulates less anthranilate than trp1-100. The activity of PAT was reduced in the transgenic mutant as well. The plant carrying these constructs will add to the growing collection of molecular tools for the study of the indolic secondary metabolism.

• Research in Plant Disease
• /
• v.18 no.4
• /
• pp.304-309
• /
• 2012

Fusarium wilt, caused by three races of Fusarium oxysporum f. sp. lycopersici, is one of the most important disease of tomato (Solanum lycopersicum) worldwide. A total of 1,906 tomato accessions were screened for the resistance to Fusarium wilt using I-3 SNP marker and high resolution melting analysis. Results showed that 97 accessions were homozygous resistant, 8 accessions were heterozygous resistant and 1,801 were homozygous susceptible. Accessions containing resistance were identified in 65 accessions of S. lycopersicum var. lycopersicum, 13 accessions of S. lycopericum var. cerasiform, 8 accessions of S. pimpinellifolium, 3 accessions of S. habrochaites, 3 accessions of S. corneliomulleri, 1 accession of S. galapagense, 3 accessions of S. peruvianum, 1 accession of S. chilense. For accurate evaluation of the Fusarium wilt resistance, however, screening to race 1 and race 2 and bio-assay still remain to be evaluated.

• Journal of Life Science
• /
• v.31 no.2
• /
• pp.115-125
• /
• 2021

Calcium-dependent protein kinases (CDPKs) are known to be involved in regulating plant responses to abiotic stresses such as salinity, cold temperature and dehydration,. Although CDPKs constitute a large multigene family consisting of 31 genes in rice, only a few rice CDPKs' functions have been identified. Therefore, in order to elucidate the functions of OsCPK11 in rice, this study was intended to focus on the expression pattern analysis of OsCPK11 in wild type and ND0001 oscpk11 mutant plants under these abiotic stresses. For the salt, cold and drought stress treatment, seedlings were exposed to 200 mM NaCl, 4℃ and 20% PEG 6,000, respectively. RT-PCR and quantitative real-time PCR were performed to determine the expression patterns of OsCPK11 in wild type and ND0001 mutant plants. RT-PCR results showed that OsCPK11 transcripts in the wild type and heterozygous mutant were detected, but not in the homozygous mutant. Real-time PCR results showed that relative expression of OsCPK11 of wild type plants was increased and reached to the highest level at 24 hr, at 6 hr and at 24 hr under salt, cold and drought stress conditions, respectively. Relative expression of OsCPK11 of ND0001 homozygous plant was significantly reduced compared to that of wild type. These results suggested that oscpk11 homozygous mutant knocks out OsCPK11 and OsCPK11 might be involved in salt, cold and drought stress signaling by regulating its gene expression.

• Journal of Plant Biotechnology
• /
• v.42 no.1
• /
• pp.13-18
• /
• 2015

In this study we confirmed the stable integration of Arabidopsis AVP1 in the genomes of bottle gourd $T_3$ homozygous lines and its transcription, and additionally evaluated possibility of translocation of the AVP1 mRNA from transgenic bottle gourd rootstocks to wild type watermelon scions. Each AVP1 gene in two bottle gourd T3 lines is abundantly expressed under a field condition. Given the grafting between wild type watermelon scions and AVP1-expressing bottle gourd rootstocks, no translocation of the AVP1 mRNA was detected in leaves, both sexual flowers, and fruits of the scions.

• Proceedings of the Korean Society of Plant Biotechnology Conference
• /
• 2005.11a
• /
• pp.95-105
• /
• 2005

Transposon-mediated insertional mutagenesis provides one of the most powerful tools for functional studies of genes in higher plants. This project has been performed to develop a large population of insertional mutations, and to construct databases of molecular information on Ds insertion sites in rice. Ultimate goals are to supply genetic materials and information to analyze gene function and to identify and utilize agronomically important genes for breeding purpose. Two strategies have been employed to generate the large scale of transposon population in a Japonica type rice, Dongjin Byeo; 1) genetic crosses between Ac and Ds lines and 2) plant regeneration from seeds carrying Ac and Ds. Our study showed that over 70% of regenerated plants generally carried independent Ds elements and high activity of transposition was detected only during regeneration period. Ds-flanking DNA amplified from leaf tissues of F2 and T1 (or T2) plants have been amplified via TAIL-PCR and directly sequenced. So far, over 65,000 Ds lines have been generated and over 9,500 Ds loci have been mapped on chromosomes by sequence analysis. Database of molecular information on Ds insertion sites has been constructed, and has been opened to the public and will be updated soon at http://www.niab.go.kr. Detailed functional analysis of more than 30 rice mutants has been performed. Several Ds-tagged rice genes that have been selected for functional analysis will be briefly introduced. We expect that a great deal of information and genetic resources of Ds lines would be obtained during the course of this project, which will be shared with domestic and international rice researchers. In addition to the Japonica rice, we have established the tagging system in an rice line of indica genetic background, MGRI079. MGRI079 (Indica/Japonica) was transformed with Agrobacteria carrying Ac and Ds T-DNA vectors. Among transgenic lines, we successfully identified single-copy Ds and Ac lines in MGR1079. These lines were served as ‘starter lines’ to mutagenize Indica genetic background. To achieve rapid, large scale generation of Ds transposant lines, MGR1079 transformants carrying homozygous Ac were crossed with ones with homozygous Ds, and $F_2$seeds were used for plant regeneration. In this year, over 2,000 regeneration plants were grown in the field. We are able to evaluate the tagging efficiency in the Indica genetic background in the fall.

• Proceedings of the Korean Society of Plant Pathology Conference
• /
• 2003.10a
• /
• pp.148.2-149
• /
• 2003

Cucumber fruit mottle mosaic tobamovirus (CFMMV) causes severe mosaic symptoms with yellow mottling on leaves and fruits, and occasionally severe wilting of cucumber plants. No genetic source of resistance against this virus has been identified. The genes coding for the coat protein or the putative 54-kDa replicase were cloned into binary vectors under control of the SVBV promoter. Agrobacterium-mediated transformation was peformed on cotyledon explants of a parthenocarpic cucumber cultivar with superior competence for transformation. R1 seedlings were evaluated for resistance to CFMMV infection by lack of symptom expression, back inoculation on an alternative host and ELISA. From a total of 14 replicase-containing R1 lines, 8 exhibited immunity, while only 3 resistant lines were found among a total of 9 CP-containing lines. Line 144 homozygous for the 54-kDa replicase was selected for further resistance analysis. Line 144 was immune to CFMMV infection by mechanical and graft inoculation, or by root infection following planting in CFMMV-contaminated soil. Additionally, line 144 showed delay of symptom appearance following infection by other cucurbit-infecting tobamoviruses. Infection of line 144 plants with various potyviruses and cucumber mosaic cucumovirus did not break the resistance to CFMMV. The mechanism of resistance of line 144 appears to be RNA-mediated, however the means is apparently different from the gene silencing phenomenon. Homozygote line 144 cucumber as rootstock demonstrated for the first time protection of a non-transformed scion from soil inoculation with a soil borne pathogen, CFMMV.

• Proceedings of the Korean Society of Crop Science Conference
• /
• 2017.06a
• /
• pp.107-107
• /
• 2017

Sweet corns are enjoyed worldwide as processed products and fresh ears. Types of sweet corn are based on the gene(s) involved. The oldest sweet corn type has a gene called "sugary (su)". Sugary-based sweet corn was typically named "sweet corn". With its relatively short shelf life and the discovery of a complementary gene, "sugary enhanced (se)", the sweet corn (su only) was rapidly replaced with another type of sweet corns, sugary enhanced sweet corn, which has recessive homozygous su/su, se/se genotype. With the incorporation of se/se genotype into existing su/su genotype, sugary enhanced sweet corn has better shelf life and increased sweetness while maintaining its creamy texture due to high level of water soluble polysaccharide, phytoglycogen. Super sweet corn as the name implies has higher level of sweetness and better shelf life than sugary enhanced sweet corn due to "shrunken2 (sh2)" gene although there's no creamy texture of su-based sweet corns. Distinction between sh2/sh2 and su/su genotypes in seeds is phenotypically possible. The Involvement of se/se genotype under su/su genotype, however, is visually impossible. The genotype sh2/sh2 is also phenotypically epistatic to su/su genotype when both genotypes are present in an individual, meaning the seed shape for double recessive sh2/sh2 su/su genotype is much the same as sh2/sh2 +/+ genotype. Hence, identifying the double and triple recessive homozygous genotypes from su, se and sh2 genes involves a testcross to single recessive genotype, chemical analysis or DNA-based marker development. For these reasons, sweetcorn breeders were hastened to put them together into one cultivar. This, however, appears to be no longer the case. Sweet corn companies began to sell their sweet corn hybrids with different combinations of abovementioned three genes under a few different trademarks or genetic codes, i.g. Sweet $Breed^{TM}$, Sweet $Gene^{TM}$, Synergistic corn, Augmented Supersweet corn. A total of 49 commercial sweet corn F1 hybrids with B73 as a check were genotyped using DNA-based markers. The genotype of field corn inbred B73 was +/+ +/+ +/+ for su, se and sh2 as expected. All twelve sugary enhanced sweet corn hybrids had the genotype of su/su se/se +/+. Of sixteen synergistic hybrids, thirteen cultivars had su/su se/se sh2/+ genotype while the genotype of two hybrids and the remaining one hybrid was su/su se/+ sh2/+, and su/su +/+ sh2/+, respectively. The synergistic hybrids all were recessive homozygous for su gene and heterozygous for sh2 gene. Among the fifteen augmented supersweet hybrids, only one hybrid was triple recessive homozygous (su/su se/se sh2/sh2). All the other hybrids had su/su se/+ sh2/sh2 for one hybrid, su/su +/+ sh2/sh2 for three hybrids, su/+ se/se sh2/sh2 for three hybrids, su/+ se/+ sh2/sh2 for four hybrids, and su/+ +/+ sh2/sh2 for three hybrids, respectively. What was believed to be a classic super sweet corn hybrids also had various genotypic combination. There were only two hybrids that turned out to be single recessive sh2 homozygous (+/+ +/+ sh2/sh2) while all the other five hybrids could be classified as one of augmented supersweet genotypes. Implication of the results for extension service and sweet corn breeding will be discussed.

• Genomics & Informatics
• /
• v.19 no.2
• /
• pp.19.1-19.9
• /
• 2021

Plant height is an important component of plant architecture and significantly affects crop breeding practices and yield. We studied DNA variations derived from F5 recombinant inbred lines (RILs) with 96.8% homozygous genotypes. Here, we report DNA variations between the normal and dwarf members of four lines harvested from a single seed parent in an F6 RIL population derived from a cross between Glycine max var. Peking and Glycine soja IT182936. Whole genome sequencing was carried out, and the DNA variations in the whole genome were compared between the normal and dwarf samples. We found a large number of DNA variations in both the dwarf and semi-dwarf lines, with one single nucleotide polymorphism (SNP) per at least 3.68 kb in the dwarf lines and 1 SNP per 11.13 kb of the whole genome. This value is 2.18 times higher than the expected DNA variation in the F6 population. A total of 186 SNPs and 241 SNPs were discovered in the coding regions of the dwarf lines 1282 and 1303, respectively, and we discovered 33 homogeneous nonsynonymous SNPs that occurred at the same loci in each set of dwarf and normal soybean. Of them, five SNPs were in the same positions between lines 1282 and 1303. Our results provide important information for improving our understanding of the genetics of soybean plant height and crop breeding. These polymorphisms could be useful genetic resources for plant breeders, geneticists, and biologists for future molecular biology and breeding projects.

• BMB Reports
• /
• v.43 no.5
• /
• pp.330-336
• /
• 2010

5-Aminolevulinate (ALA) is well-known as an essential biosynthetic precursor of all tetrapyrrole compounds, which has been suggested to improve plant salt tolerance by exogenous application. In this work, the gene encoding aminolevulinate synthase (ALA-S) in yeast (Saccharomyces cerevisiae Hem1) was introduced into the genome of Arabidopsis controlled by the Arabidopsis thaliana HemA1 gene promoter. All transgenic lines were able to transcribe the YHem1 gene, especially under light condition. The chimeric protein (YHem1-EGFP) was found co-localizing with the mitochondria in onion epidermal cells. The transgenic Arabidopsis plants could synthesize more endogenous ALA with higher levels of metabolites including chlorophyll and heme. When the $T_2$ homozygous seeds were cultured under NaCl stress, their germination and seedling growth were much better than the wild type. Therefore, introduction of ALA-S gene led to higher level of ALA metabolism with more salt tolerance in higher plants.