• The Plant Pathology Journal
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• v.38 no.3
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• pp.220-228
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• 2022

Pollen is a vector for viral transmission. Pollenmediated viruses cause serious economic losses in the fruit industry. Despite the commercial importance of pollen-associated viruses, the diversity of such viruses is yet to be fully explored. In this study, we performed metatranscriptomic analyses using RNA sequencing to investigate the viral diversity in imported apple and kiwifruit pollen. We identified 665 virus-associated contigs, which corresponded to four different virus species. We identified one virus, the apple stem grooving virus, from pear pollen and three viruses, including citrus leaf blotch virus, cucumber mosaic virus, and lychnis mottle virus in kiwifruit pollen. The assembled viral genome sequences were analyzed to determine phylogenetic relationships. These findings will expand our knowledge of the virosphere in fruit pollen and lead to appropriate management of international pollen trade. However, the pathogenic mechanisms of pollen-associated viruses in fruit trees should be further investigated.

• Journal of Life Science
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• v.34 no.7
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• pp.493-499
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• 2024

Antimicrobial peptides are antimicrobial substances inherent in animals and plants, with strong antibacterial activity even in small amounts and with various other functions such as antiviral and antioxidant actions. Plants can be grown with just water and sunlight, allowing for their mass production at low costs. However, transforming a chloroplast into one that produces antimicrobial peptides, rather than growing plants, increases the amount of protein expression and minimizes contamination of the ecosystem because gene transfer by pollen does not occur. In that context, using transgenic plant chloroplasts to produce recombinant proteins increases protein degradation and reduces the solubility of proteins. To solve this problem, we fused SUMO, a fusion protein, with a recombinant protein. We also used a 6xHis tag to purify the fusion protein. The antimicrobial peptide stomoxyn is an antibacterial substance found in stable flies. Stomoxyn has an α-helix structure and is amphiphilic, which allows it to dissolve bacterial cell membranes. In this study, we constructed a transformation vector to express stomoxyn in both plant chloroplasts and Escherichia coli and used this vector to confirm the expression of stomoxyn in E. coli. The expression of the protein was then confirmed in E. coli using a transformation vector. The expressed stomoxyn was purified by nickel column and SUMOase treatment, and its antibacterial activity was confirmed using an agar diffusion assay. The EGFP gene was used to ensure that the transformed vector was inserted into the chloroplast.

• Journal of Ecology and Environment
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• v.29 no.4
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• pp.353-360
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• 2006

Ecological correlates of flowering times often are examined to infer evolutionary mechanisms for flowering time diversities. We examined ecological characteristic associations such as growth habits and pollination modes with flowering times among 3,037 Korean angiosperms experiencing strong climatic seasonalities. We first examined taxonomic membership effects on flowering times across diverse taxonomic levels. Phylogeny constrained flowering times at all levels down to the genus level. We then analyzed the effects of ecological characteristics using subset data consisting of species randomly selected from each genus to control phylogenetic effects. The commonly observed patterns of early flowering of woody species in temperate regions existed. Spring flowering shrubs and trees, however, both being woody, were involved with biotic and abiotic vectors, respectively. In two herbaceous groups of annuals and perennials, annuals flowered later in the growing season than perennials although both herbs tended to be associated with abiotic vectors when flowering in autumn. These results support our hypothesis that species able to decouple vegetative and reproductive growth flower in spring's dry season, but species with different habits, even when they flower within the same season, are subjected to different selective pressures for efficient pollination.

• Korean Journal of Plant Taxonomy
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• v.38 no.1
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• pp.43-50
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• 2008

The pollination system of Bupleurum latissimum Nakai (Apiaceae) was investigated in the natural population of Korea. The various insects of 19 species, 11 families, 5 orders visited the flowers of B. latissimum. Episyrphus balteatus and Lasioglossum occidens were considered as the most effective pollen vector which have associated specially with B. latissimum. The visitation frequency peaked at 10 AM - 13 PM and no visitor was recognized during night time. The flowers of B. latissimum last during only three days and they are protandry. It is also confirmed that the flower of B. latissimum is self-compatible and cross-pollination by vectors is critical for successful seed setting.

• Journal of Plant Biotechnology
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• v.38 no.1
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• pp.42-48
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• 2011

Chloroplast genetic engineering of higher plants offers several unique advantages compared with nuclear genome transformation, such as high levels of transgene expression, a lack of position effect due to site-specific transgene integration by homologous recombination, multigene engineering in a single transformation event and reducing risks of gene flow via pollen due to maternal inheritance. We established a reproducible chloroplast transformation system of potato using a tobacco specific plastid transformation vector, pCtVG (trnI-Prrn-aadA-mgfp-TpsbA-trnA). Stable transgene integration into chloroplast genomes and the homoplasmic state of the transgenome were confirmed by PCR and Southern blot analyses. Northern, immunoblot analysis, and GFP fluorescence imaging revealed high expression and accumulation of GFP in the plastids of potato leaves. This system would provide new opportunities for genetic improvement and mass production of value added foreign proteins in this crop.