• Journal of Plant Biotechnology
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• v.48 no.4
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• pp.223-227
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• 2021

Several hypotheses for the origin of cultivated sweetpotato [Ipomoea batatas L. (Lam)] have been suggested but the exact progenitor is still unknown. Based on the results of RFLP patterns, microsatellite markers, SNP markers, FISH analyses, and genome analyses of haplotypes, wild species belonging to batatas group, I. trifida, I. leucantha, I. littoralis, I. tabascana, I. tenuissima, I. tiliacea, and I. triloba have been suggested as a progenitor. However, recently, advanced genomic technologies and characterization of the inserted T-DNA fragments of Agrobacterium in the genome of cultivated sweetpotato and wild species through horizontal gene transfer suggest that there may be an older progenitor than the wild species suggested so far.

• Journal of Plant Biotechnology
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• v.49 no.1
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• pp.39-45
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• 2022

Conserved domains are defined as recurring units in molecular evolution and are commonly used to interpret the molecular function and biochemical structure of proteins. Herein, the ADP-glucose pyrophosphorylase (AGPase) amino acid sequences of three species of the Ipomoea genus [Ipomoea trifida, I. triloba, and I. batatas (L.) Lam. (sweetpotato)] were identified to investigate their physicochemical and biochemical characteristics. The molecular weight, isoelectric point, instability index, and grand average of hyropathy markedly differed among the three species. The aliphatic index values of sweetpotato AGPase proteins were higher in the small subunit than in the large subunit. The AGPase proteins from sweetpotato were found to contain an LbH_G1P_AT_C domain in the C-terminal region and various domains (NTP_transferase, ADP_Glucose_PP, or Glyco_tranf_GTA) in the N-terminal region. Conversely, most of its two relatives (I. trifida and I. triloba) were found to only contain the NTP_transferase domain in the N-terminal region. These findings suggested that these conserved domains were species-specific and related to the subunit types of AGPase proteins. The study may enable research on the AGPase-related specific characteristics of sweetpotatoes that do not exist in the other two species, such as starch metabolism and tuberization mechanism.

• Journal of Plant Biotechnology
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• v.32 no.4
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• pp.263-268
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• 2005

Porcine epidemic diarrhea virus (PEDV) causes acute enteritis in pigs of all ages and is often fatal for neonates. In order to develop sweetpotato plants expressing PEDV antigen, we constructed the vector expressing spike gene of PEDV under the control of sweetpotato sporamin promoter or constitutive CaMV 35S promoter. The spike protein region of PEDV was synthesized by PCR and linked to each promoter, Transgenic sweetpotato [Ipomoea batatas (L.) Lam. cv. Yulmi] plants were developed from embryogenic calli following Agrobacterium tumefaciens-mediated transformation. The co-cultured embryogenic calli transferred to selective MS medium containing 1 mg/L 2,4-D, 100 mg/L kanamycin, and 400 mg/L claforan. These embryogenic calli were subcultured to the same selection medium at 3 weeks interval. Kanamycin-resistant calli transferred to hormone-free MS medium with kanamycin gave rise to somatic embryos and then converted into plantlets in the same medium. Southern blot analysis confirmed that the spike gene of PEDV was inserted into the genome of the sweetpotato plants. RT-PCR revealed that the spike gene of PEDV was highly expressed in transgenic sweetpotato plants.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.47
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• pp.124-134
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• 2002

The sweetpotato, Ipomoea batatas L. (Lam.), is one of the important summer upland crops in Korea and has been used as human food, industrial yaw material and vegetable. Sweetpotato has been consumed for human foods such as boiled, roasted, fried or salad etc. It should be developed for higher quality as a snack or health food, primarily through improving the eating and marketing qualities as well as nutritional value. Its quality after cooking or processing is a complex one combining the aroma, taste, texture and fiber content. The other important qualities for consumers are root shape, size, skin color, flesh color, insect and disease resistance, nutritional components and safety from phytoalexins(toxic stress metabolites) etc. Korean people generally prefer to red skin color, round or elliptic shape and dry texture, yellow flesh color of sweetpotato which is high in starch content including vitamins and nutrients. The almost factors of quality components of sweetpotato are genetically controlled by breeder, but postharvest handlings and marketing management for making high quality goods should be done thoroughly according to the quality evaluation criteria of sweetpotato from the moment of harvest until shipping them to the market by farmers and the other users. This paper describes current status and prospects of the quality evaluations and researches in sweetpotato roots in Korea.

• Journal of Plant Biotechnology
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• v.31 no.4
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• pp.267-271
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• 2004

Transformed sweetpotato (Ipomoea batatas (L.) Lam. cv. Yulmi) plants were developed from embryogenic calli following Agrobacterium tumefaciens-mediated transformation. A. tumefaciens strain EHA105/pCAMBIA2301 harboring genes for intron $\beta$-glucuronidase (GUS) and kanamycin resistance. Transient expression of GUS gene was found to be higher when embryogenic calli were co-cultivated with Agrobacterium for 2 days. The co-cultured embryogenic calli transferred to selective MS medium containing 1mg/L 2,4-D, 100mg/L kanamycin, and 400mg/L claforan. These embryogenic calli were subcultured to the same selection medium at 4 weeks interval. Kanamycin-resistant calli transferred to hormone-free MS medium with kanamycin gave rise to somatic embryos and then converted into plantlets in the same medium. Southern blot analysis confirmed that the GUS gene was inserted into the genome of the sweetpotato plants. A histochemical assay revealed that the GUS gene was preferentially expressed in the leaf, petiole, and vascular tissue and tip of root.

• Proceedings of the Korean Society of Crop Science Conference
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• 2001.09a
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• pp.182-183
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• 2001

• The Korean Journal of Food And Nutrition
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• v.28 no.4
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• pp.571-578
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• 2015

This study was carried out to investigate the quality characteristics of bread containing sweetpotato (Ipomoea batatas (L.) Lam) leaf powder (0, 2, 3, 5, and 7% of the total flour). We found that the addition of sweetpotato leaf powder decreased the pH of the dough, whereas the total titratable acidity increased and the specific volume and baking loss of bread were decreased. However, the moisture content of the bread did not show any significant differences. The L and a values of the bread inner crumb were decreased by the addition of sweetpotato leaf powder, however, the b value was increased. The 2,2-diphenyl-1-picrylhydrazyl-radical scavenging activity, total polyphenol, lutein and ${\beta}-carotene$ contents were increased significantly by the addition of sweetpotato leaf powder. The taste, color, flavor, chewiness and overall acceptability of bread containing 2~3% sweetpotato leaf powder were better than those of the controls. We found that the sample group with 2~3% sweetpotato leaf powder is the optimum content for making bread.

• Journal of Plant Biotechnology
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• v.7 no.2
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• pp.123-127
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• 2005

The evaluation of source potential and sink strength is the generally large and laborious sample size required to adequately assess anyone of the parameters in field-grown sweetpotato. For this purpose we used the rooted single-leaf cuttings with petioles, because the source and sink organs are restricted in this system. The rooted single-leaf cutting of sweetpotato provides a unique source-sink model system, and is established within about 50 days after planting. In this study, the sink potential of sweetpotato tubers was examined based on the expression of genes for starch synthesis (AGPase) and modification (SBEII and GBSSI) in single rooted leaf plant. The gene expression patterns of GBSSI, SBEII and AGPase at various developmental stages and in different types of root tissues presented. These results suggest that the rooted single-rooted method can be used an ideal model system to study physiological and biochemical mechanisms in sweetpotato.

• Proceedings of the Korean Society of Plant Biotechnology Conference
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• 2005.11a
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• pp.351-355
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• 2005

In the storage roots of sweetpotato (Ipomoea batatas (L.) Lam. cv. Kokei 14), 10 to 20% of starch is essentially unbranched linear amylose and the other major component is branched amylopectin. Amylose is produced by the enzyme GBSSI (granule bound starch synthase I), whereas amylopectin is produced by a concerted action of soluble starch synthase and starch branching enzymes (SBEI and SBEII). We constructed double-stranded RNA (dsRNA) interference vectors of GBSSI and IbSBEII and introduced them into sweetpotato genome via Agrobacterium-mediated gene transformation. The endogenous GBSSI expression was inhibited by dsRNA of GBSSI in 73 % of transgenic plants giving rise to the storage tubers containing amylopectin but not amylose. On the other hand, all sweetpotato plants transformed with dsRNA of IbSBEII contained a larger amount of amylose than the non-transgenic control (up to 25% compared to 10% in the controls). The RNA interference (RNAi) is effectively inhibited the gene expression in thestarch metabolic pathway and modified the characteristics of starch in sweetpotato.

• BMB Reports
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• v.42 no.5
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• pp.271-276
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• 2009

Sweetpotato (Ipomoea batatas (L). Lam.) is relatively tolerant to unfavorable growth conditions such as drought, yet has not been exploited to provide a better understanding of the molecular basis of drought stress tolerance. We obtained 983 high-quality expressed sequence tags of 100 bp or longer (average length of 700 bp) from cDNA libraries of detached white fibrous root tissues by subjecting them to dehydration for 6 h. The 431 cDNAs were each assigned a function by alignment using the BLASTX algorithm. Among them, three genes associated with various abiotic stresses and nine genes not previously associated with drought stress were selected for expression pattern analysis through detailed reverse transcription-polymerase chain reaction. The direct and indirect relationships of the 12 genes with drought tolerance mechanisms were ascertained at different developmental stages and under various stress conditions.