• Journal of Applied Biological Chemistry
• /
• v.49 no.3
• /
• pp.75-81
• /
• 2006

A full-length cDNA encoding dihydroflavonol 4-reductase (st-dfr) of potato was isolated by rapid amplification of cDNA ends, and their expression was investigated from purple-fleshed potato (Solanum tuberosum L. cv. Jashim). The st-dfr exists as a member of a small gene family and its transcripts was abundant in the order of tuber flesh, stem, leaf, and root. The expressions of st-dfr gene were light inducible and cultivar dependant. Transgenic potato plants harboring antisense st-dfr (AS-DFR) sequences were analyzed. The accumulation of mRNA was nearly completely inhibited as a result of introducing an AS-DFR gene under the control of the 35S CaMV promoter into the red tuber skin Solanum tuberosum L. cv. Desiree. The anthocyanin content of the tuber peels of the transgenic lines was dramatically decreased by up to 70%. The possible production of flavonols in the peels of AS-DFR transgenic potatoes was discussed.

• Korean Journal of Food Science and Technology
• /
• v.22 no.7
• /
• pp.753-761
• /
• 1990

The physicochemical properties of starches from aerial and subterranean tuber of yam were compared with those of rice and sweet potato. Aerial tuber yam contained higher level of amylose than others, whereas water binding capacity, swelling power and solubility was highest in subterranean tuber yam starch. Brabender amylograms of 5% starch suspensions indicated that the initial pasting temperature of yam starches were slightly higher than that of rice and sweet potato starches, the maximum viscosities of starches from subterranean and aerial tuber yam were 860 and 590 B.U., respectively. Yam starches were more difficult to hydrolyze by ${\alpha}-amylase$ than rice and sweet potato starches. ${\beta}-Amylolysis\;limit$ for yam starches and their amylose and amylopectin were higher than rice and sweet potato starches. The elution profiles of starches on Sepharose CL-2B were different from each other but they were similar between yam starches. Incomplete debranched fractions in the aerial tuber yam amylopectin was particularly higher than other samples. The weight ratio of short chains to long chains for debranched amylopectins was the lowest in aerial tuber yam.

• KOREAN JOURNAL OF CROP SCIENCE
• /
• v.46 no.1
• /
• pp.1-5
• /
• 2001

Field experiment was conducted during 1993-94 season to determine the pattern of nutrient uptake and productivity of maize/sweet potato intercropping system. Four levels of nitrogen (0, 50, 100 and 150kg N ${ha}_{-1}$) and four levels of potassium (0, 40, 80 and 120kg $K_2$O ${ha}_{-1}$) formed treatment variables. Plants were sampled periodically to determine dry matter and tissue concentrations of N and K in the individual plant components of intercropped maize and sweet potato. Nitrogen and potassium fertilizer did not interact significantly to nutrient uptake by any plant parts of intercropped maize and sweet potato. But application of N fertilizer independently enhanced N uptake in all the plant parts of maize and sweet potato. The uptake of N in leaf, leaf sheath, stem, husk, and cob of maize increased upto 90 days after planting (DAP) but grain continued to accumulate N till its maturity. Sweet potato exhibited a wide variation in N uptake pattern. Sweet potato leaf shared the maximum uptake of N at 50 DAP which rapidly increased at 70 DAP and then declined. Declination of N uptake by petiole and stem were observed after 120 DAP whereas N uptake by tuber increased slowly upto 90 DAP and then rapidly till harvest. Rate of applied K had very little effect on the uptake patterns in different components of intercropped maize. Pattern of K uptake by leaf, petiole and stem of sweet potato showed almost similar trend to N uptake. But uptake of K by tuber increased almost linearly with the K application. Pattern of N and K uptake by grain and tuber paralleled the grain yield of maize and sweet potato respectively. Intercropped productivity of maize and sweet potato found to be better by the application of 100kg N and 120 kg $K_2$O ${ha}_{-1}$

• The Korean Journal of Food And Nutrition
• /
• v.12 no.5
• /
• pp.478-483
• /
• 1999

This study was conducted to investigate functional properties of 70% acetone extract in different parts of two potato varieties. 'Superior' and 'Atlantic' potato were processed by following method. Potatoes are washed, peeled, sliced and steamed before hot air drying for flesh and peel powder. Hunter's L and b values of flesh powder from blanched 'Superior' potato were higher than flesh powder from fresh 'Superior' potato. Discoloration of 'Superior' potato was inhibited by steam blanching. Contents of total polyphenol and chlorogenic acid in the 70% acetone extract of 'Superior' potato were higher than those of 'Atlantic' potato paticularly in the blanched flesh and peel. But flavonoid was not detected in flesh extract. The phenolic concentration was not decreased by the heat treatment. The nitritescavenging and electron donating ability was greatest at the tuber peel including the skin and cortex tissue 1mm beneath the skin. From the above results browning reaction and polyphenol contents in different parts of potato slices were dependent on cutivars. Peels contained more polyphenols than those from the flesh. The results indicate that potato peel extract of steam blanched plus hot air dried potato tuber showed the effectiveness as a natural nitrite scavenger and antioxidant.

• BMB Reports
• /
• v.29 no.2
• /
• pp.163-168
• /
• 1996

Glycosylated polyphenol oxidase was purified from potato tuber using ammonium sulfate fractionation, Sephadex G-100, and concanavalin A Sepharose column chromatography. Two or three types of polyphenol oxidase were separated on concanavalin A Sepharose. Type I and II polyphenol oxidases did not bind to concanavalin A Sepharose. Type I seemed to be an aggregated form of polyphenol oxidase. Type III polyphenol oxidase, which is presumed to be glycosylated because it was bound to concanavalin A Sepharose and eluted with $\alpha$-D-methyl glucopyranoside, was further purified by chromatography on Econo-Pac Q and Superose 12. Glycosylated polyphenol oxidase was purified 130-fold from the dissolved ammonium sulfate pellet resulting in about $6\;{\mu}g$ of the enzyme from 100 g of potato tuber periderm. The molecular weight of the glycosylated enzyme determined by SDS-polyacrylamide gel electrophoresis was about 64,000. Optimum temperature and pH of both II and type III potato polyphenol oxidases were $20^{\circ}C$ and pH 7.0, respectively. Glycosylated form of polyphenol oxidase (type III) preferred catechol to catechin as a substrate, whereas type II enzyme showed the reverse substrate preference.

• Plant Biotechnology Reports
• /
• v.5 no.1
• /
• pp.27-34
• /
• 2011

Jasmonates control diverse plant developmental processes, such as seed germination, flower, fruit and seed development, senescence and tuberization in potato. To understand the role of methyl jasmonate (MeJA) in potato tuberization, the Arabidopsis JMT gene encoding jasmonic acid carboxyl methyltransferase was constitutively overexpressed in transgenic potato plants. Increases in tuber yield and size as well as in vitro tuberization frequency were observed in transgenic plants. These were correlated with JMT mRNA level-- the higher expression level, the higher the tuber yield and size. The levels of jasmonic acid (JA), MeJA and tuberonic acid (TA) were also higher than those in control plants. Transgenic plants also exhibited higher expression of jasmonate-responsive genes such as those for allene oxide cyclase (AOC) and proteinase inhibitor II (PINII). These results indicate that JMT overexpression induces jasmonate biosynthesis genes and thus JA and TA pools in transgenic potatoes. This results in enhanced tuber yield and size in transgenic potato plants.

• Journal of Plant Biotechnology
• /
• v.37 no.4
• /
• pp.388-393
• /
• 2010

Recently, a number of successful research reports are accumulated to increase the carotenoid level in potato tuber such as $\beta$-carotene, precursor of vitamin A and keto-carotenoid like astaxanthin in which is not synthesized in most plants tissue since it does not contain a specific enzyme to add keto-ring in carotenoid molecule. In particular, keto-carotenoids are more interested due to their strong antioxidant activity. Currently, the content of $\beta$-carotene was increased up to 3,600-fold ($47\;{\mu}g/g$ dry weight) when compared to the control potato tuber, parental cultivar for genetic modification. In addition, astaxanthin, one of the major keto-carotenoid was accumulated up to $14\;{\mu}g/g$ dry weight in potato tuber with red color by over expressing the gene encoding $\beta$-carotene ketolase isolated from marine microorganisms. In this article, we summarized carotenogenesis-related genes that have been used for metabolic engineering of carotenoid biosynthetic pathway in potato. Furthermore, strategies for the accumulation of carotenoids and ketocarotenoids in specific potato tuber, bottle necks, and future works are discussed.

• Animal Systematics, Evolution and Diversity
• /
• v.29 no.1
• /
• pp.70-73
• /
• 2013

Diadegma fenestrale is known as a parasitoid of the potato tuber moth, Phthorimaea operculella. The potato tuber moth, Phthorimaea operculella (Zeller) is one of the most destructive pest of potatoes. Also, we found this species attacking the diamondback moth, Plutella xylostella (Lepidoptera: Plutellidae). Ratio of parasitism is 20-30% and cocoon of lepidopteran was parasitic ichneumonid species after 3 days. This species and the genus Diadegma are recorded for the first time from Korea. In this paper, description of the parasitoid and photographs of the diagnostic characteristics are provided.

• Proceedings of the Korean Society of Crop Science Conference
• /
• 2018.10a
• /
• pp.179-179
• /
• 2018

Potato (Solanum tubersosum L.) is susceptible to various environmental stresses such as salt, high temperature, and drought. Especially, potato tuber growth is greatly affected by drought that causes not only yield reduction but also loss of tuber quality. Since unpredictable global weather changes cause more severe and frequent water limiting conditions, improvement of potato drought tolerance can minimize such adverse effects under drought and can impact on sustainable potato production. Genetic engineering can be utilized to improve potato drought tolerance, but such approaches using endogenous potato genes have rarely been applied. We were obtained AtbZIP28 gene transgenic potato plants. It is identified transcript levels at various stress conditions, polyethylene glycol (PEG), NaCl, (ABA). Also, For identification to regulate ER stress response genes in AtbZIP28 gene transgenic potato plant, we screened seven potato genes from RNA-seq analysis under TM treatment. Five and two genes were up- and down-regulated by TM, respectively. Their expression patterns were re-examined at stress agents known to elicit TM, DTT, DMSO and salt stress.

• KOREAN JOURNAL OF CROP SCIENCE
• /
• v.48 no.3
• /
• pp.147-151
• /
• 2003

Normal seed tubers and plug seedlings raised from stem cutting and mini-tubers ($10\pm3$ g) were planted or transplanted on August 20,2001 in bare soil or under transparent and black polyethylene film mulches to evaluate the effects of mulch material and seedling type on the growth and tuber yield of fall-grown potato (Solanum tuberosum L. cv. Dejima) in Jeju region. Total tuber number per plant was 4.6 regardless of mulch treatment, and direct planting seed potatoes resulted in the greatest tubers (5.14)/plant and followed by transplanting seedlings raised from cutting and mini-tubers (4.15 and 5.15 tubers/plant). Transparent and black polyethylene film mulches increased total tuber yield by 16 and 8%, respectively, and average tuber weight by 14 and 12%, respectively, compared with no mulch (21.16 t/ha and 72.2 g/tuber). Transplanting plug seedlings raised from cutting resulted in the greatest tuber yield, followed by transplanting plug seedlings raised from mini-tubers and direct planting seed potatoes.