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PubMed1995

Composition of sulfited potatoes: comparison with fresh and frozen potatoes.

The content in moisture, fat, protein, carbohydrate, fibre and vitamin C was analyzed in three commercial types of potatoes: sulfited (treated with E223), frozen potatoes (pre-fried) and fresh potatoes (not processed). The composition of sulfited potatoes does not usually appear in food composition tables. Our results showed significant differences in the content of carbohydrates and fibre between sulfited and fresh potatoes. The content of vitamin C in sulfited potatoes, which is similar to that of frozen potatoes, was shown to be approximately half of that found in fresh potatoes.

Ascorbic Acid↗
PubMed2003

Construction of two BAC libraries from the wild Mexican diploid potato, Solanum pinnatisectum, and the identification of clones near the late blight and Colorado potato beetle resistance loci.

To facilitate isolation and characterization of disease and insect resistance genes important to potato, two bacterial artificial chromosome (BAC) libraries were constructed from genomic DNA of the Mexican wild diploid species, Solanum pinnatisectum, which carries high levels of resistance to the most important potato pathogen and pest, the late blight and the Colorado potato beetle (CPB). One of the libraries was constructed from the DNA, partially digested with BamHI, and it consists of 40328 clones with an average insert size of 125 kb. The other library was constructed from the DNA partially digested with EcoRI, and it consists of 17280 clones with an average insert size of 135 kb. The two libraries, together, represent approximately six equivalents of the wild potato haploid genome. Both libraries were evaluated for contamination with organellar DNA sequences and were shown to have a very low percentage (0.65-0.91%) of clones derived from the chloroplast genome. High-density filters, prepared from the two libraries, were screened with ten restriction fragment length polymorphism (RFLP) markers linked to the resistance genes for late blight, CPB, Verticillium wilt and potato cyst nematodes, and the gene Sr1 for the self-incompatibility S-locus. Thirty nine positive clones were identified and at least two positive BAC clones were detected for each RFLP marker. Four markers that are linked to the late blight resistance gene Rpi1 hybridized to 14 BAC clones. Fifteen BAC clones were shown to harbor the PPO (polyphenol oxidase) locus for the CPB resistance by three RFLP probes. Two RFLP markers detected five BAC clones that were linked to the Sr1 gene for self-incompatibility. These results agree with the library's predicted extent of coverage of the potato genome, and indicated that the libraries are useful resources for the molecular isolation of disease and insect resistance genes, as well as other economically important genes in the wild potato species. The development of the two potato BAC libraries provides a starting point, and landmarks for BAC contig construction and chromosome walking towards the map-based cloning of agronomically important target genes in the species.

Animals↗
PubMed1993

Speciation of plutonium in potato and the gastrointestinal transfer of plutonium and americium from potato.

Complexation of Pu(IV) and Am(III) by naturally occurring agents such as citrate and phytate might enhance their uptake from the digestive tract. However, the extent to which they enhance the gastrointestinal uptake of actinides from foodstuffs is far from resolved, as this study shows. Investigations of the chemical forms of Pu(IV) and Am(III), by gel permeation chromatography, in simulated digests of potato tubers naturally radiolabelled with 239Pu(IV) and 241Am(III) have shown that neither citrate nor phytate appear to determine their chemical forms. Therefore, it is possible that these are not the complexing anions which determine the gastrointestinal transfer of these radioelements from potato meal. Isotachophoretic analyses of the juices pressed from tubers and solutions prepared by simulated digestion of potato tubers have demonstrated the presence of several low molecular weight anions. These anions might be complexing agents because they possess an isotachophoretic mobility similar to that of citrate; some of these anions remain unidentified. Whereas 239Pu and 241Am were used in the foregoing studies, 238Pu and 241Am were used to produce either in vitro or naturally radiolabelled potatoes for gastrointestinal transfer measurements using rats and hamsters. Gastrointestinal transfer values of 0.13 +/- 0.05% (mean +/- standard error of mean) and 0.16 +/- 0.06% were determined with rats for the uptake of 238Pu and 241Am, respectively, from naturally labelled potato meal. Higher gastrointestinal transfer values were obtained for hamsters: for 238Pu and 241Am the transfer values from naturally labelled meal were 0.25 +/- 0.08% and 0.33 +/- 0.07%, respectively. Similar values were observed for uptake from in vitro labelled potato meal. On the basis of the similarity of the values for the naturally labelled potato meal and for the 'spiked' potato meal it would appear that biological incorporation is not necessary for the binding of the actinides to the ligands which will determine gastrointestinal transfer.

Americium↗
PubMed2001

Physiological response of Colorado potato beetle and beet armyworm larvae to depletion of wound-inducible proteinase inhibitors in transgenic potato plants.

Larvae of Colorado potato beetle (CPB), Leptinotarsa decemlineata, and beet armyworm (BAW), Spodoptera exigua, reared on potato plants in which wound-induced accumulation of proteinase inhibitors (PIs) was largely reduced through antisense-mediated depletion of a specific lipoxygenase (LOX H3) had significantly larger weight gains than those fed on non-transformed plants. The midgut endoproteolytic activities of CPB larvae fed on non-transformed potato were significantly higher than those from larvae fed on LOX-H3-deficient plants. However, none of these proteolytic activities was inhibited by potato leaf extracts, regardless of the plant that they were fed on. Taken together, these data suggest that CPB, a leaf-feeding specialist of solanaceous plants, is largely adapted to the inducible PIs of potato, though the metabolic cost associated with the hyperproduction of digestive proteases may account for the 14-31% lower weight gain of larvae fed on non-transformed plants. The effect of LOX-H3 depletion on insect performance was more evident with larvae of the polyphagous BAW (52-63% higher weight gain and 73% higher fecundity when reared on LOX-H3-deficient plants). The poorer larval performance of BAW on non-transformed plants may be due to the susceptibility to inhibition by potato leaf tissues of most BAW digestive proteases. Indeed, BAW larvae fed on non-transformed potato showed a significant reduction in most endoproteolytic activities compared to larvae fed on LOX-H3-deficient plants, suggesting a that these insects deal poorly with induced plant defences in potato.

Journal Article↗
PubMed2004

Distribution of ascorbic acid in potato tubers and in home-processed and commercial potato foods.

HPLC was used to analyze the content of ascorbic acid (AA) in tubers of four Korean potato cultivars (Chaju, Sumi, Deso, and Dejima), in a series of baked, boiled, braised, fried, microwaved, pressure-cooked, and sauteed potato slices from the Dejima cultivar and in 14 commercial Korean and 14 processed potato foods sold in the United States (chips, snacks, mashed potatoes, fries). The AA content for the four cultivars ranged from 16 to 46 mg/100 g of fresh weight. The distribution of AA in each of the eight potato slices (sticks, plugs) cut horizontally from the stem end of the Dejima potato ranged from 6.8 to 19.3% of the total. The corresponding distribution in seven sticks cut vertically was much narrower, ranging from 11.7 to 17.5% of the total. Losses of AA in water (pH 5.2) were significantly greater than in 5% metaphosphoric acid (pH 1.0). Less degradation occurred in water solutions of the vitamin stored at 1 degree C than at 25 degrees C. Losses of AA observed during home-processing of three varieties with low (Dejima, 16 mg/100 g), intermediate (Sumi, 32 mg/100 g), and high (Chaju, 42 mg/100 g) AA contents were as follows: boiling in water, 77-88%; boiling in water containing 1-3% NaCl, 61-79%; frying in oil, 55-79%; sauteing, 61-67%; pressure-cooking in water, 56-60%; braising, 50-63%; baking, 33-51%; and microwaving, 21-33%. The content of the Korean foods ranged from trace amounts to 25 mg/100 g and that of the U.S. foods from 0.4 to 46 mg/100 g. These results permit optimization of the vitamin C content of the diet by (a) using high-vitamin C potato varieties such as Chaju, (b) selecting sticks cut horizontally for frying, (c) baking or microwaving rather than boiling or frying, and (d) selecting commercial potato foods with a high vitamin C content.

Ascorbic Acid↗
PubMed2005

Comparison of several methods for the extraction of DNA from potatoes and potato-derived products.

Eight methods were compared for the extraction of DNA from raw potato tubers, and nine methods were evaluated for the extraction of DNA from dehydrated potato slices, potato flakes, potato flour, potato starch, and two ready-to-eat potato snack foods. Extracts were assessed for yield using a fluorescence-based DNA quantification assay. Real-time amplification of an endogenous gene, sucrose synthase (sus), was used to assess extract and template quality. A CTAB-based method extracted the highest DNA yields from the tuber material. An in-house method, which utilized the Kingfisher magnetic particle processor, yielded the highest template quality from the tubers. For most of the tuber samples, the Kingfisher and CTAB methods recovered the highest levels of amplifiable sus. DNA yields for potato-derived foods generally decreased with the extent that the product had been processed. The methods that utilized the magnetic particle processor delivered the highest template quality from one of the snack products that was particularly high in fat. For most of the remaining processed products, the levels of amplifiable target DNA recovered were roughly correlated with total DNA recovery, indicating that overall yield had greater influence over sus amplification than template quality. The Wizard method was generally the best method for the extraction of DNA from most of the potato-derived foods.

Cetrimonium↗
PubMed1999

Transformation of tobacco and potato with cDNA encoding the full-length genome of potato leafroll virus: evidence for a novel virus distribution and host effects on virus multiplication.

A full-length cDNA copy of the genome of Potato leafroll virus (PLRV) was introduced into the genome of tobacco and potato plants by Agrobacterium tumefaciens-mediated transformation. Transgenic lines were obtained in which the transgene was readily detected by PCR with DNA extracted from T(1) tobacco seedlings and clonally multiplied potato plants. PLRV-specific genomic and sub- genomic RNAs, coat protein antigen and virus particles were detected in transgenic plants. Aphids fed on the transgenic tobacco plants readily transmitted PLRV to test plants. Infected transgenic tobacco plants, like non-transgenic (WT) PLRV-infected plants, displayed no symptoms of the infection but transgenic plants of potato were severely stunted. In parallel tests, the mean PLRV titres in WT tobacco plants and transgenic tobacco plants were 600 and 630 ng virus/g leaf, respectively, although differences in PLRV titres among transgenic plants were much greater than those among infected WT plants. In similar tests with potato, the mean PLRV titre of WT plants was 50 ng virus/g leaf whereas higher concentrations (up to 3400 ng virus/g leaf) accumulated in transgenic potato plants. In tissue prints of stems, PLRV was detected in similar proportions of phloem cells in transgenic and infected WT plants. In transgenic tobacco and potato plants, but not in infected WT plants, a few stem epidermal cells also contained virus. From tissue prints of transgenic tobacco leaves, it was estimated that about one in 40000 mesophyll cells contained virus, but in transgenic potato, a greater proportion of mesophyll cells was infected.

DNA, Complementary↗
PubMed1998

The cysteine protease activity of Colorado potato beetle (Leptinotarsa decemlineata Say) guts, which is insensitive to potato protease inhibitors, is inhibited by thyroglobulin type-1 domain inhibitors.

High levels of protease inhibitors are induced in potato leaves by wounding. These inhibitors, when ingested by Colorado potato beetle (Leptinotarsa decemlineata Say) larvae, induce expression of specific proteolytic activities in the gut. Induced protease activities cannot be inhibited by potato inhibitors and thus enable the insects to overcome this defence mechanism of potato plants. The induced aminopeptidase and endoproteolytic activities both have the characteristics of cysteine proteases. Twenty-one protein inhibitors of different structural types have been examined for their ability to inhibit these activities in vitro. Members of the cystatin superfamily were found to be poor inhibitors of the induced endoproteolytic activities, except for the third domain of human kininogen, which was a fairly strong inhibitor (75% inhibition). The strongest inhibition (85%) of induced endoproteolytic activity was obtained using structurally different thyroglobulin type-1 domain-like inhibitors--equistatin and MHC class II-associated p41 invariant fragment. Experiments performed using three synthetic substrates for endoproteases gave similar results and indicate the existence of at least different endoproteolytic enzymes resistant to potato inhibitors. The induced aminopeptidase activity can be inhibited only by stefin family of inhibitors in cystatin superfamily. In in vivo experiments, Colorado potato beetle larvae fed on equistatin-coated potato leaves were strongly retarded in their growth and almost 50% died after 4 days. This demonstrated the potential of equistatin to protect crops from insect attack.

Animals↗
PubMed2000

Colorado potato beetle (Coleoptera: Chrysomelidae) feeding, development, and survival to adulthood after continuous exposure to Bacillus thuringiensis subsp. tenebrionis-treated potato foliage from the field.

Colorado potato beetle, Leptinotarsa decemlineata (Say), feeding, development, and survival to adulthood were examined after continuously exposing large larvae to Bacillus thuringiensis subsp. tenebrionis-treated potato foliage from the field. In laboratory assays, the overall consumption and the length of period to become prepupae were determined for larvae, which began as 3rd and 4th instars, that were offered potato leaf disks with naturally declining levels of B. thuringiensis residue. In small-cage field experiments, survival to adulthood and the period to adult emergence for beetles confined to potato plants treated with B. thuringiensis beginning as 3rd and 4th instars also were examined. Third instars remaining on plants after a B. thuringiensis application were unlikely to feed and 4th instars consumed only approximately 50% as much foliage as those fed untreated foliage. Many late instars subjected to B. thuringiensis-treated foliage failed to survive to adulthood; 58-83% of these beetles died during the larval stage. Reduced feeding and poor survival of late instars suggest that counts of large larvae after application do not provide a complete picture of the efficacy of the B. thuringiensis treatment. Late instar Colorado potato beetles that were exposed continually to naturally declining levels of B. thuringiensis-treated potato foliage took an average of 1.8-4.5 d longer to become prepupae and 4-8 d longer to emerge as adults compared with those provided with untreated foliage. Delayed emergence of adults that fed on B. thuringiensis-treated potatoes as late instars indicated that development was prolonged in these insects because of ingestion of a sublethal dose of B. thuringiensis.

Animals↗
PubMed2000

Microbiology of potatoes and potato products: a review.

Many types of spoilage and pathogenic microorganisms exist on fresh, minimally processed, and fully processed potato products. Potatoes are processed into many products including frozen, dried, ready-to-eat, and minimally processed. The microbiological quality of finished potato products is influenced by the natural microflora, processing, handling, and human contact. The natural microflora of potatoes are influenced by soil and airborne inocula, agricultural practices, harvesting methods, and storage conditions. The microflora of processed products are influenced by all of the factors and conditions affecting the natural microflora as well as the processes applied to the product. Increased consumer demand for new and existing potato products highlights the importance of ensuring their microbiological safety. This review considers the sources of microorganisms, microflora, foodborne disease pathogens, and outbreaks associated with, and selected microbiological research involving, potatoes and potato products.

Consumer Advocacy↗
PubMed2004

Transgenic-Bt potato plant resistance to the colorado potato beetle affect the aphid parasitoid Aphidius nigripes.

Using the biotechnological plant resistance for herbivore control with less reliance on chemicals in integrated pest management (IPM) programs critically depends on predictable interactions with no-target organisms of various trophic levels. Plant resistance to insect pests based on recombinant Bacillus thuringiensis could interfere with natural enemies of non target pests. Performance of the potato aphid parasitoid Aphidius nigripes was studied on the 'Superior-BT line transgenic for the CryllIA toxin of B. thuringiensis, resistance to the Colorado potato beetle; and none transformed 'Superior' line which served as control. Parasitoid survival was significantly lower on the 'Superior-BT' line compared to control. Adult females were largest on 'Superior' and smallest on BT potatoes. This difference was reflected on parasitoid fecundity, which was lowest on 'Superior-BT', and highest on Superior. The results indicate that factor of potato resistance to the Colorado potato beetle affected the fitness of a parasitold of the aphid Macrosiphum euphorbiae, a secondary pest of potato. The effects on the parasitoid were complex but were generally interpretable in terms of host aphid quality variation among potato lines used as food by the aphids during parasitoid development.

Animals↗
PubMed2004

Seasonal occurrence and relative abundance of aphids on potato plants with classical and transgenic characters of resistance to Colorado potato beetle Leptinotarsa decemlineata (Say).

The seasonal abundance and dynamics of potato-infesting aphids were studied in two seasons, on potato Solanum tuberosum L. with various types of transgenic and classical resistance to primary pests, especially the Colorado potato beetle (CPB), Leptinotarsa decemlineata (Say). The lines tested were the NewLeaf potato, a transgenic expressing the Bacillus thuringiensis CryIIIA toxin (BTT); NYL 235-4 a parental line derived from S. berthaultii (NYL) with a high density of glandular trichomes; and a transgenic line expressing oryzacystatln I (OCI), a proteinase inhibitor gene from rice; potatoes from two commercial cultivars, Superior and Kennebec, served as controls. Over the two seasons, Macrosiphum euphorbiae (Thomas) and, to a lesser extent, Myzus persicae (Sulzer) were by far the most abundant aphids observed in the experimental plots. M. persicae was observed relatively late in the season, and was most abundant on the Kennebec-OCI potato. Macrosiphum euphorbiae was more regular over seasons, and its highest densities were observed on the NYL 235-4 line. The population of M. euphorbiae showed markedly different patterns on the five lines studied, which was clearly related to potato plant phenology. Density of M. euphorbiae was observed on the NYL 235-4 line, in late July and early August.

Animals↗
PubMed2005

[Cloning, Characterization and Expression Vector Construction of Potato Proteas-inhibitor II Gene (PIN II-2x) from Diploid Potato (Solanum phurejia).].

Based on the published gene sequence of tetraploid potato (Solanum.tuberosum) protease-inhibitor II, a genomic DNA and a cDNA sequence of potato protease-inhibitor II gene were obtained from the cDNA library and the genomic DNA of a diploid potato IVP101 (Solanum.phurejia) using PCR method and named PINII-2x. Nucleotide sequencing confirmed that the full-length DNA of PINII-2x was 580 bp, including an 115 bp intron and two exons. cDNA was 462 bp ( stop codon TGA not included) and had 88% similarity to the tetraploid potato protease-inhibitor II. The PINII-2x open reading frame encodes a 154-amino acid polypeptide with a predicated size of 16.6 KD and a calculated PI of 6.08. The deduced proteins from PINII-2x cDNA had 93% homology with other tetraploid potato protease-inhibitor II, which contain the intact signal peptide and two active site similar to the potato protease-inhibitor II family. Test of the RT-PCR indicated that PINII-2x mRNA is wound- induced expression in potato leaves. Binary vector of PINII-2x cDNA drove by either rice Actin I promoter (ActI) or maize Ubiquitin promoter (Ubi) was constructed.

Amino Acid Sequence↗
PubMed2000

Adult Colorado potato beetles, Leptinotarsa decemlineata compensate for nutritional stress on oryzacystatin I-transgenic potato plants by hypertrophic behavior and over-production of insensitive proteases.

Protease inhibitors have been proposed as potential control molecules that could be engineered into potato plants for developing crops resistant to the Colorado potato beetle, Leptinotarsa decemlineata, a major pest of potato and other Solanaceae. In this study, we examined the effects of feeding young female beetles with foliage from a cultivar of the "Kennebec" potato line (K52) transformed with a gene encoding oryzacystatin I (OCI), a specific cysteine proteinase inhibitor with proven activity against cathepsin H-like enzymes of larvae and adults of the potato beetle. To evaluate the insect's performance, we collected data over a 16-d postemergence period on survival, diapause incidence, foliage consumption, weight gain, and oviposition of females. Tested individuals were fed untransformed (control) and OCI-transformed foliage at two stages of potato leaf differentiation, corresponding to "low" and "high" levels of OCI expression in leaves of K52. The OCI-expressing foliage did not affect female survival (close to 100%), incidence of diapause (15-30%), relative growth rate (RGR) during postemergence growth (5-9% d(-1)) or maximum weight reached (140-160 mg). Neither did it affect female reproductive fitness as measured by preoviposition time (8-9 d), 16-d fecundity (220-290 eggs), or egg eclosion incidence (86-91%). However, nutritional stress to females feeding on OCI foliage was evident, as reflected in their lower efficiency of conversion of ingested foliage (ECI) during postemergence growth, increased foliage consumed per egg laid (up to 119% more), and adaptation of their digestive proteolytic system to the inhibitory effect of OCI. Interestingly, beetles fed foliage expressing the highest level of OCI reacted rapidly to the presence of OCI by producing OCI-insensitive proteases, and exhibiting strong hypertrophic behavior by ingestion of 2.4-2.5 times more OCI rich foliage apparently as a compensatory response for nutritional stress due to the protease inhibitor in their diet.

Animals↗
PubMed2006

Potato chromosomes IX and XI carry genes for resistance to potato virus M.

Two new loci for resistance to potato virus M (PVM), Gm and Rm, have been mapped in potato. The gene Gm was derived from Solanum gourlayi, whereas, Solanum megistacrolobum is the source of the gene Rm. Gm confers resistance to PVM infection after mechanical inoculation. Rm induces a hypersensitive response in potato plants. Two diploid populations segregating for Gm and Rm, bulked segregant analysis (BSA) using random amplified polymorphic DNA (RAPD) and inter-simple sequence repeat (ISSR), and available potato molecular maps were instrumental for mapping the resistance loci. The novel locus Gm was mapped to a central region on potato chromosome IX. The locus Rm was placed on the short arm of chromosome XI, close to the marker loci GP250 and GP283, where a hotspot for monogenic and polygenic resistance to diverse pathogens is located in the potato and tomato genome.

Carlavirus↗
PubMed2005

Unexpected effects of chitinases on the peach-potato aphid (Myzus persicae Sulzer) when delivered via transgenic potato plants (Solanum tuberosum Linné) and in vitro.

With the aim of producing insect-resistant potato plants, internode explants of Solanum tuberosum L. cv. Désirée were transformed with an Agrobacterium strain C58pMP90 containing an insect (Phaedon cochleariae: Coleoptera, Chrysomelidae) chitinase gene and the neomycin phosphotransferase (nptII) gene as selectable marker, both under the control of the viral CaMV 35S promoter. Three transformed potato lines (CH3, CH5 and CH25) exhibiting the highest chitinolytic activities were selected for feeding experiments with the peach-potato aphid, Myzus persicae (Sulzer), under controlled photoperiod and temperature conditions. Aphids fed on transgenic potato plants showed a reduced pre-reproductive period and an enhanced daily fecundity. Transgenic potato lines did not affect nymphal mortality, but improved several biological parameters related to aphid population's growth. Artificial diets were used to provide active (1, 10, 100 and 500 microg ml(-1)) and inactive (500 microg ml(-1)) bacterial (Serratia marcescens) chitinase to M. persicae. These compounds increased nymph survival at all active chitinase doses when compared to the control diet, while inactive chitinase did not. Although the pre-reproductive period was slightly shortened and the daily fecundity slightly higher, active and inactive chitinase provided as food led a reduction from 1 to 1.5 day population's doubling time. Therefore chitinase activity was responsible for the probiotic effects on aphids. Our results question the relevance of a chitinase-based strategy in the context of potato culture protection.

Animals↗
PubMed1975

[Studies on growing pigs to determine the true digestibility of variously prepared potatoes. 2. Technically dried potatoes].

There are two kinds of damage to potato proteins that may arise in the process of beat drying. Decreases in the gross lysine content are accompanied by a still much more pronounced depression of digestibility. If, for example, the gross lysine content of dried potatoes was only 50% of that of steamed potatoes then the average value for the true lysine digestibility was 15%; in some cases the content of truly digestible lysine was 0% when compared to that of steamed potatoes. Similarly, it was found that some types of dried potatoes with a dry matter content of about 88% had already lost about 43% of the truly digestible lysine contained in steamed potatoes.

Animal Nutritional Physiological Phenomena↗