43
views
0
recommends
+1 Recommend
0 collections
    0
    shares
      • Record: found
      • Abstract: found
      • Article: found
      Is Open Access

      Sugar metabolism, chip color, invertase activity, and gene expression during long-term cold storage of potato ( Solanum tuberosum) tubers from wild-type and vacuolar invertase silencing lines of Katahdin

      research-article

      Read this article at

      Bookmark
          There is no author summary for this article yet. Authors can add summaries to their articles on ScienceOpen to make them more accessible to a non-specialist audience.

          Abstract

          Background

          Storing potato tubers at low temperatures minimizes sprouting and disease but can cause an accumulation of reducing sugars in a process called cold-induced sweetening. Tubers with increased amounts of reducing sugars produce dark-colored, bitter-tasting fried products with elevated amounts of acrylamide, a possible carcinogen. Vacuolar invertase (VInv), which converts sucrose produced by starch breakdown to glucose and fructose, is the key determinant of reducing sugar accumulation during cold-induced sweetening. In this study, wild-type tubers and tubers in which VInv expression was reduced by RNA interference were used to investigate time- and temperature-dependent changes in sugar contents, chip color, and expression of VInv and other genes involved in starch metabolism in tubers during long-term cold storage.

          Results

          VInv activities and tuber reducing sugar contents were much lower, and tuber sucrose contents were much higher, in transgenic than in wild-type tubers stored at 3-9°C for up to eight months. Large differences in VInv mRNA accumulation were not observed at later times in storage, especially at temperatures below 9°C, so differences in invertase activity were likely established early in the storage period and maintained by stability of the invertase protein. Sugar contents, chip color, and expression of several of the studied genes, including AGPase and GBSS, were affected by storage temperature in both wild-type and transgenic tubers. Though transcript accumulation for other sugar-metabolism genes was affected by storage temperature and duration, it was essentially unaffected by invertase silencing and altered sugar contents. Differences in stem- and bud-end sugar contents in wild-type and transgenic tubers suggested different compartmentalization of sucrose at the two ends of stored tubers.

          Conclusions

          VInv silencing significantly reduced cold-induced sweetening in stored potato tubers, likely by means of differential VInv expression early in storage. Transgenic tubers retained sensitivity to storage temperature, and accumulated greater amounts of sucrose, glucose and fructose at 3°C than at 7-9°C. At each storage temperature, suppression of VInv expression and large differences in tuber sugar contents had no effect on expression of AGPase and GBSS, genes involved in starch metabolism, suggesting that transcription of these genes is not regulated by tuber sugar content.

          Related collections

          Most cited references24

          • Record: found
          • Abstract: found
          • Article: not found

          Suppression of the vacuolar invertase gene prevents cold-induced sweetening in potato.

          Potato (Solanum tuberosum) is the third most important food crop in the world. Potato tubers must be stored at cold temperatures to prevent sprouting, minimize disease losses, and supply consumers and the processing industry with high-quality tubers throughout the year. Unfortunately, cold storage triggers an accumulation of reducing sugars in tubers. High-temperature processing of these tubers results in dark-colored, bitter-tasting products. Such products also have elevated amounts of acrylamide, a neurotoxin and potential carcinogen. We demonstrate that silencing the potato vacuolar acid invertase gene VInv prevents reducing sugar accumulation in cold-stored tubers. Potato chips processed from VInv silencing lines showed a 15-fold acrylamide reduction and were light in color even when tubers were stored at 4°C. Comparable, low levels of VInv gene expression were observed in cold-stored tubers from wild potato germplasm stocks that are resistant to cold-induced sweetening. Thus, both processing quality and acrylamide problems in potato can be controlled effectively by suppression of the VInv gene through biotechnology or targeted breeding.
            Bookmark
            • Record: found
            • Abstract: not found
            • Article: not found

            An overview of the factors affecting sugar content of potatoes

              Bookmark
              • Record: found
              • Abstract: found
              • Article: not found

              Concentrations of free amino acids and sugars in nine potato varieties: effects of storage and relationship with acrylamide formation.

              Acrylamide forms during cooking and processing predominately from the reaction of free asparagine and reducing sugars in the Maillard reaction. The identification of low free asparagine and reducing sugar varieties of crops is therefore an important target. In this study, nine varieties of potato (French fry varieties Maris Piper (from two suppliers), Pentland Dell, King Edward, Daisy, and Markies; and chipping varieties Lady Claire, Lady Rosetta, Saturna, and Hermes) grown in the United Kingdom in 2009 were analyzed at monthly intervals through storage from November 2009 to July 2010. Acrylamide formation was measured in heated flour and chips fried in oil. Analysis of variance revealed significant interactions between varieties nested within type (French fry and chipping) and storage time for most free amino acids, glucose, fructose, and acrylamide formation. Acrylamide formed in chips correlated significantly with acrylamide formed in flour and with chip color. There were significant correlations between glucose or total reducing sugar concentration and acrylamide formation in both variety types, but with fructose the correlation was much stronger for chipping than for French fry varieties. Conversely, there were significant correlations with acrylamide formation for both total free amino acid and free asparagine concentration in the French fry but not chipping varieties. The study showed the potential of variety selection for preventing unacceptable levels of acrylamide formation in potato products and the variety-dependent effect of long-term storage on acrylamide risk. It also highlighted the complex relationship between precursor concentration and acrylamide risk in potatoes.
                Bookmark

                Author and article information

                Contributors
                aewiberley@wisc.edu
                james.busse@ars.usda.gov
                jjiang1@wisc.edu
                pbethke@wisc.edu
                Journal
                BMC Res Notes
                BMC Res Notes
                BMC Research Notes
                BioMed Central (London )
                1756-0500
                16 November 2014
                16 November 2014
                2014
                : 7
                : 1
                : 801
                Affiliations
                [ ]United States Department of Agriculture – Agricultural Research Service, Vegetable Crops Research Unit, 1575 Linden Dr., Madison, WI 53706 USA
                [ ]Department of Horticulture, University of Wisconsin-Madison, 1575 Linden Dr., Madison, WI 53706 USA
                Article
                3320
                10.1186/1756-0500-7-801
                4239387
                25399251
                e0a3cf91-4257-4f77-a004-4e49bd9b313c
                © Wiberley-Bradford et al.; licensee BioMed Central Ltd. 2014

                This article is published under license to BioMed Central Ltd. This is an Open Access article distributed under the terms of the Creative Commons Attribution License ( http://creativecommons.org/licenses/by/4.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly credited. The Creative Commons Public Domain Dedication waiver ( http://creativecommons.org/publicdomain/zero/1.0/) applies to the data made available in this article, unless otherwise stated.

                History
                : 25 July 2014
                : 24 October 2014
                Categories
                Research Article
                Custom metadata
                © The Author(s) 2014

                Medicine
                vacuolar invertase,potato,sugar metabolism,cold storage,starch synthase,sucrose synthase,invertase inhibitor,adp-glucose pyrophosphorylase,potato chip processing quality

                Comments

                Comment on this article

                scite_
                0
                0
                0
                0
                Smart Citations
                0
                0
                0
                0
                Citing PublicationsSupportingMentioningContrasting
                View Citations

                See how this article has been cited at scite.ai

                scite shows how a scientific paper has been cited by providing the context of the citation, a classification describing whether it supports, mentions, or contrasts the cited claim, and a label indicating in which section the citation was made.

                Similar content166

                Cited by13

                Most referenced authors320