Downregulation of chloroplast-targeted beta-amylase leads to a starch-excess phenotype in leaves

A. Scheidig, A. Fröhlich, S. Schulze, J.R. Lloyd, Jens Matthias Kossmann

    Research output: Contribution to journalJournal articleResearchpeer-review

    Abstract

    A functional screen in Escherichia coli was established to identify potato genes coding for proteins involved in transitory starch degradation. One clone isolated had a sequence very similar to a recently described chloroplast-targeted 5-amylase of Arabidopsis. Expression of the gene in E. coli showed that the protein product was a functional beta-amylase that could degrade both starch granules and solubilized amylopectin, while import experiments demonstrated that the beta-amylase was imported and processed into pea chloroplasts. To study the function of the protein in transitory starch degradation, transgenic potato plants were generated where its activity was reduced using antisense techniques. Analysis of plants reduced in the presence of this beta-amylase isoform showed that their leaves had a starch-excess phenotype, indicating a defect in starch degradation. In addition, it was shown that the antisense plants degraded only 8-30% of their total starch, in comparison with 50% in the wild type, over the dark period. This is the first time that a physiological role for a beta-amylase in plants has been demonstrated.
    Original languageEnglish
    JournalPlant Journal
    Volume30
    Issue number5
    Pages (from-to)581-591
    ISSN0960-7412
    DOIs
    Publication statusPublished - 2002

    Cite this

    Scheidig, A. ; Fröhlich, A. ; Schulze, S. ; Lloyd, J.R. ; Kossmann, Jens Matthias. / Downregulation of chloroplast-targeted beta-amylase leads to a starch-excess phenotype in leaves. In: Plant Journal. 2002 ; Vol. 30, No. 5. pp. 581-591.
    @article{b27bba4c06f84d159a895ab8ab454d71,
    title = "Downregulation of chloroplast-targeted beta-amylase leads to a starch-excess phenotype in leaves",
    abstract = "A functional screen in Escherichia coli was established to identify potato genes coding for proteins involved in transitory starch degradation. One clone isolated had a sequence very similar to a recently described chloroplast-targeted 5-amylase of Arabidopsis. Expression of the gene in E. coli showed that the protein product was a functional beta-amylase that could degrade both starch granules and solubilized amylopectin, while import experiments demonstrated that the beta-amylase was imported and processed into pea chloroplasts. To study the function of the protein in transitory starch degradation, transgenic potato plants were generated where its activity was reduced using antisense techniques. Analysis of plants reduced in the presence of this beta-amylase isoform showed that their leaves had a starch-excess phenotype, indicating a defect in starch degradation. In addition, it was shown that the antisense plants degraded only 8-30{\%} of their total starch, in comparison with 50{\%} in the wild type, over the dark period. This is the first time that a physiological role for a beta-amylase in plants has been demonstrated.",
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    author = "A. Scheidig and A. Fr{\"o}hlich and S. Schulze and J.R. Lloyd and Kossmann, {Jens Matthias}",
    year = "2002",
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    language = "English",
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    Scheidig, A, Fröhlich, A, Schulze, S, Lloyd, JR & Kossmann, JM 2002, 'Downregulation of chloroplast-targeted beta-amylase leads to a starch-excess phenotype in leaves', Plant Journal, vol. 30, no. 5, pp. 581-591. https://doi.org/10.1046/j.1365-313X.2002.01317.x

    Downregulation of chloroplast-targeted beta-amylase leads to a starch-excess phenotype in leaves. / Scheidig, A.; Fröhlich, A.; Schulze, S.; Lloyd, J.R.; Kossmann, Jens Matthias.

    In: Plant Journal, Vol. 30, No. 5, 2002, p. 581-591.

    Research output: Contribution to journalJournal articleResearchpeer-review

    TY - JOUR

    T1 - Downregulation of chloroplast-targeted beta-amylase leads to a starch-excess phenotype in leaves

    AU - Scheidig, A.

    AU - Fröhlich, A.

    AU - Schulze, S.

    AU - Lloyd, J.R.

    AU - Kossmann, Jens Matthias

    PY - 2002

    Y1 - 2002

    N2 - A functional screen in Escherichia coli was established to identify potato genes coding for proteins involved in transitory starch degradation. One clone isolated had a sequence very similar to a recently described chloroplast-targeted 5-amylase of Arabidopsis. Expression of the gene in E. coli showed that the protein product was a functional beta-amylase that could degrade both starch granules and solubilized amylopectin, while import experiments demonstrated that the beta-amylase was imported and processed into pea chloroplasts. To study the function of the protein in transitory starch degradation, transgenic potato plants were generated where its activity was reduced using antisense techniques. Analysis of plants reduced in the presence of this beta-amylase isoform showed that their leaves had a starch-excess phenotype, indicating a defect in starch degradation. In addition, it was shown that the antisense plants degraded only 8-30% of their total starch, in comparison with 50% in the wild type, over the dark period. This is the first time that a physiological role for a beta-amylase in plants has been demonstrated.

    AB - A functional screen in Escherichia coli was established to identify potato genes coding for proteins involved in transitory starch degradation. One clone isolated had a sequence very similar to a recently described chloroplast-targeted 5-amylase of Arabidopsis. Expression of the gene in E. coli showed that the protein product was a functional beta-amylase that could degrade both starch granules and solubilized amylopectin, while import experiments demonstrated that the beta-amylase was imported and processed into pea chloroplasts. To study the function of the protein in transitory starch degradation, transgenic potato plants were generated where its activity was reduced using antisense techniques. Analysis of plants reduced in the presence of this beta-amylase isoform showed that their leaves had a starch-excess phenotype, indicating a defect in starch degradation. In addition, it was shown that the antisense plants degraded only 8-30% of their total starch, in comparison with 50% in the wild type, over the dark period. This is the first time that a physiological role for a beta-amylase in plants has been demonstrated.

    KW - 8-B gen

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    DO - 10.1046/j.1365-313X.2002.01317.x

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    VL - 30

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    EP - 591

    JO - Plant Journal

    JF - Plant Journal

    SN - 0960-7412

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