Altering Trehalose-6-Phosphate Content in Transgenic Potato Tubers Affects Tuber Growth and Alters Responsiveness to Hormones during Sprouting

Debast S, Nunes-Nesi A, Hajirezaei MR, Hofmann J, Sonnewald U, Fernie AR, Börnke F (2011)

Publication Status: Published

Publication Type: Journal article

Publication year: 2011

Journal

Publisher: AMER SOC PLANT BIOLOGISTS

Book Volume: 156

Pages Range: 1754-1771

Journal Issue: 4

DOI: 10.1104/pp.111.179903

Abstract

Trehalose-6-phosphate (T6P) is a signaling metabolite that regulates carbon metabolism, developmental processes, and growth in plants. In Arabidopsis (Arabidopsis thaliana), T6P signaling is, at least in part, mediated through inhibition of the SNF1-related protein kinase SnRK1. To investigate the role of T6P signaling in a heterotrophic, starch-accumulating storage organ, transgenic potato (Solanum tuberosum) plants with altered T6P levels specifically in their tubers were generated. Transgenic lines with elevated T6P levels (B33-TPS, expressing Escherichia coli osmoregulatory trehalose synthesis A [OtsA], which encodes a T6P synthase) displayed reduced starch content, decreased ATP contents, and increased respiration rate diagnostic for high metabolic activity. On the other hand, lines with significantly reduced T6P (B33-TPP, expressing E. coli OtsB, which encodes a T6P phosphatase) showed accumulation of soluble carbohydrates, hexose phosphates, and ATP, no change in starch when calculated on a fresh weight basis, and a strongly reduced tuber yield. [C-14] Glucose feeding to transgenic tubers indicated that carbon partitioning between starch and soluble carbohydrates was not altered. Transcriptional profiling of B33-TPP tubers revealed that target genes of SnRK1 were strongly up-regulated and that T6P inhibited potato tuber SnRK1 activity in vitro. Among the SnRK1 target genes in B33-TPP tubers, those involved in the promotion of cell proliferation and growth were down-regulated, while an inhibitor of cell cycle progression was up-regulated. T6P-accumulating tubers were strongly delayed in sprouting, while those with reduced T6P sprouted earlier than the wild type. Early sprouting of B33-TPP tubers correlated with a reduced abscisic acid content. Collectively, our data indicate that T6P plays an important role for potato tuber growth.

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Involved external institutions

Max-Planck-Institut für molekulare Pflanzenphysiologie / Max Planck Institute of Molecular Plant Physiology Germany (DE) Leibniz-Institut für Pflanzengenetik und Kulturpflanzenforschung (IPK) / Leibniz Institute of Plant Genetics and Crop Plant Research Germany (DE)

How to cite

APA:

Debast, S., Nunes-Nesi, A., Hajirezaei, M.R., Hofmann, J., Sonnewald, U., Fernie, A.R., & Börnke, F. (2011). Altering Trehalose-6-Phosphate Content in Transgenic Potato Tubers Affects Tuber Growth and Alters Responsiveness to Hormones during Sprouting. Plant Physiology, 156(4), 1754-1771. https://doi.org/10.1104/pp.111.179903

MLA:

Debast, Stefan, et al. "Altering Trehalose-6-Phosphate Content in Transgenic Potato Tubers Affects Tuber Growth and Alters Responsiveness to Hormones during Sprouting." Plant Physiology 156.4 (2011): 1754-1771.

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