Addition/Correction pubs.acs.org/ac
Correction to Transcription Factor Sensor System for Parallel Quantification of Metabolites On-Chip Simon Ketterer, Désirée Hövermann, Raphael J. Guebeli, Frauke Bartels-Burgahn, David Riewe, Thomas Altmann, Matias D. Zurbriggen, Björn Junker, Wilfried Weber,* and Matthias Meier* Anal. Chem. 2014, 86, 12152−12158. DOI: 10.1021/ac503269m
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and T6P concentration within the Arabidopsis sample of 133 ± 9 nmol/g FW and 5.8 ± 0.4 nmol/g FW, respectively. These concentrations matched with previous literature values, which were between 50−150 nmol/g and 0.1−6 FW, respectively.1−3 However, other contributions from the sample matrix on the absolute quantification of the metabolites cannot be excluded. Therefore, changes of pyruvate and T6P during the diurnal cycle within Arabidopsis rosettes in Figure 4B can only be given as relative values. For determination of the relative changes of pyruvate and T6P, the reference approach described in the manuscript is valid. In consequence, Figure 4 on page 12157 of the original manuscript should be as follows.
he authors noted that the reference curves in Figure 4 of the original paper for determining the absolute concen-
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REFERENCES
(1) Carillo, P.; Feil, R.; Gibon, Y.; Satoh-Nagasawa, N.; Jackson, D.; Bläsing, O. E.; Stitt, M.; Lunn, J. E. Plant Methods 2013, 9, 21. (2) Nunes, C.; O’Hara, L. E.; Primavesi, L. F.; Delatte, T. L.; Schluepmann, H.; Somsen, G. W.; Silva, A. B.; Fevereiro, P. S.; Wingler, A.; Paul, M. J. Plant Physiol. 2013, 162, 1720. (3) Voll, L.; Hausler, R. E.; Hecker, R.; Weber, A.; Weissenbock, G.; Fiene, G.; Waffenschmidt, S.; Flugge, U.-I. Plant J. 2003, 36, 301.
Figure 4. Determination of pyruvate and T6P concentration within an extract of cells from Arabidopsis rosettes. Fluorescent signal of DNA bound (A) TreR and (B) PdhR in the reference (R) and dilutions of the analytical sample (S) plotted against the metabolite concentrations of the reference samples, respectively. T6P concentrations of either 8 or 20 μmol/L were spiked-in. The dilution factor for the T6P and pyruvate samples were f = 9;3;1.8;1.28;1 and 33;13;6;3;2;1.5;1.2;1, respectively. (C) Relative diurnal changes of the T6P and pyruvate concentration within rosettes from 5 week-old Arabidopsis plants measured within one chip experiment. Yellow and gray areas in the plot denote the light and dark phases, respectively.
tration of pyruvate and T6P exhibited an offset to the analyte sample due to a mismatch of the buffer conditions. To compensate for the difference, we prepared an aliquot of the plant extract in which pyruvate and T6P were degraded by addition of trehalose-6-phosphate hydrolase (350 U/mL, Prozomix, U.K.) and lactate-dehydrogenase (500 U/mL, Sigma Aldrich Germany) dissolved in degradation buffer (250 mM NaCl, 20 mM MgCl2, 50 mM Tris pH 7.6, 1 mM NADH, 0.05% v/v Tween20), respectively. After an incubation step of 4 h at 37 °C, both enzymes were heat inactivated. The aliquot with the degraded metabolites was then subsequently added to the reference sample until it contained the same cell extract concentration as the analyte sample. With the adjusted buffer conditions for the reference sample, we determined a pyruvate © 2015 American Chemical Society
Published: July 24, 2015 8034
DOI: 10.1021/acs.analchem.5b02553 Anal. Chem. 2015, 87, 8034−8034
