skip to main content
OSTI.GOV title logo U.S. Department of Energy
Office of Scientific and Technical Information

Title: Reduced Arogenate Dehydratase Expression: Ramifications for Photosynthesis and Metabolism

Abstract

Arogenate dehydratase (ADT) catalyzes the final step of phenylalanine biosynthesis. Previously, lignin contents of ADT deficient Arabidopsis thaliana mutant plants were measured, with these showing significant reductions that increased with the number of isoforms knocked-out. Here we describe the effects of ADT modulation on photosynthetic parameters and overall secondary metabolism in short day length grown plants. To do this, we employed our phenomics facility to determine significant effects on photosynthetic parameters. The data indicated that reduction of carbon flux into phenylalanine biosynthesis in ADT mutants impairs consumption of photosynthetically produced ATP leading to increased ATP/ADP ratio and over-accumulation of transitory starch and lower electron transport rates. The latter is caused by an increased proton motive force across the thylakoid membrane that activates down-regulation of photosystem II activity by the high energy quenching mechanism. At the same time, we have used UPLC-MS based metabolomics analyses to determine changes in secondary metabolite contents. Using this approach, the systemic effects of ADT modulation became apparent, establishing a reduction in flavonoid, phenylpropanoid, lignan and glucosinolate contents; this included glucosinolates that were not aromatic amino acid derived. On the other hand, we observed a significant increase in putatively annotated galactolipids and apocarotenoids. Additionally, we usedmore » real-time atmospheric monitoring mass spectrometry to measure differential respiration and carbon fixation rates between wild-type plants and our most extreme ADT knock-out mutant, adt3/4/5/6. We observed that respiration rates were not significantly, different but carbon fixation rates in the adt3/4/5/6 mutant were higher than in wild-type.« less

Authors:
; ; ; ; ; ; ; ; ;
Publication Date:
Research Org.:
Pacific Northwest National Lab. (PNNL), Richland, WA (United States)
Sponsoring Org.:
USDOE
OSTI Identifier:
1503546
Report Number(s):
PNNL-SA-131412
Journal ID: ISSN 0032-0889
DOE Contract Number:  
AC05-76RL01830
Resource Type:
Journal Article
Journal Name:
Plant Physiology (Bethesda)
Additional Journal Information:
Journal Volume: 177; Journal Issue: 1; Journal ID: ISSN 0032-0889
Publisher:
American Society of Plant Biologists
Country of Publication:
United States
Language:
English
Subject:
phenylpropanoid, arogenate dehydratase, photosynthesis, secondary metabolism, gene knockout

Citation Formats

Höhner, Ricarda, Marques, Joaquim V., Ito, Tetsuro, Amakura, Yoshiaki, Budgeon, Alan D., Weitz, Karl, Hixson, Kim K., Davin, Laurence B., Kirchhoff, Helmut, and Lewis, Norman G. Reduced Arogenate Dehydratase Expression: Ramifications for Photosynthesis and Metabolism. United States: N. p., 2018. Web. doi:10.1104/pp.17.01766.
Höhner, Ricarda, Marques, Joaquim V., Ito, Tetsuro, Amakura, Yoshiaki, Budgeon, Alan D., Weitz, Karl, Hixson, Kim K., Davin, Laurence B., Kirchhoff, Helmut, & Lewis, Norman G. Reduced Arogenate Dehydratase Expression: Ramifications for Photosynthesis and Metabolism. United States. doi:10.1104/pp.17.01766.
Höhner, Ricarda, Marques, Joaquim V., Ito, Tetsuro, Amakura, Yoshiaki, Budgeon, Alan D., Weitz, Karl, Hixson, Kim K., Davin, Laurence B., Kirchhoff, Helmut, and Lewis, Norman G. Fri . "Reduced Arogenate Dehydratase Expression: Ramifications for Photosynthesis and Metabolism". United States. doi:10.1104/pp.17.01766.
@article{osti_1503546,
title = {Reduced Arogenate Dehydratase Expression: Ramifications for Photosynthesis and Metabolism},
author = {Höhner, Ricarda and Marques, Joaquim V. and Ito, Tetsuro and Amakura, Yoshiaki and Budgeon, Alan D. and Weitz, Karl and Hixson, Kim K. and Davin, Laurence B. and Kirchhoff, Helmut and Lewis, Norman G.},
abstractNote = {Arogenate dehydratase (ADT) catalyzes the final step of phenylalanine biosynthesis. Previously, lignin contents of ADT deficient Arabidopsis thaliana mutant plants were measured, with these showing significant reductions that increased with the number of isoforms knocked-out. Here we describe the effects of ADT modulation on photosynthetic parameters and overall secondary metabolism in short day length grown plants. To do this, we employed our phenomics facility to determine significant effects on photosynthetic parameters. The data indicated that reduction of carbon flux into phenylalanine biosynthesis in ADT mutants impairs consumption of photosynthetically produced ATP leading to increased ATP/ADP ratio and over-accumulation of transitory starch and lower electron transport rates. The latter is caused by an increased proton motive force across the thylakoid membrane that activates down-regulation of photosystem II activity by the high energy quenching mechanism. At the same time, we have used UPLC-MS based metabolomics analyses to determine changes in secondary metabolite contents. Using this approach, the systemic effects of ADT modulation became apparent, establishing a reduction in flavonoid, phenylpropanoid, lignan and glucosinolate contents; this included glucosinolates that were not aromatic amino acid derived. On the other hand, we observed a significant increase in putatively annotated galactolipids and apocarotenoids. Additionally, we used real-time atmospheric monitoring mass spectrometry to measure differential respiration and carbon fixation rates between wild-type plants and our most extreme ADT knock-out mutant, adt3/4/5/6. We observed that respiration rates were not significantly, different but carbon fixation rates in the adt3/4/5/6 mutant were higher than in wild-type.},
doi = {10.1104/pp.17.01766},
journal = {Plant Physiology (Bethesda)},
issn = {0032-0889},
number = 1,
volume = 177,
place = {United States},
year = {2018},
month = {3}
}