Homeostasis of branched-chain amino acids is critical for the activity of TOR signaling in Arabidopsis
- Michigan State University, United States
Abstract
The target of rapamycin (TOR) kinase is an evolutionarily conserved hub of nutrient sensing and metabolic signaling. In plants, a functional connection of TOR activation with glucose availability was demonstrated, while it is yet unclear whether branched-chain amino acids (BCAAs) are a primary input of TOR signaling as they are in yeast and mammalian cells. Here, we report on the characterization of an Arabidopsis mutant over-accumulating BCAAs. Through chemical interventions targeting TOR and by examining mutants of BCAA biosynthesis and TOR signaling, we found that BCAA over-accumulation leads to up-regulation of TOR activity, which causes reorganization of the actin cytoskeleton and actin-associated endomembranes. Finally, we show that activation of TOR is concomitant with alteration of cell expansion, proliferation and specialized metabolism, leading to pleiotropic effects on plant growth and development. These results demonstrate that BCAAs contribute to plant TOR activation and reveal previously uncharted downstream subcellular processes of TOR signaling.
Data availability
All data generated or analyzed in this study have been included in the manuscript and the supporting files.
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Author details
Federica Brandizzi
Funding
National Science Foundation (MCB1727362)
- Federica Brandizzi
National Institute of Food and Agriculture (MICL02299)
- Federica Brandizzi
National Science Foundation (NPGI-1811055)
- Craig A Schenck
U.S. Department of Energy (DE-FG02-91ER20021)
- Federica Brandizzi
U.S. Department of Energy (DE-FC02-07ER64494)
- Federica Brandizzi
The funders had no role in study design, data collection and interpretation, or the decision to submit the work for publication.
Copyright
© 2019, Cao et al.
This article is distributed under the terms of the Creative Commons Attribution License permitting unrestricted use and redistribution provided that the original author and source are credited.
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Homeostasis of branched-chain amino acids is critical for the activity of TOR signaling in Arabidopsis
eLife 8:e50747.
https://doi.org/10.7554/eLife.50747
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