Acknowledgements
We thank Allison Hutt, Nick Ryan, Brady Lee and members of the Juenger Laboratory for their assistance in experiment preparation, plant phenotyping and sample collection. This work was supported by a National Science Foundation Plant Genome Research Program award to T.E.J. (IOS-1444533) and by the US Department of Energy, Office of Science, Office of Biological and Environmental Research Award DESC0014156 to T.E.J