@article{dc781fae0e68414fb9adb63b37c8ba94,
title = "A minimally disruptive method for measuring water potential in planta using hydrogel nanoreporters",
abstract = "Leaf water potential is a critical indicator of plant water status, integrating soil moisture status, plant physiology, and environmental conditions. There are few tools for measuring plant water status (water potential) in situ, presenting a critical barrier for developing appropriate phenotyping (measurement) methods for crop development and modeling efforts aimed at understanding water transport in plants. Here, we present the development of an in situ, minimally disruptive hydrogel nanoreporter (AquaDust) for measuring leaf water potential. The gel matrix responds to changes in water potential in its local environment by swelling; the distance between covalently linked dyes changes with the reconfiguration of the polymer, leading to changes in the emission spectrum via F{\"o}rster Resonance Energy Transfer (FRET). Upon infiltration into leaves, the nanoparticles localize within the apoplastic space in the mesophyll; they do not enter the cytoplasm or the xylem. We characterize the physical basis for AquaDust's response and demonstrate its function in intact maize (Zea mays L.) leaves as a reporter of leaf water potential. We use AquaDust to measure gradients of water potential along intact, actively transpiring leaves as a function of water status; the localized nature of the reporters allows us to define a hydraulic model that distinguishes resistances inside and outside the xylem. We also present field measurements with AquaDust through a full diurnal cycle to confirm the robustness of the technique and of our model. We conclude that AquaDust offers potential opportunities for high-throughput field measurements and spatially resolved studies of water relations within plant tissues.",
keywords = "Nanobiosensors, Plant-water relations, Responsive hydrogel, Water potential",
author = "Piyush Jain and Weizhen Liu and Siyu Zhu and Chang, {Christine Yao Yun} and Jeff Melkonian and Rockwell, {Fulton E.} and Duke Pauli and Ying Sun and Zipfel, {Warren R.} and {Michele Holbrook}, N. and Riha, {Susan Jean} and Gore, {Michael A.} and Stroock, {Abraham D.}",
note = "Funding Information: We thank Glenn Swan and Nicholas S. Kaczmar for technical assistance; Prof. William Philpot for providing ST2000 spectrometer and optical fiber probes; Prof. Jocelyn K. C. Rose and Dr. Iben Sorensen for their technical support for sample preparation for the confocal imaging; Dr. Olivier Vincent for assistance in using vacuum setup; and Jacob L. Wszolek (Cornell Guterman Laboratory) for maintaining the plants in greenhouse and growth chamber. This work was supported by US Department of Agriculture National Institute of Food and Agriculture Agriculture and Food Research Initiative Competitive Grant 2017-67007-25950; and Air Force Office of Scientific Research Grant FA9550-18-1-0345. This work was also supported by Next-Generation BioGreen 21 Program Project PJ01321305, Rural Development Administration, Republic of Korea. This work was performed in part at the Cornell University Biotechnology Resource Center (NIH Grant S10RR025502 for data collected on the Zeiss LSM 710 Confocal and NIH Grant S10OD018516 for data collected on the upright Zeiss LSM880 confocal microscope [u880]) and in part at the Cornell NanoScale Facility, a member of the National Nanotechnology Infrastructure Network (NSF Grant ECCS-1542081). Funding Information: ACKNOWLEDGMENTS. We thank Glenn Swan and Nicholas S. Kaczmar for technical assistance; Prof. William Philpot for providing ST2000 spectrometer and optical fiber probes; Prof. Jocelyn K. C. Rose and Dr. Iben Sorensen for their technical support for sample preparation for the confocal imaging; Dr. Olivier Vincent for assistance in using vacuum setup; and Jacob L. Wszolek (Cornell Guterman Laboratory) for maintaining the plants in green-house and growth chamber. This work was supported by US Department of Agriculture National Institute of Food and Agriculture Agriculture and Food Research Initiative Competitive Grant 2017-67007-25950; and Air Force Office of Scientific Research Grant FA9550-18-1-0345. This work was also supported by Next-Generation BioGreen 21 Program Project PJ01321305, Rural Development Administration, Republic of Korea. This work was performed in part at the Cornell University Biotechnology Resource Center (NIH Grant S10RR025502 for data collected on the Zeiss LSM 710 Confocal and NIH Grant S10OD018516 for data collected on the upright Zeiss LSM880 confocal microscope [u880]) and in part at the Cornell NanoScale Facility, a member of the National Nanotechnology Infrastructure Network (NSF Grant ECCS-1542081). Publisher Copyright: {\textcopyright} 2021 National Academy of Sciences. All rights reserved.",
year = "2021",
month = jun,
day = "8",
doi = "10.1073/pnas.2008276118",
language = "English (US)",
volume = "118",
journal = "Proceedings of the National Academy of Sciences of the United States of America",
issn = "0027-8424",
publisher = "National Academy of Sciences",
number = "23",
}