Optimization theory explains nighttime stomatal responses
Abstract
Nocturnal transpiration is widely observed across species and biomes, and may significantly impact global water, carbon, and energy budgets. However, it remains elusive why plants lose water at night and how to model it at large scales. We hypothesized that plants optimize nighttime leaf diffusive conductance (g_(wn)) to balance potential daytime photosynthetic benefits and nocturnal transpiration benefits. We quantified nighttime benefits from respiratory reductions due to evaporative leaf cooling. We described nighttime costs in terms of a reduced carbon gain during the day because of water use at night. We measured nighttime stomatal responses and tested our model with water birch (Betula occidentalis) saplings grown in a glasshouse. The g_(wn) of water birch decreased with drier soil, higher atmospheric CO₂, wetter air, lower leaf temperature, and lower leaf respiration rate. Our model predicted all these responses correctly, except for the response of g_(wn) to air humidity. Our results also suggested that the slow decrease in g_(wn) after sunset could be associated with decreasing leaf respiration. The optimality‐based nocturnal transpiration model smoothly integrates with daytime stomatal optimization approaches, and thus has the potential to quantitatively predict nocturnal transpiration across space and time.
Additional Information
© 2021 The Authors. New Phytologist © 2021 New Phytologist Foundation. Issue Online: 15 April 2021; Version of Record online: 24 March 2021; Accepted manuscript online: 12 February 2021; Manuscript accepted: 02 February 2021; Manuscript received: 22 October 2020. Research Funding: David and Lucille Packard Foundation; NSF. Grant Numbers: 1714972, 1802880, 2003205, 2003205; USDA National Institute of Food and Agriculture, Agricultural and Food Research Initiative Competitive Programme. Grant Number: 2018‐67012‐31496; Ecosystem Services and Agro‐ecosystem Management. Grant Number: 2018‐67019‐27850; University of California Laboratory Fees Research Program. Grant Number: LFR‐20‐652467.Attached Files
Supplemental Material - nph17267-sup-0001-supinfo.pdf
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Additional details
- Eprint ID
- 108048
- DOI
- 10.1111/nph.17267
- Resolver ID
- CaltechAUTHORS:20210212-133817842
- David and Lucille Packard Foundation
- DEB-1714972
- NSF
- DEB-1802880
- NSF
- 2003205
- NSF
- 2018‐67012‐31496
- United States Department of Agriculture (USDA)
- 2018‐67019‐27850
- United States Department of Agriculture (USDA)
- LFR‐20‐652467
- University of California
- Created
-
2021-02-12Created from EPrint's datestamp field
- Updated
-
2023-10-02Created from EPrint's last_modified field
- Caltech groups
- Division of Geological and Planetary Sciences