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Title: Maximizing leaf carbon gain in varying saline conditions: An optimization model with dynamic mesophyll conductance
<bold>SUMMARY</bold> While the adverse effects of elevated salinity levels on leaf gas exchange in many crops are not in dispute, representing such effects on leaf photosynthetic rates (A) continues to draw research attention. Here, an optimization model for stomatal conductance (gc) that maximizesAwhile accounting for mesophyll conductance (gm) was used to interpret new leaf gas exchange measurements collected for five irrigation water salinity levels. A function between chloroplastic CO2concentration (cc) and intercellular CO2concentration (ci) modified by salinity stress to estimategmwas proposed. Results showed that with increased salinity, the estimatedgmand maximum photosynthetic capacity were both reduced, whereas the marginal water use efficiencyλincreased linearly. Adjustments ofgm,λand photosynthetic capacity were shown to be consistent with a large corpus of drought‐stress experiments. The inferred model parameters were then used to evaluate the combined effects of elevated salinity and atmospheric CO2concentration (ca) on leaf gas exchange. For a given salinity level, increasingcaincreasedAlinearly, but these increases were accompanied by mild reductions ingcand transpiration. Thecalevel needed to ameliorateAreductions due to increased salinity is also discussed using the aforementioned model calculations.  more » « less
Award ID(s):
1644382 1754893
PAR ID:
10458846
Author(s) / Creator(s):
 ;  
Publisher / Repository:
Wiley-Blackwell
Date Published:
Journal Name:
The Plant Journal
Volume:
101
Issue:
3
ISSN:
0960-7412
Page Range / eLocation ID:
p. 543-554
Format(s):
Medium: X
Sponsoring Org:
National Science Foundation
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