The ratio of plant carbon gain to water use, known as water use efficiency (WUE), has long been recognized as a key constraint on crop production and an important target for crop improvement. WUE is a physiologically and genetically complex trait that can be defined at a range of scales. Many component traits directly influence WUE, including photosynthesis, stomatal and mesophyll conductances, and canopy structure. Interactions of carbon and water relations with diverse aspects of the environment and crop development also modulate WUE. As a consequence, enhancing WUE by breeding or biotechnology has proven challenging but not impossible. This review aims to synthesize new knowledge of WUE arising from advances in phenotyping, modeling, physiology, genetics, and molecular biology in the context of classical theoretical principles. In addition, we discuss how rising atmospheric CO 2 concentration has created and will continue to create opportunities for enhancing WUE by modifying the trade-off between photosynthesis and transpiration.
|Original language||English (US)|
|Number of pages||28|
|Journal||Annual Review of Plant Biology|
|State||Published - Apr 2019|
Bibliographical noteFunding Information:
The modeling work conducted by A.W. and G.L.H. is supported by the Australian Research Council Centre of Excellence for Translational Photosynthesis (CE1401000015) and funded by the Australian government. The work of A.D.B.L., J.N.F., and C.P.P. was supported by award numbers DE-SC0008769, DE-AR0000661, and DE-SC0018277 from the US Department of Energy and grant number PGR-1238030 from the Directorate of Biological Sciences of the National Science Foundation. We thank Margaret Barbour, Elizabete Carmo-Silva, Christine Edwards, Phillip Jackson, Thomas Juenger, Mohankumar Kapanigowda, and Xinguang Zhu for sharing photosynthetic gas exchange data. We thank Annual Reviews staff for assistance with graphic design and copyediting.
- drought tolerance