Gravimetric phenotyping of whole plant transpiration responses to atmospheric vapour pressure deficit identifies genotypic variation in water use efficiency

Abstract Genotypes in crop species have been identified that initiate partial stomata closure at elevated atmospheric vapor pressure deficit (VPD), which results in conserved soil water for crop use during subsequent water‐deficit episodes and thereby allowing for possible yield increase. In sweet corn ( Zea mays L), 17 genotypes have been previously identified with the VPD‐responsive trait, although the VPD value at the initiation of stomata closure varied among genotypes. A hypothesis to explain variation in transpiration response to VPD is that water flow capacity in the leaves differs among genotypes. To gauge water flow capacity in leaves, the rate of stomata opening was observed visually after stomata closure was induced by 3 kPa VPD. The stomata opening time was rapid and varied among genotypes from 90 to 179 s. However, there was no correlation between opening time and the VPD at which partial stomata closure was initiated in intact plants. An additional set of experiments was done to examine whether genotypic differences in a subpopulation of silver‐inhibited aquaporins might contribute to differences in leaf water flow. There was a correlation among genotypes between slow opening time of the stomata and greater inhibition of transpiration rate following feeding leaves with silver ion. However, the response to the silver treatment did not correlate with the VPD at which transpiration decrease of intact plants was initiated. These results indicate that the differences observed in the water flow capacity in sweet corn leaves were not major factors accounting for the genotypic differences in whole‐plant transpiration response to elevated VPD.

10.1002/csc2.20711

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Citations (4)

Transpiration responses to vapor pressure deficit in well watered ‘slow-wilting’ and commercial soybean

Environmental and Experimental Botany (2007)

Andrew Fletcher Thomas R. Sinclair L. H. Allen

Wilting

Water Use Efficiency

Growing season

10.1016/j.envexpbot.2007.05.004

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Citations (329)

Temperature influences the ability of tall fescue to control transpiration in response to atmospheric vapour pressure deficit

Functional Plant Biology (2012)

Shannon M. Sermons Thomas M. Seversike Thomas R. Sinclair Edwin L. Fiscus Thomas W. Rufty

Water availability for turfgrass systems is often limited and is likely to become more so in the future. Here, we conducted experiments that examined the ability of tall fescue (Festuca arundinacea Schreb.) to control transpiration with increasing vapour pressure deficit (VPD) and determined whether control was influenced by temperature. The first study was under steady-state conditions at two temperatures (21 and 27°C) and two VPDs (1.2 and 1.8 kPa). At the lower temperature, water use was similar at both VPDs, indicating a restriction of transpiration at high VPD. At 27°C, transpiration control at high VPD was weakened and root growth also declined; both responses increase susceptibility to water-deficit stress. Another series of experiments was used to examine the physiological stability of the transpiration control. Temperature and VPD were adjusted in a stepwise manner and transpiration measured across a range of VPD in the days following environmental shifts. Results indicated that VPD control acclimated to the growth environment, with adjustment to drier conditions becoming evident after ~1 week. Control was again more effective at cool than at hot temperatures. Collectively, the results indicate that transpiration control by this cool season grass is most effective in the temperature range where it is best adapted.

Festuca arundinacea

10.1071/fp12172

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Citations (32)

Limited-Transpiration Rate Under Elevated Atmospheric Vapor Pressure Deficit

SpringerBriefs in environmental science (2017)

Thomas R. Sinclair

10.1007/978-3-319-56321-3_3

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Citations (4)

Temperature effect on transpiration response of maize plants to vapour pressure deficit

Environmental and Experimental Botany (2012)