Stable Isotope Composition of Stem and Leaf Water: Applications to the Study of Plant Water Use

1991 ◽  
Vol 5 (2) ◽  
pp. 270 ◽  
Author(s):  
L. B. Flanagan ◽  
J. R. Ehleringer
Keyword(s):  
Stable Isotope ◽  
Water Use ◽  
Isotope Composition ◽  
Leaf Water ◽  
Plant Water ◽  
Stable Isotope Composition ◽  
Plant Water Use

scholarly journals The importance of cuticular permeance in assessing plant water–use strategies

2020 ◽  
Vol 40 (4) ◽  
pp. 425-432
Author(s):  
Matthew Lanning ◽  
Lixin Wang ◽  
Kimberly A Novick
Keyword(s):  
Water Stress ◽  
Water Potential ◽  
Water Use ◽  
Leaf Water Potential ◽  
Stress Responses ◽  
Leaf Water ◽  
Plant Water ◽  
Stomatal Control ◽  
Plant Water Use ◽  
The Impact

Abstract Accurate understanding of plant responses to water stress is increasingly important for quantification of ecosystem carbon and water cycling under future climates. Plant water-use strategies can be characterized across a spectrum of water stress responses, from tight stomatal control (isohydric) to distinctly less stomatal control (anisohydric). A recent and popular classification method of plant water-use strategies utilizes the regression slope of predawn and midday leaf water potentials, σ, to reflect the coupling of soil water availability (predawn leaf water potential) and stomatal dynamics (daily decline in leaf water potential). This type of classification is important in predicting ecosystem drought response and resiliency. However, it fails to explain the relative stomatal responses to drought of Acer sacharrum and Quercus alba, improperly ranking them on the spectrum of isohydricity. We argue this inconsistency may be in part due to the cuticular conductance of different species. We used empirical and modeling evidence to show that plants with more permeable cuticles are more often classified as anisohydric; the σ values of those species were very well correlated with measured cuticular permeance. Furthermore, we found that midday leaf water potential in species with more permeable cuticles would continue to decrease as soils become drier, but not in those with less permeable cuticles. We devised a diagnostic parameter, Γ, to identify circumstances where the impact of cuticular conductance could cause species misclassification. The results suggest that cuticular conductance needs to be considered to better understand plant water-use strategies and to accurately predict forest responses to water stress under future climate scenarios.

The dominant environmental driver of leaf water stable isotope enrichment differs for H-2 compared to O-18

2020 ◽  
Author(s):  
Matthias Cuntz ◽  
Lucas A Cernusak ◽  
Keyword(s):  
Stable Isotope ◽  
Relative Humidity ◽  
Air Temperature ◽  
Gordon Equation ◽  
Isotope Composition ◽  
Environmental Variable ◽  
Leaf Water ◽  
Source Water ◽  
Stable Isotope Composition ◽  
Water Stable Isotope

<p>Several important isotopic biomarkers derive at least part of their signal from the stable isotope composition of leaf water (e.g., leaf wax δ<sup>2</sup>H, cellulose δ<sup>2</sup>H and δ<sup>18</sup>O, lignin δ<sup>18</sup>O). In order to interpret these isotopic proxies, it is therefore helpful to know which environmental variable most strongly controls a given leaf water stable isotope signal. We collated observations of the stable isotope compositions of leaf water, xylem water, and atmospheric vapour, along with air temperature and relative humidity, to test whether the dominant driver of leaf water <sup>2</sup>H concentration could differ from that of <sup>18</sup>O concentration. Our dataset comprises 690 observations from 35 sites with broad geographical coverage. We limited our analysis to daytime observations, when the photosynthetic processes that incorporate the leaf water isotopic signal primarily take place. The Craig-Gordon equation was generally a good predictor for daytime bulk leaf water stable isotope composition for both δ<sup>2</sup>H (R<sup>2</sup>=0.86, p<0.001) and δ<sup>18</sup>O (R<sup>2</sup>=0.63, p<0.001). It showed about 10% admixture of source water was caused by unenriched water pools such as leaf veins or the Péclet effect. Solving the Craig-Gordon equation requires knowledge of relative humidity, air temperature, and the stable isotope compositions of source water and atmospheric vapour. However, it is not possible to invert the Craig-Gordon equation to solve for one of these parameters unless the others are known. Here we show that the two isotopic signals of δ<sup>2</sup>H and δ<sup>18</sup>O are predominantly driven by different environmental variables: leaf water δ<sup>2</sup>H correlated most strongly with the δ<sup>2</sup>H of source water (R<sup>2</sup>=0.68, p<0.001) and atmospheric vapour (R<sup>2</sup>=0.63, p<0.001), whereas leaf water δ<sup>18</sup>O correlated most strongly with air relative humidity (R<sup>2</sup>=0.46, p<0.001). We conclude that these two isotopic signals of leaf water are not simply mirror images of the same environmental information, but carry distinct signals of different climate factors, with crucial implications for the interpretation of downstream isotopic biomarkers.</p>

scholarly journals A genetic link between whole-plant water use efficiency and leaf carbon isotope composition in the C4 grass Setaria

2018 ◽  
Author(s):  
Patrick Z. Ellsworth ◽  
Max J. Feldman ◽  
Ivan Baxter ◽  
Asaph B. Cousins
Keyword(s):  
Plant Breeding ◽  
Water Use Efficiency ◽  
Water Use ◽  
Genetic Architecture ◽  
Isotope Composition ◽  
Plant Water ◽  
Breeding Programs ◽  
Plant Water Use ◽  
Whole Plant ◽  
Use Efficiency

AbstractIncreasing whole plant water use efficiency (yield per transpiration; WUEplant) through plant breeding can benefit the sustainability of agriculture and improve crop yield under drought. To select for WUEplant, an efficient phenotyping method that reports on the genetic contribution of component traits such as transpiration efficiency (TEi; rate of CO2 assimilation per stomatal conductance) must be developed. Leaf carbon stable isotope composition (δ13Cleaf) has been proposed as a high-throughput proxy for TEi, and a negative correlation between δ13Cleaf and both WUEplant and TEi has previously been demonstrated in several C4 grass species. Therefore, the aim of the research presented here was to determine if the same loci control δ13Cleaf, WUEplant, and TEi under well-watered and water-limited conditions in a recombinant inbred line (RIL) population of closely related C4 grasses Setaria viridis and S. italica. Three quantitative trait loci (QTL) for δ13Cleaf were co-localized with transpiration, biomass, and a linear model of WUE. When WUEplant was calculated for allele classes based on the three QTL for δ13Cleaf, δ13Cleaf was negatively correlated with WUEplant as theory predicts when WUEplant is in part driven by differences in TEi. In any population, multiple traits can influence WUEplant; however, the analysis of δ13Cleaf in this RIL population demonstrates that there is genetic control of TEi that significantly contributes to WUEplant. Furthermore, this research suggests that δ13Cleaf can be used in marker-assisted breeding to select for TEi and as a tool to better understand the physiology and genetic architecture of TEi and WUEplant in C4 species.Significance StatementOverextended water resources and drought are major agricultural problems worldwide. Therefore, selection for increased plant water use efficiency (WUEplant) in food and biofuel crop species is an important trait in plant breeding programs. Leaf carbon isotopic composition (δ13Cleaf) has potential as a rapid and effective high throughput phenotyping method for intrinsic transpiration efficiency (TEi), an important leaf-level component trait of WUEplant. Our research shows that δ13Cleaf and WUEplant share a common genetic architecture through their shared relationship with TEi. This suggests that δ13Cleaf can be used as a screen for TEi in marker-assisted plant breeding programs to improve crop drought resistance and decrease agricultural water consumption.

Advances in the study of stable isotope composition of leaf water in plants

2013 ◽  
Vol 33 (4) ◽  
pp. 1031-1041 ◽  
Author(s):  
罗伦 LUO Lun ◽  
余武生 YU Wusheng ◽  
万诗敏 WAN Shimin ◽  
周平 ZHOU Ping
Keyword(s):  
Stable Isotope ◽  
Isotope Composition ◽  
Leaf Water ◽  
Stable Isotope Composition
Sign in / Sign up

Export Citation Format

Share Document