Stomatal kinetics and photosynthetic gas exchange

 

 

Stomatal kinetics and photosynthetic gas exchange along a continuum of isohydric to anisohydric regulation of plant water status

by Meinzer F. C., Smith D. D., Woodruff D. R., Marias D. E., McCulloh K. A., Howard A. R., Magedman A. L. (2017)

Frederick C. Meinzer 1 , Duncan D. Smith 2 , David R. Woodruff 1 , Danielle E. Marias 3 , Katherine A. McCulloh 3 , Ava R. Howard 4, Alicia L. Magedman 3

1 Pacific Northwest Research Station, USDA Forest Service, Corvallis, OR 97331, USA,

2 Department of Botany, University of Wisconsin, Madison, WI 53706, USA,

3 Department of Forest Ecosystems and Society, Oregon State University, Corvallis, OR 97331, USA and

4 Department of Biology, Western Oregon University, Monmouth, OR 97361, USA

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in Plant, Cell and Environment (2017) 40, 1618–1628 – doi: 10.1111/pce.12970 –

https://www.fs.fed.us/pnw/pubs/journals/pnw_2017_meinzer001.pdf

ABSTRACT

Species’ differences in the stringency of stomatal control of plant water potential represent a continuum of isohydric to anisohydric behaviours. However, little is known about how quasi-steady-state stomatal regulation of water potential may relate to dynamic behaviour of stomata and photosynthetic gas exchange in species operating at different positions along this continuum.

Here, we evaluated kinetics of light-induced stomatal opening, activation of photosynthesis and features of quasi-steady-state photosynthetic gas exchange in 10 woody species selected to represent different degrees of anisohydry. Based on a previously developed proxy for the degree of anisohydry, species’ leaf water potentials at turgor loss, we found consistent trends in photosynthetic gas exchange traits across a spectrum of isohydry to anisohydry.

More anisohydric species had faster kinetics of stomatal opening and activation of photosynthesis, and these kinetics were closely coordinated within species. Quasi-steady-state stomatal conductance and measures of photosynthetic capacity and performance were also greater in more anisohydric species.

Intrinsic water-use efficiency estimated from leaf gas exchange and stable carbon isotope ratios was lowest in the most anisohydric species. In comparisons between gas exchange traits, species rankings were highly consistent, leading to species-independent scaling relationships over the range of isohydry to anisohydry observed.

Coordination between stomatal conductance and leaf-specific hydraulic conductance

 

 

Coordination between stomatal conductance and leaf-specific hydraulic conductance in maize (Zea mays L.)

by Liu L., Kon H., Matsuoka N. Kobayashi T. (2005)

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in J. Agric. Meteorol. 61(3): 143-152 –

https://www.jstage.jst.go.jp/article/agrmet/61/3/61_3_143/_pdf

The effect of atmospheric humidity on stomatal control of gas exchange

 

 

The effect of atmospheric humidity on stomatal control of gas exchange in two tropical coniferous species

by Meinzer F. C., Goldstein G., Jaimes M. (1984)

Frederick C. Meinzer, Guillermo Goldstein, Marisol Jaimes,

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in Canadian Journal of Botany 62(3): 591-595 – https://doi.org/10.1139/b84-089 –

http://www.nrcresearchpress.com/doi/10.1139/b84-089

ABSTRACT

Stomatal response to changes in leaf to air vapor pressure difference (VPD) and its influence on total gas exchange were measured for leaves of Podocarpus oleifolius and Podocarpus rospigliosiiin an open gas exchange system.

Stomatal conductance (g) of both species declined as VPD increased. Once a critical VPD was attained, the decrease in g was sufficient to decrease transpiration rate in spite of increasing VPD. This response pattern suggested “feedforward” control of stomatal response to humidity rather than negative feedback control based on changes in leaf water status. Coupling between CO₂ assimilation and g and inherent water-use efficiency were greater in P. oleifolius.

Stomatal response to humidity in P. oleifolius was consistent with a recent hypothesis that stomata optimize CO₂ assimilation with respect to a given level of water loss by maintaining constant the ratio of the sensitivities of transpiration rate (E) and assimilation rate (A) to changes in g (∂E/∂g/∂A/∂g). This gain ratio did not remain constant in P. rospigliosii as VPD was varied.

The possible ecological basis for these differences in gas exchange behavior is discussed.

The Effect of Light on Stomatal Control of Gas Exchange

 

 

The Effect of Light on Stomatal Control of Gas Exchange in Douglas Fir (Pseudotsuga menziesii) Saplings

by Meinzer F. C. (1982)

Frederick C. Meinzer,

Universidad de los Andes, Merida, Venezuela

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in Oecologia 54(2): 270-274 –

https://www.jstor.org/stable/4216760?seq=1#page_scan_tab_contents

Abstract

Attached twigs of young Pseudotsuga menziesii (Mirb.) Franco plants were subjected to variations in irradiance.

Stomatal responsiveness to irradiance, measured in an open type gas exchange system, varied seasonally. During the autumn and winter, stomatal conductance was relatively unresponsive to changes in irradiance, but during the summer stomatal conductance decreased in response to reduced irradiance. The summer stomatal response to irradiance was such that a nearly constant ratio of stomatal conductance to net photosynthesis was maintained as irradiance was varied. This caused intercellular CO₂ concentration (ci) and water use efficiency (net CO₂ uptake/transpiration) to also remain relatively constant.

At constant irradiance, stomatal conductance was relatively insensitive to experimentally-induced changes in ci. This, and the observation that ci remained relatively constant as irradiance was varied, suggest that changes in ci played a minor role in mediating the stomatal response to light.

The ecological significance of the seasonal changes in stomatal response to light is discussed.

Stomata and Mechanisms for Leaf Control of Gas Exchange

 

 

Mechanisms for Leaf Control of Gas Exchange

by Mansfield T. A., Davies W. J. (1985)

University of lancaster, UK

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in BioScience 35(3): 158-164 – DOI: 10.2307/1309865 –

https://www.jstor.org/stable/1309865?seq=1#page_scan_tab_contents

Abstract

Several mechanisms enable leaf stomata to optimize water loss with respect to carbon gain.

Stomatal responses to environmental variation constitute a plant’s first and second lines of defense against damaging water deficits.

Changes in the concentrations of endogenous growth regulators and their influence on stomata may well be important to both defense strategies.

The relation between stomatal aperture and gas exchange

Figure 1. Schematic depiction and definition of diffusional conductances of water transport between leaf and atmosphere. gL, overall leaf conductance; gs, stomatal conductance; gias, conductance in the inner air spaces between evaporating cell walls and the inner throat of the pore; gc, cuticular conductance; gsi, combined conductance of gias and gs. gsi is introduced, because in contrast to gs it can be calculated from measured gL, gb and gc, when, as usual, gias is not known.

 

The relation between stomatal aperture and gas exchange under consideration of pore geometry and diffusional resistance in the mesophyll

by Kaiser H. (2009)

Hartmut Kaiser,

Botanisches Institut der Christian-Albrechts-Universität zu Kiel, Kiel, Germany

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in Plant, Cell and Environment 32: 1091–1098 – doi: 10.1111/j.1365-3040.2009.01990.x –

https://onlinelibrary.wiley.com/doi/pdf/10.1111/j.1365-3040.2009.01990.x

Figure 3. (a) Three-dimensional reconstruction of a stomatal guard cell pair based on confocal laser scanning microscopy (CLSM) of detached epidermis stained with lipophilic fluorescent stain anilino-naphtalene-sulfonate. (b) Generalized model of a slightly opened stomatal pore of Vicia faba derived from averaged CLSM measurements, which was used for the calculations of stomatal conductance from realistic pore dimensions.

ABSTRACT

The quantitative relation between stomatal aperture and gas exchange through the stomatal pore can be described by physical models derived from Fick’s first law of diffusion. Such models, usually based on a simplified pore geometry, are used to calculate leaf conductance from stomatal pore dimensions or vice versa.

In this study a combination of gas-exchange measurements and simultaneous microscopical observations of stomatal apertures was used to empirically determine this relationship.

The results show a substantial deviation between measured stomatal conductance and that calculated from the simplified models. The main difference is a much steeper increase of conductance with aperture at small apertures.

When the calculation was based on a realistic pore geometry derived from confocal laser scanning microscopy, a good fit to the experimentally found relationship could be obtained if additionally a significant contribution of a mesophyll diffusional resistance was taken into account.

Stomatal conductance increases with rising temperature

 

 

by Urban J., Ingwers M. W., McGuire M. A., Teskey R. O. (2017)

Josef Urban, Department of Forest Botany, Dendrology and Geobiocenology, Mendel University in Brno, Czech Republic; Siberian Federal University, Krasnoyarsk, Russia
,

Miles Ingwers,

Mary Anne McGuire,

Robert O. Teskey,

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in Plant Signal. Behav. 2017, 12, e1356534 – doi: 10.1080/15592324.2017.1356534. Epub 2017 Aug 8. –

[Google Scholar] [CrossRef] [PubMed] –

https://www.ncbi.nlm.nih.gov/pubmed/28786730

Abstract

Stomatal conductance directly modifies plant water relations and photosynthesis. Many environmental factors affecting the stomatal conductance have been intensively studied but temperature has been largely neglected, even though it is one of the fastest changing environmental variables and it is rising due to climate change.

In this study, we describe how stomata open when the temperature increases. Stomatal conductance increased by ca 40% in a broadleaf and a coniferous species, poplar (Populus deltoides x nigra) and loblolly pine (Pinus taeda) when temperature was increased by 10 °C, from 30 °C to 40 °C at a constant vapor pressure deficit of 1 kPa.

The mechanism of regulating stomatal conductance by temperature was, at least partly, independent of other known mechanisms linked to water status and carbon metabolism. Stomatal conductance increased with rising temperature despite the decrease in leaf water potential, increase in transpiration, increase in intercellular CO₂ concentration and was decoupled from photosynthesis.

Increase in xylem and mesophyll hydraulic conductance coming from lower water viscosity may to some degree explain temperature dependent opening of stomata.

The direct stomatal response to temperature allows plants to benefit from increased evaporative cooling during the heat waves and from lower stomatal limitations to photosynthesis but they may be jeopardized by faster depletion of soil water.

The Impact of Heat Stress and Water Deficit on Stomatal Physiology of Olive

 

 

The Impact of Heat Stress and Water Deficit on the Photosynthetic and Stomatal Physiology of Olive (Olea europaea L.)—A Case Study of the 2017 Heat Wave

by Haworth M., Marino G., Brunetti C., Killi D., De Carlo A., Centritto M. (2018)

Matthew Haworth ^1,* ,

Giovanni Marino ¹

,Cecilia Brunetti ^1,2

,Dilek Killi ³

,Anna De Carlo ¹

Mauro Centritto ¹

¹

Tree and Timber Institute, National Research Council of Italy (CNR-IVALSA), Via Madonna del Piano 10, 50019 Firenze, Italy

²

Department of Agrifood Production and Environmental Sciences (DiSPAA), University of Florence, Viale delle Idee 30, 50019 Firenze, Italy

³

Institute of Biometeorology, National Research Council of Italy (CNR-IBIMET), Via Giovanni Caproni 8, 50145 Firenze, Italy

 

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in Plants 7(4): 76 – https://doi.org/10.3390/plants7040076 –

http://www.mdpi.com/2223-7747/7/4/76

Abstract

Heat waves are predicted to increase in frequency and duration in many regions as global temperatures rise. These transient increases in temperature above normal average values will have pronounced impacts upon the photosynthetic and stomatal physiology of plants.

During the summer of 2017, much of the Mediterranean experienced a severe heat wave. Here, we report photosynthetic leaf gas exchange and chlorophyll fluorescence parameters of olive (Olea europaea cv. Leccino) grown under water deficit and full irrigation over the course of the heat wave as midday temperatures rose over 40 °C in Central Italy.

Heat stress induced a decline in the photosynthetic capacity of the olives consistent with reduced ribulose-1,5-bisphosphate carboxylase/oxygenase (RubisCO) activity. Damage to photosystem II was more apparent in plants subject to water deficit. In contrast to previous studies, higher temperatures induced reductions in stomatal conductance.

Heat stress adversely affected the carbon efficiency of olive. The selection of olive varieties with enhanced tolerance to heat stress and/or strategies to mitigate the impact of higher temperatures will become increasingly important in developing sustainable agriculture in the Mediterranean as global temperatures rise.

A Specific Transcriptome Signature for Guard Cells from a C4 Plant

 

 

A Specific Transcriptome Signature for Guard Cells from the C4 Plant Gynandropsis gynandra

by Aubry S., Aresheva O., Reyna-Llorens I., Smith-Unna R. D., Hibberd J. M., Genty B. (2016)

Sylvain Aubry, Olga Aresheva, Ivan Reyna-Llorens, Richard D. Smith-Unna, Julian M. Hibberd, Bernard Genty, 

Aubry S¹, Aresheva O¹, Reyna-Llorens I¹, Smith-Unna RD¹, Hibberd JM², Genty B².

1

Department of Plant Sciences, University of Cambridge, Cambridge CB2 3EA, United Kingdom (S.A., I.R.-L., R.D.S.-U., J.M.H.); andCommissariat à l’Energie Atomique et aux Energies Alternatives, Centre National de la Recherche Scientifique, Unité Mixte de Recherche 7265, and Université Aix-Marseille, Biologie Végétale et Microbiologie Environnementales, 13108 Saint-Paul-lez-Durance, France (O.A., B.G.).

2

Department of Plant Sciences, University of Cambridge, Cambridge CB2 3EA, United Kingdom (S.A., I.R.-L., R.D.S.-U., J.M.H.); andCommissariat à l’Energie Atomique et aux Energies Alternatives, Centre National de la Recherche Scientifique, Unité Mixte de Recherche 7265, and Université Aix-Marseille, Biologie Végétale et Microbiologie Environnementales, 13108 Saint-Paul-lez-Durance, France (O.A., B.G.)

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in Plant Physiol. 170: 1345–1357 – doi: 10.1104/pp.15.01203 –

https://www.ncbi.nlm.nih.gov/pubmed/26818731?dopt=Abstract

Abstract

C4 photosynthesis represents an excellent example of convergent evolution that results in the optimization of both carbon and water usage by plants.

In C4 plants, a carbon-concentrating mechanism divided between bundle sheath and mesophyll cells increases photosynthetic efficiency. Compared with C3 leaves, the carbon-concentrating mechanism of C4 plants allows photosynthetic operation at lower stomatal conductance, and as a consequence, transpiration is reduced.

Here, we characterize transcriptomes from guard cells in C3 Tareneya hassleriana and C4 Gynandropsis gynandra belonging to the Cleomaceae. While approximately 60% of Gene Ontology terms previously associated with guard cells from the C3 model Arabidopsis (Arabidopsis thaliana) are conserved, there is much less overlap between patterns of individual gene expression.

Most ion and CO2 signaling modules appear unchanged at the transcript level in guard cells from C3 and C4 species, but major variations in transcripts associated with carbon-related pathways known to influence stomatal behavior were detected.

Genes associated with C4 photosynthesis were more highly expressed in guard cells of C4 compared with C3 leaves. Furthermore, we detected two major patterns of cell-specific C4 gene expression within the C4 leaf. In the first, genes previously associated with preferential expression in the bundle sheath showed continually decreasing expression from bundle sheath to mesophyll to guard cells. In the second, expression was maximal in the mesophyll compared with both guard cells and bundle sheath.

These data imply that at least two gene regulatory networks act to coordinate gene expression across the bundle sheath, mesophyll, and guard cells in the C4 leaf.

A small peptide modulates stomatal control via ABA

 

 

A small peptide modulates stomatal control via abscisic acid in long-distance signalling

by Takahashi F., Suzuki T., Osakabe Y., Betsuyaku S.,Kondo Y., Dohmae N., Fukuda H., Yamaguchi-Shinozaki K., Shinozaki K. (2018)

• Fuminori Takahashi,
• Takehiro Suzuki,
• Yuriko Osakabe,
• Shigeyuki Betsuyaku,
• Yuki Kondo,
• Naoshi Dohmae,
• Hiroo Fukuda,
• Kazuko Yamaguchi-Shinozaki,
• Kazuo Shinozaki,

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in Nature 556: 235–238 –

https://www.nature.com/articles/s41586-018-0009-2

Abstract

Mammalian peptide hormones propagate extracellular stimuli from sensing tissues to appropriate targets to achieve optimal growth maintenance¹.

In land plants, root-to-shoot signalling is important to prevent water loss by transpiration and to adapt to water-deficient conditions^2, 3. The phytohormone abscisic acid has a role in the regulation of stomatal movement to prevent water loss⁴. However, no mobile signalling molecules have yet been identified that can trigger abscisic acid accumulation in leaves.

Here we show that the CLAVATA3/EMBRYO-SURROUNDING REGION-RELATED 25 (CLE25) peptide transmits water-deficiency signals through vascular tissues in Arabidopsis, and affects abscisic acid biosynthesis and stomatal control of transpiration in association with BARELY ANY MERISTEM (BAM) receptors in leaves.

The CLE25 gene is expressed in vascular tissues and enhanced in roots in response to dehydration stress. The root-derived CLE25 peptide moves from the roots to the leaves, where it induces stomatal closure by modulating abscisic acid accumulation and thereby enhances resistance to dehydration stress.

BAM receptors are required for the CLE25 peptide-induced dehydration stress response in leaves, and the CLE25–BAM module therefore probably functions as one of the signalling molecules for long-distance signalling in the dehydration response.