Stomatal Data of Late Pliocene Betulaceae Leaves

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Figure 3. Examples of hand specimens and cuticles of Betula mioluminifera Hu et Chaney and Carpinus miofangiana Nathorst as used for stomatal and stable carbon isotope analysis. Th e white frames show the sampling sites for cuticular analysis. (a) Fossil leaf of B. mioluminifera, scale bar– 1 cm. (b) Fossil leaf of C. miofangiana, scale bar– 1 cm. (c) Lower epidermis of B. mioluminifera, scale bar– 100 μm. (d) Lower epidermis of C. miofangiana, scale bar- 100 μm.

Carbon Isotope and Stomatal Data of Late Pliocene Betulaceae Leaves from SW China: Implications for Palaeoatmospheric CO2 -levels

by Sun B.-N., Ding S.-T., Wu J.-Y., Dong C., Xie S., Lin Z.-C. ( 2012)


1 Lanzhou University, College of Earth and Environmental Sciences, Key Laboratory of Western China’s Environmental Systems of the Ministry of Education, Lanzhou 730000, China; State Key Laboratory of Palaeobiology and Stratigraphy, Nanjing Institute of Geology and Palaeontology, CAS, Nanjing 210008, China

2 Lanzhou University, College of Earth and Environmental Sciences, Lanzhou 730000, China; State Key Laboratory of Palaeobiology and Stratigraphy, Nanjing Institute of Geology and Palaeontology, CAS, Nanjing 210008, China

3 Lanzhou University, College of Earth and Environmental Sciences, Lanzhou 730000, China


in Turkish Journal of Earth Sciences (Turkish J. Earth Sci.), 21: 237–250 – doi:10.3906/yer-1003-42 –


The cuticular δ13C values and stomatal parameters (stomatal density and stomatal index: SD and SI) of two Betulaceae species, Betula mioluminifera Hu et Chaney and Carpinus miofangiana Nathorst, from a suite of superposed horizons in West Yunnan, southwestern China, were measured in order to recover Late Pliocene CO2 levels.

Correlations are given for δ13C, SD, epidermal cell density (ECD), and SI. δ13C reveals a positive trend with the SD and SI in the two species, and such a positive correlation can also be observed between the δ13C and ECD in C. miofangiana. However, δ13C has a slightly negative correlation with the ECD in B. mioluminifera (R2 = 0.06), possibly influenced by their different genotypes.

Reflecting the changes through time, the δ13C values of B. mioluminifera and C. miofangiana significantly increase with high determination coefficients (R2 = 0.67 and R2 = 0.65, respectively), as do SD (R2 = 0.66 and R2 = 0.51, respectively) and SI (R2 = 0.50 and R2 = 0.79, respectively).

Research on extant B. luminifera and C. fangiana shows that the SD and especially SI, exhibit a prominent negative correlation with CO2 concentration. Pliocene CO2 levels are reconstructed as 381.5–439.4 ppmv and 377.8–472.3 ppmv, respectively, based on comparisons of the two fossil species with their nearest living equivalent (NLE) species.

The significant positive trends of the δ13C, SD and SI with ascending position of the fossils in the section indicate that the atmospheric CO2 levels declined in the Late Pliocene (3.30–2.83 Ma). Furthermore, the calculated CO2 levels are higher than in other studies and probably demonstrate that local CO2 enrichment can be caused by frequent volcanic eruptions over a long time scale.


Physiologically active stomatal control originated at least as far back as the emergence of the lycophytes

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Figure 4. Stomatal Response Mechanisms Are Conserved between a Basal Vascular Plant and Flowering Plants (A) Treatment with the Ca2+ chelator EGTA (+EGTA, 10 mM) or the Ca2+ channel blocker verapamil (+Ver, 25 μM) partially inhibits ABA-induced reductions in S. uncinata stomatal aperture. Gray bars show controls, white bars show 25 μM ABA. Data are mean values ± SEM of three independent experiments (n = 120). Stomata are significantly more closed with ABA alone than in combination with EGTA or verapamil (p < 0.005; Student’s t test). (B) Following ABA treatment (white bar, 25 μM ABA), reactive oxygen species (ROS) levels in S. uncinata stomata increase significantly compared to controls (gray bar, −ABA) (p < 0.005; Student’s t test) as detected by fluorescence intensity of H2DCF-DA. Data shown are mean fluorescence intensity ± SEM of three independent experiments (n = 150). (C and D) Accumulation of vacuolar K+ deposits in guard cells of S. uncinata incubated in light (C) or dark (D) conditions. White arrows highlight sodium potassium cobaltinitrite deposit (n = 3). (E) 10 μM fusicoccin (FC, hatched bar) promotes significant stomatal opening in preclosed stomata of S. uncinata compared to control (black bar) (p < 0.005; Student’s t test). Data shown are mean values ± SEM from three independent experiments (n = 100). (F) ABA-induced promotion of stomatal closure in Arabidopsis thaliana lines wild-type (WT; Col-2), ost1-4, and three T2 independent transgenic lines (#1–#3) expressing SmOST1 in the ost1-4 background (ost1-4;AtOST1PRO::SmOST1). Transgenic lines are indicated by brackets. Data are mean values ± SEM (n = 90) for peels incubated with 1 μM ABA (light gray bars) and 10 μM ABA (white bars) or controls (dark gray bars); ABA induces significant closure in the WT line and transgenic lines #1, #2, and #3 (p < 0.001; Student’s t test). ABA and control treatments do not differ significantly in ost1-4 (p = 0.125; Student’s t test). (G) Detection of the SmOST1 transgene in complemented lines #1, #2, and #3 by RT-PCR. Actin was amplified as a control. Transgenic lines expressing SmOST1 in the ost1-4 background (ost1-4;AtOST1PRO::SmOST1) are indicated by the bracket.


Land plants acquired active stomatal control early in their evolutionary history

by Ruszala E. M., Beerling D. J., Franks P. J., Chater C., Casson S. A., Gray J. E., Hetherington A. M. (2011)

Elizabeth M.Ruszala, David J.Beerling, Peter J.Franks, 2CasparChater, Stuart A.Casson, Julie E.Gray, Alistair M.Hetherington, 1

School of Biological Sciences, University of Bristol, Bristol BS8 1UG, UK
Department of Animal and Plant Sciences, University of Sheffield, Sheffield S10 2TN, UK
Department of Molecular Biology and Biotechnology, University of Sheffield, Sheffield S10 2TN, UK
Faculty of Agriculture, Food & Natural Resources, The University of Sydney, Sydney, NSW 2006, Australia


in Curr Biol 21(12): 1030–1035 – –


Stomata are pores that regulate plant gas exchange [1]. They evolved more than 400 million years ago [23], but the origin of their active physiological responses to endogenous and environmental cues is unclear [23456]. Recent research suggests that the stomata of lycophytes and ferns lack pore closure responses to abscisic acid (ABA) and CO2. This evidence led to the hypothesis that a fundamental transition from passive to active control of plant water balance occurred after the divergence of ferns 360 million years ago [78]. Here we show that stomatal responses of the lycophyte Selaginella [9] to ABA and CO2 are directly comparable to those of the flowering plant Arabidopsis [10]. Furthermore, we show that the underlying intracellular signaling pathways responsible for stomatal aperture control are similar in both basal and modern vascular plant lineages. Our evidence challenges the hypothesis that acquisition of active stomatal control of plant carbon and water balance represents a critical turning point in land plant evolution [78]. Instead, we suggest that the critical evolutionary development is represented by the innovation of stomata themselves and that physiologically active stomatal control originated at least as far back as the emergence of the lycophytes (circa 420 million years ago) [11].


► Active stomatal responses to CO2 and ABA are evolutionarily ancient

► Active stomatal responses to CO2 and ABA are present in Selaginella

► Stomata are a key evolutionary innovation vital to the success of the land plants

Highresolution stomatal index data show that atmospheric CO2 may have played an important role in climate dynamics during the last deglaciation



Late-glacial and early Holocene variations in atmospheric CO2 concentration indicated by highresolution stomatal index data

by Rundgren M., Björck S. (2003)

Mats Rundgren , Svante Björck,

Department of Geology, Quaternary Sciences, Lund University, So«lvegatan 12, SE-223 62 Lund, Sweden


in Earth Planet. Sc. Lett. 213: 191–204 –


Data from ice cores suggest that Late-glacial and early Holocene atmospheric CO2 variations were rather conservative, the most important change being a gradual Younger Dryas increase. By contrast, palaeo-CO2records based on the inverse relationship between CO2 partial pressure and stomatal frequency of terrestrial plant leaves reflect a more dynamic CO2evolution, including an abrupt decrease at the Allerød/Younger Dryas transition.

Here we present a Late-glacial and early Holocene CO2 record based on stomatal index data from leaves preserved in the sediments of a small lake in southwestern Sweden. Three independent records constructed from stomatal index data of Salix polarisSalix herbacea and Betula nanaleaves were combined to form a high-resolution CO2 reconstruction for the period 12 800–10 800 cal yr BP.

Atmospheric CO2 concentrations were found to have decreased rapidly from c. 260 ppmv to 210–215 ppmv within 200 years during the Allerød (GI-1)/Younger Dryas (GS-1) transition. After 100–200 years, CO2 concentration started to gradually increase to 270–290 ppmv at the end of the Younger Dryas stadial (GS-1). CO2 concentrations were relatively stable during the early Holocene, except for a short-lived period of lower (240–250 ppmv) values c. 11 350–11 200 cal yr BP. This Late-glacial and early Holocene CO2 evolution partly resembles previous stomatal-based CO2 reconstructions, and the overall trend is almost identical to that seen in ice-core records.

The amplitude of change is, however, markedly higher in the Swedish stomatal-based record compared to the ice cores. This difference may partly be accounted for by the inherent smoothing of ice-core CO2 records caused by diffusion, but a major part of the difference in amplitude between ice-core and stomatal-based records still remains to be explained.

Based on our reconstruction, atmospheric CO2 may have played an important role in climate dynamics during the last deglaciation.

A CO2 reconstruction based on stomatal distributions in fossil and extant Ginkgo and Metasequoia cuticles



Estimating latest Cretaceous and Tertiary atmospheric CO2 from stomatal indices

by Royer D. L. (2003)

Dana L. Royer,

Department of Geology and Geophysics, Yale University, P.O. Box 208109, New Haven, Connecticut 06520-8109, USA.


in Wing, S.L., Gingerich, P.D., Schmitz, B., and Thomas, E., eds., Causes and Consequences of Globally Warm Climates in the Early Paleogene: Boulder, Colorado, Geological Society of America Special Paper 369: 79–93 –

doi:10.1130/0-8137-2369-8.79 –


A quantitative understanding of the levels of atmospheric CO2 in the geologic past sheds light on the operation of the carbon cycle and the biosphere, and aids in the prediction of future climate change.

Here I present a CO2 reconstruction for the very latest Cretaceous to early Eocene and middle Miocene based on the stomatal distributions in fossil and extant Ginkgo and Metasequoia cuticles.

Although both of these intervals are representative of globally warm climates, my CO2 reconstruction indicates near present-day values (300–450 ppmV) for both times. Although these data do not cast doubt on the theory of the greenhouse effect, they do suggest that other thermal forcings were more important during these intervals than they are today


Stomatal pore length change from the Late Eocene to the Latest Oligocene



Stomatal pore length change in leaves of Eotrigonolanalus furcinervis (Fagaceae) from the Late Eocene to the Latest Oligocene and its impact on gas exchange

by Roth-Nebelsick A., Grein M., Utescher T., Konrad W. (2012)

Anita Roth-NebelsickMichaela GreinTorsten UtescherWilfried Konrad,


in Rev. Palaeobot. Palynol. 174: 106–112 – DOI: 10.1016/j.revpalbo.2012.01.001 –


Stomata and models to develop a multi-scale assessment of the impact of changing c(a) on CO2 uptake and water use



Sensitivity of plants to changing atmospheric CO2concentration: from the geological past to the next century

by Franks P. J., Adams M. A., Amthor J. S., Barbour M. M., Berry J. A., Ellsworth D. S., Farquhar G. D., Ghannoum O., Lloyd J., McDowell N., Norby R. J., Tissue D. T., von Caemmerer S. (2013)


Faculty of Agriculture and Environment, University of Sydney, Sydney, NSW, Australia


in New Phytol. 197(4): 1077-1094 – – 

CrossRefPubMedWeb of ScienceGoogle Scholar


The rate of CO(2) assimilation by plants is directly influenced by the concentration of CO(2) in the atmosphere, c(a). As an environmental variable, c(a) also has a unique global and historic significance. Although relatively stable and uniform in the short term, global c(a) has varied substantially on the timescale of thousands to millions of years, and currently is increasing at seemingly an unprecedented rate. This may exert profound impacts on both climate and plant function.

Here we utilise extensive datasets and models to develop an integrated, multi-scale assessment of the impact of changing c(a) on plant carbon dioxide uptake and water use.

We find that, overall, the sensitivity of plants to rising or falling c(a) is qualitatively similar across all scales considered. It is characterised by an adaptive feedback response that tends to maintain 1 – c(i)/c(a), the relative gradient for CO(2) diffusion into the leaf, relatively constant.

This is achieved through predictable adjustments to stomatal anatomy and chloroplast biochemistry. Importantly, the long-term response to changing c(a) can be described by simple equations rooted in the formulation of more commonly studied short-term responses.

Stomatal density record of fossil leaves spanning the past 400 Myr supporting the predicted changes in atsmopheric CO2



Changes in land plant function over the Phanerozoic: Reconstructions based on the fossil record

by Beerling D. J.Woodward I. (1997)

David J. Beerling, The University of Sheffield (Sheffield, United Kingdom)

Ian Woodward, The University of Sheffield (Sheffield, United Kingdom)


in Botanical Journal of the Linnean Society 124(2):137 – 153 –

CrossRefWeb of ScienceGoogle Scholar


Major fluctuations in the concentrations of atmospheric CO2and O2are predicted by historical long-term carbon and oxygen cycle models of atmospheric evolution and will have impacted directly on past climates, plant function and evolutionary processes.

Here, palaeobotanical evidence is presented from the stomatal density record of fossil leaves spanning the past 400 Myr supporting the predicted changes in atsmopheric CO2.

Evidence from experiments on plants exposed to long-term high CO2environments and the newly assembled fossil data indicate the potential for genetic modification of stomatal characters. The influence of the changes in fossil stomatal characteristics and atmospheric composition on the rates of leaf gas exchange over the course of land plant evolution has been investigated through modelling. Three contrasting eras of plant water economies emerge in the Devonian (high), Carboniferous (low) and from the Upper Jurassic to the present-day (high but declining).

These patterns of change result from structural changes of the leaves and the impact of atmospheric CO2and O2concentrations on RuBisCo function and are consistent with the fossil evidence of sequential appearances of novel plant anatomical changes.

The modelling approach is tested by comparing predicted leaf stable carbon isotope ratios with those measured on fossil plant and organic material. Viewed in a geological context, current and future increases in the concentration of atmospheric CO2might be considered as restoring plant function to that more typically experienced by plants over the majority of their evolutionary history.