Stomatal response to a heavy snowfall

Adaptation of stomatal response of Camellia rusticana to a heavy snowfall environment: Winter drought and net photosynthesis

Kume A., Tanaka C. (1996)

Atsushi Kume, Chikako Tanaka,

Department of Biology, School of Education, Waseda University, Tokyo, Japan


In Ecological Research 11: 207-216 –


The adaptation of Camellia rusticana, an evergreen broad-leaved shrub found in areas of heavy snowfall in Japan, to heavy snowfall environments, and the mechanisms by which it is damaged in winter above the snow, were investigated.

The stomatal response and photosynthetic characteristics of C. rusticana were compared to those of Camellia japonica found in areas of light snowfall. In field conditions, the mean net photosynthesis of C. rusticana at photon flux density (PFD) over 200 μmol m−2s−1 (Pn(>200). was 50% larger than that of C. japonica, but in both light saturated and CO2 saturated conditions, the O2 evolution rate (Pc) of C. rusticana was not different from that of C. japonica.

Mean leaf conductance at PFD over 200 μmol m−2s−1 (gl(>200)) was about 100% larger than that of C. japonica in the field. The Pn(>200)) was 50% ratio of C. rusticana was 37% higher than that of C. japonica which suggests that C. rusticana‘s larger Pn(>200) can be explained by its larger gl(>200).

When C. rusticana trees wintering underneath the snow were projected above it, the leaves of these plants showed serious drought within five days in non-freezing conditions. Their Pc and the maximum stomatal conductance decreased by half and did not recover.

The leaves of C. rusticana showed larger gl(>200) and a less sensitive stomatal response to the decrease of leaf water potential than that of C. japonica.

The stomata characteristics of C. rusticana caused larger net photosynthesis than that of C. japonica during the no snow period, and caused the need for snow cover in winter as protector from winter drought.


Hydraulic theory predicts stomatal responses to climatic water deficits

Pragmatic hydraulic theory predicts stomatal responses to climatic water deficits

by Sperry J. S., Wang Y., Wolfe B. T., Mackay D. S., Anderegg W. R. L., McDowell N. G., Pockman W. T. (2016)

John Sperry, Yujie Wang, Brett Wolfe, D. Scott Mackay, William R L Anderegg, Nate McDowell, William Pockman,

Sperry JS1Wang Y2Wolfe BT3Mackay DS4Anderegg WR2McDowell NG5Pockman WT6.

1 Department of Biology, University of Utah, Salt Lake City, UT, 84112, USA.

2 Department of Biology, University of Utah, Salt Lake City, UT, 84112, USA.

3 Smithsonian Tropical Research Institute, PO Box 0843-03092, Balboa, Panama.

4 Department of Geography, State University of New York, Buffalo, NY, 14260, USA.

5 Earth and Environmental Sciences Division, Los Alamos National Lab, Los Alamos, NM, 87545, USA.

6 Biology Department, University of New Mexico, Albuquerque, NM, 87131, USA.


In New Phytol. 212: 577–589 – DOI: 10.1111/nph.14059


Ecosystem models have difficulty predicting plant drought responses, partially from uncertainty in the stomatal response to water deficits in soil and atmosphere.

We evaluate a ‘supply-demand’ theory for water-limited stomatal behavior that avoids the typical scaffold of empirical response functions. The premise is that canopy water demand is regulated in proportion to threat to supply posed by xylem cavitation and soil drying.

The theory was implemented in a trait-based soil-plant-atmosphere model. The model predicted canopy transpiration (E), canopy diffusive conductance (G), and canopy xylem pressure (Pcanopy ) from soil water potential (Psoil ) and vapor pressure deficit (D). Modeled responses to D and Psoil were consistent with empirical response functions, but controlling parameters were hydraulic traits rather than coefficients.

Maximum hydraulic and diffusive conductances and vulnerability to loss in hydraulic conductance dictated stomatal sensitivity and hence the iso- to anisohydric spectrum of regulation. The model matched wide fluctuations in G and Pcanopy across nine data sets from seasonally dry tropical forest and piñon-juniper woodland with < 26% mean error.

Promising initial performance suggests the theory could be useful in improving ecosystem models. Better understanding of the variation in hydraulic properties along the root-stem-leaf continuum will simplify parameterization

The stomatal response to rising CO2 concentration and drought

The stomatal response to rising CO2 concentration and drought is predicted by a hydraulic trait-based optimization model

by Wang Y., Sperry J. S., Venturas M. D., Trugman A. T., Love D. M., Anderegg W. R. L. (2019)

Yujie Wang 1, John S. Sperry1, Martin D. Venturas 1, Anna T. Trugman 1, David M. Love 1,2 and William R. L. Anderegg 1

1 School of Biological Sciences, University of Utah, Salt Lake City, 257S 1400E, UT 84112, USA;

2 Warnell School of Forestry and Natural Resources, University of Georgia, 180 E Green Street, Athens, GA 30602-2152, USA


In Tree Physiology 00: 1-12 –


Modeling stomatal control is critical for predicting forest responses to the changing environment and hence the global
water and carbon cycles. A trait-based stomatal control model that optimizes carbon gain while avoiding hydraulic
risk has been shown to perform well in response to drought. However, the model’s performance against changes in
atmospheric CO2, which is rising rapidly due to human emissions, has yet to be evaluated. The present study tested
the gain–risk model’s ability to predict the stomatal response to CO2 concentration with potted water birch (Betula
occidentalis Hook.) saplings in a growth chamber. The model’s performance in predicting stomatal response to changes
in atmospheric relative humidity and soil moisture was also assessed. The gain–risk model predicted the photosynthetic
assimilation, transpiration rate and leaf xylem pressure under different CO2 concentrations, having a mean absolute
percentage error (MAPE) of 25%. The model also predicted the responses to relative humidity and soil drought with
a MAPE of 21.9% and 41.9%, respectively. Overall, the gain–risk model had an MAPE of 26.8% compared with the
37.5% MAPE obtained by a standard empirical model of stomatal conductance. Importantly, unlike empirical models,
the optimization model relies on measurable physiological traits as inputs and performs well in predicting responses
to novel environmental conditions without empirical corrections. Incorporating the optimization model in larger scale
models has the potential for improving the simulation of water and carbon cycles.

Glucose Transporter CST1 Promotes Stomatal Conductance and Photosynthesis

A Glucose Transporter Promotes Stomatal Conductance and Photosynthesis

by Palmer L. (2019)

Linda Palmer

In The Plant Cell, The Plant Cell: In a Nutshell  May 3, 2019 –

Hai Wang et al. identify a regulator of stomatal movement and photosynthesis. Plant Cell

By Hai Wang, Biotechnology Research Institute, Chinese Academy of Agricultural Sciences

Background: Fixation of atmospheric CO2 through photosynthesis is crucial for the survival of plants, and is also pivotal for meeting the ever-increasing food, feed and fuel demands of humans. To achieve optimal photosynthesis, leaf photosynthetic rates need to be tightly controlled according to the level of photoassimilates in plants. It has long been observed that stomatal movement modulates COavailability and consequently the rate of photosynthesis, and several photoassimilates (such as sucrose and glucose) were found to regulate photosynthesis through modulating stomatal movement.

Question: Although feedback regulation of photosynthesis by photoassimilates through stomatal movement has long been observed, our knowledge of the genes and molecular mechanisms involved in this process is far from complete, especially for monocot crop species.

Findings: We cloned and characterized a maize mutant named closed stomata1 (cst1), which exhibits diminished stomatal opening and photosynthesis at the grain-filling stage. Map-based cloning of cst1identified the causal mutation in a Clade I Sugars Will Eventually be Exported Transporters (SWEET) family gene. CST1 encodes a glucose transporter expressed in subsidiary cells, and functions as a positive regulator of stomatal opening. At the grain-filling stage, a deficiency in CST1 leads to reduced photosynthesis, carbon starvation in leaves, and in turn to an early-senescence phenotype. Moreover, CST1 expression is induced by carbon starvation and suppressed by photoassimilate accumulation. Taken together, CST1 plays a key role in the feedback regulation of stomatal movement and photosynthesis by photoassimilates in maize.

Next steps: In our future research, we seek to answer how glucose, the substrate of CST1, modulates the function of subsidiary cells.

CST1 as a missing link in the feedback-regulation of stomatal movement

A Subsidiary Cell-Localized Glucose Transporter Promotes Stomatal Conductance and Photosynthesis

by Wang H., Yan S., Xin H., Huang W., Zhang H., Teng S., Yu Y.-C., Fernie A. R., Lu X., Li P., Li S., Zhang C., Ruan Y.-L., Chen L.-Q, Lang Z. (2019)

Hai Wang, Shijuan Yan, Hongjia Xin, Wenjie Huang, Hao Zhang, Shouzhen Teng, Ya-Chi Yu, Alisdair R. Fernie, Xiaoduo Lu, Pengcheng Li, Shengyan Li, Chunyi Zhang, Yong-Ling Ruan, Li-Qing Chen, Zhihong Lang,


In Plant Cell –


It has long been recognized that stomatal movement modulates CO2 availability and as a consequence the photosynthetic rate of plants, and that this process is feedback-regulated by photoassimilates. However, the genetic components and mechanisms underlying this regulatory loop remain poorly understood, especially in monocot crop species.

Here, we report the cloning and functional characterization of a maize (Zea mays) mutant named closed stomata1 (cst1). Map-based cloning of cst1 followed by confirmation with the clustered regularly interspaced short palindromic repeats (CRISPR)/ CRISPR associated protein 9system identified the causal mutation in a Clade I Sugars Will Eventually be Exported Transporters (SWEET) family gene, which leads to the E81K mutation in the CST1 protein. CST1 encodes a functional glucose transporter expressed in subsidiary cells, and the E81K mutation strongly impairs the oligomerization and glucose transporter activity of CST1.

Mutation of CST1 results in reduced stomatal opening, carbon starvation, and early senescence in leaves, suggesting that CST1 functions as a positive regulator of stomatal opening. Moreover, CST1 expression is induced by carbon starvation and suppressed by photoassimilate accumulation.

Our study thus defines CST1 as a missing link in the feedback-regulation of stomatal movement and photosynthesis by photoassimilates in maize.

The osmotic motor that drives stomatal movement

Exploring biophysical and biochemical components of the osmotic motor that drives stomatal movement

by Raschke K., Hedrich R., Reckmann U., Schroeder J. I. (1988)

In Botanica Acta 101: 283-294 –

The role of CO2 in the light response of stomata

Studies in stomatal behaviour. V. The role of carbon dioxide in the light response of stomata

by Heath O. V. S. (1950)


In Journal of Experimental Botany 1: 29-62 –


It was found that stomata on illuminated leaves, both of Pelargonium and wheat, opened much wider where the leaf surface was enclosed in a small volume of air, as in a normal porometer cup, than elsewhere. This was shown for both species by the infiltration method, and for Pelargonium by Lloyd’s method and direct microscopical observation also.

The effect was shown not to be due to pressure of the porometer cup or glass plate on the leaf, or to temperature differences, nor directly to the lack of movement or high humidity of the enclosed air.

A considerable body of data was collected which appeared to support the hypothesis that the wide opening was due to accumulation of some volatile substance produced by the leaf, but all the results were also consistent with the view that it was caused by reduction in the carbon dioxide content of the enclosed air below the normal 0·03 per cent. owing to photosynthesis. Further crucial experiments with both the porometer and infiltration methods left virtually no doubt that the latter hypothesis was correct.

This extreme sensitivity of stomata to carbon dioxide concentration within the range 0·03 per cent. to zero is discussed in relation to their operation in nature, and a possible biological advantage is suggested.

The bearing of the effect upon porometer investigations is also discussed and it is concluded that for all quantitative or semi-quantitative experimentation it is essential to use a cup detached between readings, or at least swept with air such as surrounds the rest of the leaf, and to have the upper leaf surface above the cup area freely exposed or similarly swept. For qualitative investigation of the light response of stomata the traditional form of cup may be used.

The importance is stressed of allowing porometer readings to reach equilibrium under one set of conditions before changing to another, when investigating the ‘closing’ or ‘opening’ effects of external factors.

Several subsidiary effects, observed in the course of the investigation, are discussed; in particular an effect of humidity upon the rate of response to other factors.