Studying the role of stomata in controlling leaf water status

Assessment of stomatal control of plant water status

by Jones H. G. (1974)

Hamlyn G. Jones

In New Phytol. 73: 851–859 –


Two methods for studying the role of stomata in controlling leaf water status are compared, using data for field grown spring wheat (Triticum aestivum L.). The first is based on comparisons of leaf water potential and stomatal conductance and their responses to different soil water treatments as obtained by irrigation or by placing plastic rainwater gutters between rows to remove a proportion of the incident rainfall. The second method exploits the varying potential evaporation and the consequent changing leaf water potential and stomatal conductance during the course of a day. Good stomatal control is indicated by large values of the ratio of the amount of variation in stomatal conductance to that of leaf water potential. A particular advantage of the latter method is that it does not require a range of soil water treatments, and it can therefore be more readily used to compare the degree of stomatal control in a range of genotypes. There was generally good agreement between the methods, with the second method showing greater sensitivity.

Stomatal conductances were measured with a continuous flow diffusion porometer which had a thermostatically controlled leaf chamber. This feature had the advantage that conductances could be obtained directly from the output of the humidity sensor without the necessity for routine measurement of, and correction for, leaf temperature


Rapid stomatal responses to humidity

Rapid stomatal responses to humidity

by Fanjul L., Jones H. G. (1982)

East Malling Research Station, Maidstone, UK


In Planta 154: 135-138 –


The response of leaf conductance in apple to rapid changes in atmospheric humidity was studied using a continuous flow porometer. Leaf-air vapour pressure difference was changed by adjusting the humidity of the inlet air or by altering the flow rate of the air through the chamber.

The time course of the response of leaf conductance to leaf-air vapour pressure difference was monitored for periods up to 10 min using a chart-recorder. There were significant changes in leaf conductance within seconds of changing humidity. These were attributed to alterations in stomatal aperture.

Stomatal responses to humidity

Stomatal responses to humidity in Nothofagus menziesii

by Körner C., Bannister P. (1985)

Institut fur Botanik
Universität Innsbruck
Sternwartestrasse 15
A-6020 Innsbruck
Department of Botany
University of Otago
P.O. Box 56, Du


In NZ J Bot 23: 425–429


The diffusive conductance of leaves of Nothofagus menziesii was found to be very sensitive to ambient humidity with stomatal closure commencing at vapour pressure deficits of between 0.5 and 1.0 kPa. Responses were more rapid in leaves from trees growing in humid locations than in those from dry sites.

Altitudinal variation in stomatal conductance

Altitudinal variation in stomatal conductance, nitrogen-content and leaf anatomy in different plant life forms in New-Zealand

by Körner C., Bannister P., Mark A. F. (1986)

Ch. Körner 1, P. Bannister 2, A.F. Mark 2
1 Institut fiir Botanik, Universität Innsbruck, Sternwartestrasse 15, A-6020 Innsbruck, Austria
2 Department of Botany, University of Otago, Dunedin, New Zealand


In Oecologia 69: 577–588 – doi: 10.1007/Bf00410366 –

This study is part of a series of investigations on the influence of altitude on structure and function of plant leaves. Unlike most other mountain areas, the Southern Alps of New Zealand provide localities where physiologically effective moisture stress occurs neither at high nor at low elevation, but the changes in temperature and radiation with elevation are similar or even steeper than in most other regions. In comparison with results from other mountains, where moisture may impair plant functioning at low elevation, this study allows an estimation of the relative role of water for the expression of various leaf features typically associated with alpine plants. Maximum leaf diffusive conductance (g), leaf nitrogen content (LN), stomatal density (n) and distribution, as well as area (A), thickness (d) and specific area (SLA) of leaves were studied. Three different plant life forms were investigated over their full altitudinal range (m): trees, represented by Nothofagus menziesii (1,200 m), ericaceous dwarf shrubs (1,700 m), and herbaceous plants of the genus Ranunculus (2,500 m). In all three life forms g, LN, and n increased, while SLA and A decreased with elevation. Recent investigations have found similar trends in other mountains from the temperate zone, but the changes are larger in New Zealand than elsewhere. Herbs show the greatest differences, followed by shrubs and then trees.

It is concluded that g is dependent upon light climate rather than water supply, whereas SLA and related structural features appear to be controlled by the temperature regime, as they show similar altitudinal changes under different light and moisture gradients. The higher leaf nitrogen content found at high elevations in all three life forms, suggests that metabolic activity of mature leaves is not restricted by low nitrogen supply at high altitude. In general, the leaves of herbaceous plants show more pronounced structural and functional changes with altitude than the leaves of shrubs and trees.

Leaf morphological, stomatal, and anatomical traits in temperate and subtropical forests

Variation in leaf morphological, stomatal, and anatomical traits and their relationships in temperate and subtropical forests

by Liu C., Li Y., Xu L., Chen Z., He N. (2019)

Congcong Liu,1,2

Ying Li,3

Li Xu,1

Zhi Chen,1 

Nianpeng He1,2,4

1Key Laboratory of Ecosystem Network Observation and Modeling, Institute of Geographic Sciences and Natural Resources Research, Chinese Academy of Sciences, Beijing, 100101 China

2University of Chinese Academy of Sciences, Beijing, 100049 China

3The Key Laboratory for Forest Resources& Ecosystem Processes of Beijing, Beijing Forestry University, Beijing, China

4Institute of Grassland Science, Northeast Normal University and Key Laboratory of Vegetation Ecology, Ministry of Education, Changchun, 130024 China


In Sci Rep. 2019; 9: 5803doi: 10.1038/s41598-019-42335-2


Leaf functional traits have attracted the attention of ecologists for several decades, but few studies have systematically assessed leaf morphological traits (termed “economic traits”), stomatal (termed “hydraulic”), and anatomical traits of entire forest communities, thus it is unclear whether their relationships are consistent among trees, shrubs, and herbs, and which anatomical traits should be assigned to economical or hydraulic traits.

In this study, we collected leaf samples of 106 plant species in temperate forests and 164 plant species in subtropical forests and determined nine key functional traits.

We found that functional traits differed between temperate and subtropical forests. Leaf traits also differed between different plant functional groups, irrespective of forest type; dry matter content, stomatal density, and cell tense ratio followed the order trees > shrubs > herbs, whereas specific leaf area and sponginess ratio showed the opposite pattern.

The correlations of leaf traits were not consistent among trees, shrubs, and herbs, which may reflect different adaptive strategies. Principal component analysis indicated that leaf economics and hydraulic traits were uncoupled in temperate and subtropical forests, and correlations of anatomical traits and economic and hydraulic traits were weak, indicating anatomical traits should be emphasized in future studies.

Variation of stomata dimensions and densities under drought stress

Variation of stomata dimensions and densities in tolerant and susceptible wheat cultivars under drought stress

Mehri N., Fotovat R., Saba J., Jabbari F. (2009)

Mehri NastaranFotovat RezaSaba JalalJabbari Farhad,


In Journal of Food, Agriculture & Environment 7(1): 167-170 – ISSN:1459-0255 –


Drought is one of the main limiting factors for plants production. Physiological traits such as number and size of stomata are important in selecting for drought resistance in breeding programs. In a greenhouse factorial experiment with two factors including the irrigation level and cultivar (comprise of 5 tolerant cultivars viz. Azar-2, Sardari, Son-64, 18-Yeknavakht-82, Sabalan, and 5 susceptible cultivars viz. Shahriar, Alvand, Tous, Kaspard, and Pishtaz), the role of stomata in the drought tolerance and the possibility of using of these traits in breeding program were assessed. Water stress was imposed after emergence of the flag leaf, and sampling was performed when the flag leaves were fully expanded. Under the water deficit conditions the stomata length and the area of both upper and lower surfaces of the flag leaves decreased, but it didn’t have effect on stomata density and width on both surfaces. The stomata density and width probably have been determined before drought imposition. The orthogonal comparisons of tolerant and susceptible cultivars showed that stomata length and density on the abaxial surface and stomata width and area on both of the surfaces for tolerant cultivars were highly significantly less than in the susceptible cultivars.

Leaf surface characters, stomata and plant resistance to auto-exhaust pollution

Do leaf surface characters play a role in plant resistance to auto-exhaust pollution?

Pal A., Kulshreshta K., Ahmad K. J., Behl H. M. (2002)

Amit Pal, Kamla Kulshreshtha, K. J. Ahmad, H. M. Behl,

National Botanical Research Institute, Rana Pratap Marg, P.B. 436, Lucknow-226 001, India


In Flora – Morphology, Distribution, Functional Ecology of Plants 97(1): 47-55 –


The significance of micro-morphologica1 leaf surface characters of plants in indication and mitigation of auto-exhaust pollution has been investigated. For the purpose of the study, the following plant species growing along roadsides in low and high traffic density areas have been selected: Asparagus racemosusAzadirachta indicaBougainvillea spectabilisCassia fistulaFicus religiosaNerium indicumPolyalthia longifolia and Thevetia neriifolia. These plants were continuously exposed to automobile emissions. As compared to control plants, the leaf surface structures changed significantly in the exposed plants. The epidermal cells collapsed, cell boundaries were irregularly fused, and a two-fold increase in stomatal frequency and trichome length could be observed. Epicuticular wax also lost its original shape, got disorganised and subsequently eroded, forming patches of a crust on the cuticle. While the surface structural changes were significant, the phenology of these plants remained unaffected by auto-exhaust pollution. The investigated species though manifesting above changes remained normal and healthy and, therefore, they may be recommended for growing along roadsides in areas polluted by automobile emissions.