Stomatal patterns in Embryophytes

 

 

Stomatal patterns in Embryophytes: Their evolution, ontogeny and interpretation

Payne W. W. (1979)

Willard W. Payne, New York Bot. Garden, Fairchild Trop. Garden

===

in Taxon 28(1,2/3): 117-132 –

https://www.jstor.org/stable/1219566?seq=1#page_scan_tab_contents

Abstract

The history of study and nomenclature of stomatal concepts has not yet led to full elucidation of cell pattern significance for higher plants.
In this paper, a new ontogenetic system of classification is introduced that makes primary subdivision on the basis of the mode of division of the guard mother cell (GMC) with respect to the wall which cuts it from the meristemoid: diameristic, at right angles; parameristic, parallel to; and anomomeristic, without special orientation to the preceding wall. These are further subdivided on the basis of ontogeny and number of the surrounding cells.
The biology of stomata is discussed as it relates to cell patterning, and fundamental ties are pointed out between stomatal configurations and epidermal ontogeny, especially with regard to whether development is rectate, proceeding in a wave from an intercalary or marginal meristem, or diffuse, proceeding with continued meristematic activity within the expanding tissue over a long period of time.
The concept of perigenous stomata, those in which protodermal cells act directly as GMC’s without prior division, is refuted. The primitive stoma of land plant sporophytes is interpreted to be the simplest type of diameristic, mesoperigenous stoma, in which a protodermal meristemoid divides transversely, cutting off a distal GMC which then divides longitudinally to produce the guard cells. This stoma is suggested as the progenitor type for the Angiospermae, and is the primitive type for at least the Monocotyledonae.
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Plants in Action (1999)

 

 

 

Atwell B. J., Kriemann P. E., Turnbull C. G. N., Eamus D., Bieleski R. L., Farquhar G. (Eds.) – (1999) – Stomatal structure and function – In: Plants in Action, Adaptation in Nature, Performance in Cultivation – MacMillan Education Australia, Melbourne. – http://plantsinaction.science.uq.edu.au/edition1/?q=content/15-2-1-stomatal-structure-and-function – (On our blog : https://plantstomata.wordpress.com/2015/07/19/2224/)

Ozone-induced stomatal sluggishness changes stomatal parameters

 

 

 

Ozone-induced stomatal sluggishness changes stomatal parameters of Jarvis-type model in white birch and deciduous oak

Hoshika Y., Watanabe M., Carrari E., Paoletti E., Koike T. (2017)

Yasutomo Hoshika, Makoto Watanabe, Elisa Carrari, Elena Paoletti, Takayoshi Koike,

in Plant Biology, accepted for publication – DOI: 10.1111/plb.12632

Abstract

Stomatal ozone flux is closely related to ozone injury to plants. Jarvis-type multiplicative model has been recommended for estimating stomatal ozone flux in forest trees. Ozone may change stomatal conductance by both stomatal closure and less efficient stomatal control (stomatal sluggishness). However, current Jarvis-type models did not account for these ozone effects on stomatal conductance in forest trees.

We thus examined seasonal course of stomatal conductance in two common deciduous tree species native to northern Japan (white birch: Betula platyphylla var. japonica; deciduous oak: Quercus mongolica var. crispula) grown under a free-air ozone exposure. We innovatively considered stomatal sluggishness into Jarvis-type model by a simple parameter s, relating to cumulative ozone uptake (defined as POD: phytotoxic ozone dose).

We found that ozone decreased stomatal conductance of white birch leaves after full expansion (-28%). However, such a reduction of stomatal conductance by ozone was diminished in late summer (-10%). At the same time, ozone reduced stomatal sensitivity of white birch to vapor pressure deficit and increased stomatal conductance under low light condition. On the other hand, in deciduous oak, ozone did not change clearly the model parameters.

The consideration of both ozone-induced stomatal closure and stomatal sluggishness improved the model performance to estimate stomatal conductance and to explain the dose-response relationship about ozone-induced decline of photosynthesis of white birch. Our results indicate that the ozone effects on stomatal conductance (i.e., stomatal closure and stomatal sluggishness) are crucial for modelling studies to determine stomatal response in deciduous trees, especially about sensitive species to ozone.

 

Super stomata

iow-stomata-onpg
The stomata of grasses (singular stoma) function more efficiently than those of other plants. – https://www.hhmi.org/sites/default/files/Biointeractive/IOTW/iow-stomata-onpg.jpg

 

Super Stoma

by Raissig M. T., Bergmann D. C. (2017)

Michael T. Raissig, Dominique C. Bergmann,

Department of Biology, Stanford University, Stanford, CA, USA

in hhmi Biointeractive –

https://www.hhmi.org/biointeractive/super-stoma

Stomata are adjustable pores that plants use to control the amount of carbon dioxide they take in for photosynthesis and the amount of water they lose by transpiration. Plants have been around for 400 million years, and judging by their fossil record, all of them have had stomata consisting of two guard cells. The grass family began to diversify in the late Cretaceous, and it is thought that gradual changes in the shape of their guard cells, and the addition of two support cells, have enabled them to more easily adapt to changing environments. In this example, scientists are starting to understand the mechanisms of change by studying the grass Brachypodium distachyon, and have produced stomata with the usual two guard cells (center of the image), but with many support cells (surrounding the guard cells). It is hoped that by understanding how the stomata are formed, it will be practical to produce crops with improved carbon assimilation and water use, which could lead to plants that can more easily adapt to our rapidly changing climate.

Technical Details:
The grass tissue was stained with a fluorescent dye that reveals cell outlines (in magenta) and a fluorescent protein attached to a factor involved with the control of gene expression (in yellow), and imaged using laser scanning confocal microscopy.

Links:
http://web.stanford.edu/group/bergmann/cgi-bin/bergmannlab/
http://news.stanford.edu/2017/03/16/grass-developed-better-way-breathe/
https://asknature.org/strategy/guard-cells-regulate-gas-and-moisture-exc…

 

How grass developed a better way to breathe (stomata)

 

 

Stanford scientists reveal how grass developed a better way to breathe

by Kubota T. (2017)

Taylor Kubota

in http://news.stanford.edu/2017/03/16/grass-developed-better-way-breathe/

Flash back to your first lesson in photosynthesis and you may recall stomata, the holes in the leaves of land-based plants through which they take in carbon dioxide and let out oxygen and water vapor. In the 400 million years since plants colonized the land, these holes have remained largely unchanged, save for one major exception: grasses.

Wheat field

Wheat and other edible grasses have developed pores that make them more drought tolerant.  Stanford scientists have studied these pores with an eye toward future climate change. (Image credit: magdasmith / Getty Images)

 

These plants, which make up about 60 percent of the calories people consume worldwide, have a modified stoma that experts believe makes them better able to withstand drought or high temperatures. Stanford University scientists have now confirmed the increased efficiency of grass stomata and gained insight into how they develop. Their findings, reported in the March 17 issue of Science, could help us cultivate crops that can thrive in a changing climate.

“Ultimately, we have to feed people,” said Dominique Bergmann, professor of biology and senior author of the paper. “The climate is changing and, regardless of the cause, we’re still relying on plants to be able to survive whatever climate we do have.”

The physiological mechanisms by which the circadian clock may regulate stomatal movements

 

 

 

Circadian Rhythms in Stomata: Physiological and Molecular Aspects

Phenomenology, Mechanisms, and Adaptive Significance

Hubbard K. E., Hotta C. T., Gardner M. J., Bark S. J., Dalchau N., Dontamala S., Dodd A. N., Webb A. A. R. (2007)

Katharine E Hubbard, Carlos T Hotta, Michael J Gardner, Seong Jin Baek, Neil Dalchau, Suhita Dontamala, Antony N. Dodd, Alex AR Webb

in Rhythms in Plants, Chapter 8, 157-177

Editors: Prof. Dr. Stefano MancusoDr. Sergey Shabala

Springer Verlag, Heidelberg, ISBN 978-3-540-68069-7

 

Stomata are the major route of gas exchange between the atmosphere and the leaf interior. The size of the stomatal pore is controlled by movements of the stomatal guard cells. The guard cells close the stomatal pore to conserve water during stress.

Under more favourable conditions, the stomatal movements optimise CO2 uptake whilst minimising water loss. The movements of stomata are controlled by an extensive network of signalling pathways responding to diverse stimuli.

One of the regulators of stomata is the circadian clock. We discuss the physiological mechanisms by which the clock may regulate stomatal movements, and the benefits that circadian regulation of stomatal behaviour may confer to the plant.