The Mechanical Diversity of Stomata and Its Significance in Gas-Exchange Control[OA]

By Peter Franks, G. Farquhar. Plant Physiology, 2006

629 citations recorded by the source corpus.

Given that stomatal movement is ultimately a mechanical process and that stomata are morphologically and mechanically diverse, we explored the influence of stomatal mechanical diversity on leaf gas exchange and considered some of the constraints. Mechanical measurements were conducted on the guard cells of four different species exhibiting different stomatal morphologies, including three variants on the classical “kidney” form and one “dumb-bell” type; this information, together with gas-exchange measurements, was used to model and compare their respective operational characteristics. Based on evidence from scanning electron microscope images of cryo-sectioned leaves that were sampled under full sun and high humidity and from pressure probe measurements of the stomatal aperture versus guard cell turgor relationship at maximum and zero epidermal turgor, it was concluded that maximum stomatal apertures (and maximum leaf diffusive conductance) could not be obtained in at least one of the species (the grass Triticum aestivum) without a substantial reduction in subsidiary cell osmotic (and hence turgor) pressure during stomatal opening to overcome the large mechanical advantage of subsidiary cells. A mechanism for this is proposed, with a corollary being greatly accelerated stomatal opening and closure. Gas-exchange measurements on T. aestivum revealed the capability of very rapid stomatal movements, which may be explained by the unique morphology and mechanics of its dumb-bell-shaped stomata coupled with “see-sawing” of osmotic and turgor pressure between guard and subsidiary cells during stomatal opening or closure. Such properties might underlie the success of grasses.

Subfields: Global and Planetary Change, Mechanical Engineering, Molecular Biology

View Paper: https://www.semanticscholar.org/paper/1923009bee355c74fe4bf9a0bdb95df2d6ad8d35

How researchers see this paper

The researchers whose trusted networks rank it highest, strongest advocate first. Every researcher gets a different order.

In Global and Planetary Change

1. D. Beerling
2. T. Lawson
3. Mike Blatt
4. Peter Franks
5. Thomas Eichert
6. V. Fernández

In Mechanical Engineering

1. D. Beerling
2. Peter Franks

In Molecular Biology

1. D. Beerling
2. Peter Franks
3. KK Tanino
4. LE Arve
5. J. E. Watkins
6. T. Lawson
7. C. Cardelús
8. Thomas Eichert

Citations in the corpus

• Maximum leaf conductance driven by CO2 effects on stomatal size and density over geologic time (2009, methodology): “5, using S and D as inputs and p as L/2 (5), a matrix of gwmax was generated and plotted as a graduated-color contour map (Fig.”
• Uptake of Hydrophilic Solutes Through Plant Leaves: Current State of Knowledge and Perspectives of Foliar Fertilization (2009, background): “A recent study showed that the morphological diversity of stomata translates into considerable mechanical and functional diversity regarding leaf gas exchange control (Franks and Farquhar, 2007).”
• Stomatal Responses to Drought Stress and Air Humidity (2011, background): “This is because in Angiosperms and Gymnosperms the guard cells closely interact with their subsidiary cells.”
• Ferns in an Angiosperm World: Cretaceous Radiation into the Epiphytic Niche and Diversification on the Forest Floor (2012, background): “Recent studies are showing that ferns may be significantly less water use efficient than seed plants and that this inefficiency is driven directly by in- efficient stomatal behavior (Franks and Farquhar 2007; Brodribb and McAdam 2011; McAdam and Brodribb 2012).”
• Stomatal Size, Speed, and Responsiveness Impact on Photosynthesis and Water Use Efficiency1[C] (2014, background): “Maximum 130 stomatal conductance is dictated by the size and density of stomata, which in turn can be influenced by 131 the growth environment (e.g. Hetherington and Woodward, 2003; Franks and Farquhar, 2007).”
• Smaller, faster stomata: scaling of stomatal size, rate of response, and stomatal conductance (2013, background): “…Open Access article distributed under the terms of the Creative Commons Attribution Non-Commercial License (http://creativecommons.org/licenses/ by-nc/2.0/uk/) which permits unrestricted non-commercial use, distribution, and reproduction in any medium, provided the original work is properly cited.”