Stomatal versus genome size


Stomatal vs. genome size in angiosperms: the somatic tail wagging the genomic dog?

by Hodgson J. G., Sharafi M., Jalili A., Diaz S., Montserrat-Marti G., Palmer C., Cerabolini B., Pierce S., Hamzehee B., Asri Y., Jamzad Z., Wilson P., Raven J. A., Band S. R., Basconcelo S., Bogard A., Carter G., Charles M., Castro-Diez P., Cornelissen J. H. C., Funes G., Jones G., Khoshnevis M., Pérez-Harguindeguy N., Pérez-Rontomé M. C., Shirvany F. A., Vendramini F., S. Yazdani S., Abbas-Azimi R., Boustani S., Dehghan M., Guerrero-Campo J., Hynd A., Kowsary E., Kazemi-Saeed F., Siavash B.,Villar-Salvador P., Craigie R., Naqinezhad A., Romo-Diez A., de Torres Espuny L., Simmons E. (2010)

J. G. Hodgson1,†,*, M. Sharafi2, A. Jalili3, S. D ́ıaz4, G. Montserrat-Mart ́ı5, C. Palmer6, B. Cerabolini7, S. Pierce7, B. Hamzehee3, Y. Asri3, Z. Jamzad3, P. Wilson8, J. A. Raven9, S. R. Band8, S. Basconcelo10, A. Bogard6, G. Carter6, M. Charles6, P. Castro-D ́ıez5, J. H. C. Cornelissen11, G. Funes4, G. Jones6, M. Khoshnevis3, N. Pe ́rez-Harguindeguy4, M. C. Pe ́rez-Rontome ́5, F. A. Shirvany3, F. Vendramini4, S. Yazdani3, R. Abbas-Azimi3, S. Boustani3, M. Dehghan3, J. Guerrero-Campo4, A. Hynd6, E. Kowsary3, F. Kazemi-Saeed3, B. Siavash3, P. Villar-Salvador5, R. Craigie6, A. Naqinezhad2, A. Romo-D ́ıez12, L. de Torres Espuny5 and E. Simmons6

1 Peak Science and Environment, Station House, Leadmill, Hathersage, Hope Valley S32 1BA, UK,
2 Department of Biology, Faculty of Sciences, University of Mazandaran, Babolsar, Iran,
3 Research Institute of Forests and Rangelands, PO Box 13185- 116, Tehran, Iran,
4 Instituto Multidisciplinario de Biologıa Vegetal (CONICET – UNC) and F.C.E.F.y N., Universidad Nacional de Cordoba, Casilla de Correo 495, Vélez Sarsfield 299, 5000 Cordoba, Argentina,
5 Dept Ecologıa Funcional y Biodiversidad, Instituto Pirenaico de Ecologıa (CSIC) Aptdo. 202, E-50080 Zaragoza, Spain,
6 Department of Archaeology, University of Sheffield, Sheffield S1 4ET, UK,
7 Unità di Analisi e Gestione Biocenosi, Dipartimento di Biologia Strutturale e Funzionale, Universita` degli Studi dell’Insubria, Via J.H. Dunant, 3 – 21100 Varese, Italy,
8 Unit of Comparative Plant Ecology, Department of Animal and Plant Sciences, University of Sheffield, Sheffield S10 2TN, UK,
9 Division of Plant Sciences, University of Dundee at SCRI, Scottish Crop Research Institute, Invergowrie, Dundee DD2 5DA, UK,
10 Ecologıa Agrıcola, Facultad de Ciencias Agropecuarias, Universidad Nacional de Cordoba, CC 509, 5000, Cordoba, Argentina,
11 Department of Systems Ecology, Faculty of Earth and Life Sciences, VU University, De Boelelaan 1085, 1081 HV Amsterdam, The Netherlands and
12 Institut Botànic de Barcelona, Parc Montjuıc, Av. dels Muntanyans s/n 08038, Barcelona, Spain


in Annals of Botany 105: 573–584, 2010 – doi:10.1093/aob/mcq011

† Background and Aims:  Genome size is a function, and the product, of cell volume. As such it is contingent on ecological circumstance. The nature of ‘this ecological circumstance’ is, however, hotly debated. Here, we investigate for angiosperms whether stomatal size may be this ‘missing link’: the primary determinant of genome size. Stomata are crucial for photosynthesis and their size affects functional efficiency.

† Methods:  Stomatal and leaf characteristics were measured for 1442 species from Argentina, Iran, Spain and the UK and, using PCA, some emergent ecological and taxonomic patterns identified. Subsequently, an assessment of the relationship between genome-size values obtained from the Plant DNA C-values database and measurements of stomatal size was carried out.

† Key Results:  Stomatal size is an ecologically important attribute. It varies with life-history (woody species , herbaceous species , vernal geophytes) and contributes to ecologically and physiologically important axes of leaf specialization. Moreover, it is positively correlated with genome size across a wide range of major taxa.

† Conclusions:  Stomatal size predicts genome size within angiosperms. Correlation is not, however, proof of causality and here our interpretation is hampered by unexpected deficiencies in the scientific literature. Firstly, there are discrepancies between our own observations and established ideas about the ecological significance of stomatal size; very large stomata, theoretically facilitating photosynthesis in deep shade, were, in this study (and in other studies), primarily associated with vernal geophytes of unshaded habitats. Secondly, the lower size limit at which stomata can function efficiently, and the ecological circumstances under which these minute stomata might occur, have not been satisfactorally resolved. Thus, our hypothesis, that the optimization of stomatal size for functional efficiency is a major ecological determinant of genome size, remains unproven.


Classification des types stomatiques sur des données morphologiques et ontogénétiques/ Classifying the types of stomates on the basis of their morphology and ontogeny.


Les types stomatiques chez les Angiospermes: leurs variations sur un même épiderme et leur utilisation en systématique. 

Guyot M. (1985)

Michel Guyot

in Bull. Soc. bot. Fr. 132, Act. bot. (2),. 37-48. – DOI: 10.1080/01811789.1985.10826726 –

Un système de classification des types stomatiques est proposé sur des données morphologiques et ontogénétiques. II a été appliqué à diverses familles à partir des variations observées à l’échelle de l’individu et décrites par la formule et le diagramme stomatiques. L’extension de ce système à la systématique des Angiospermes en général exige une même démarche qui prenne en compte la présence des différents types stomatiques à l’échelle de chaque espèce et non seulement la présence de tel ou tel type de stomate.


A system is proposed for classifying the types of stomates on the basis of their morphology and ontogeny. It has been applied to various families using the variations observed at the level of the single plant and describing them by the formula and the diagram of the stomates. Its extension to plant systematics in general requires similar investigations that take into account how the various types of stomates are represented within each species and not only the occurrence of any one type of stomate.

Venation and epidermal characters (e.g. stomata) in Angiosperms


Approaches to the identification of angiosperm leaf remains.

by Dilcher D. L. (1974)

David_Dilcher.jpg – Indiana University Bloomington

in Bot. Rev. 40. 1-157. – DOI: 10.1007/BF02860067 –

During the past 125 years the history of early angiosperms, interpreted through the fossil leaf record has been largely an exercise in paleofloristic studies, ignoring evolution. Imprecise identifications of ancient leaves “matched” to extant genera and families have been used as the basis for reconstructions of paleocommunities and paleoclimates.  However, as the result of careful morphological studies of leaf form, venation and cuticular features new insights into the evolution of angiosperms are now available.
In this paper considerations are given to the usefulness and shortcomings of leaf form, venation and cuticularanalysis as diagnostic tools of plant identification. Many techniques for the study of the morphology of modern and fossil leaves are included in this paper as well as tables outlining features of leaf venation and the epidermis.
Careful morphological studies of leaf form (such as the venation and epidermal characters emphasized in this paper) will provide better understanding of the relationships of living angiosperms and transform the fossil leaf record into useful data that can be used to study
the evolution of the angiosperms.

A theory of stomatal patterning on angiosperm leaves


Stomatal patterning in angiosperms.

by Croxdale J. (2000)

Judith L. Croxdale

in American Journal of Botany 87:1069–1080. – DOI: 10.2307/2656643 –

My thesis is that understanding stomatal patterning requires a holistic perspective. Since stomata are structures critical to the survival of terrestrial plants, they need to be viewed in relation to their function and their interface with other structural components.
With this outlook, I begin by discussing pattern types, means of measuring them, advantages of each type of measurement, and then present patterning from evolutionary, physiological, ecological, and organ views.
I suggest areas where I believe profitable studies might enable us to better understand stomatal patterning.
The final sections of the paper review stomatal patterning on angiosperm leaves and present a theory of patterning. With the abundance of molecular information, and coming genomic sequences and new tools, an opportunity exists to dissect the process of how cells are selected to become different from their neighbors and assume a fate critical to plant survival.
Understanding this biological process at the molecular level requires comprehending the broad base on which stomatal patterning rests.

Stomatal development in early-divergent angiosperms


Ultrastructure of stomatal development in early-divergent angiosperms reveals contrasting patterning and pre-patterning

by Rudall P. J.,paula-rudall-cropped

Knowles E. V. W.


in Annals of Botany 111: 1031-1043. 

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Background and Aims

Angiosperm stomata consistently possess a pair of guard cells, but differ between taxa in the patterning and developmental origin of neighbour cells. Developmental studies of phylogenetically pivotal taxa are essential as comparative yardsticks for understanding the evolution of stomatal development.



We present a novel ultrastructural study of developing stomata in leaves of Amborella (Amborellales), Nymphaea and Cabomba(Nymphaeales), and Austrobaileya and Schisandra (Austrobaileyales), representing the three earliest-divergent lineages of extant angiosperms (the ANITA-grade).


Key Results

Alternative developmental pathways occur in early-divergent angiosperms, resulting partly from differences in pre-patterning and partly from the presence or absence of highly polarized (asymmetric) mitoses in the stomatal cell lineage. Amplifying divisions are absent from ANITA-grade taxa, indicating that ostensible similarities with the stomatal patterning of Arabidopsis are superficial. In Amborella, ‘squared’ pre-patterning occurs in intercostal regions, with groups of four protodermal cells typically arranged in a rectangle; most guard-mother cells are formed by asymmetric division of a precursor cell (the mesoperigenous condition) and are typically triangular or trapezoidal. In contrast, water-lily stomata are always perigenous (lacking asymmetric divisions). Austrobaileya has occasional ‘giant’ stomata.



Similar mature stomatal phenotypes can result from contrasting morphogenetic factors, although the results suggest that paracytic stomata are invariably the product of at least one asymmetric division. Loss of asymmetric divisions in stomatal development could be a significant factor in land plant evolution, with implications for the diversity of key structural and physiological pathways.

Stomatal Patterning in Tree Species of Angiosperms


Stomatal Patterning: An Important Taxonomic Tool for Systematical Studies of Tree Species of Angiosperms

by Khan F., Yousaf Z., Ahmed H. S., Arif A., Rehman H. A., Younas A., Rashid M., Tariq Z., Raiz N. (2014)

Faiza Khan

Zubaida Yousaf Zubaida_Yousaf4

Hafiza Ahmed

Hafiza A. Rehman

Madiha Rashid

Nadia Raiz

Ayesha Arif

Afifa Younas

Zoya Tariq


in Annual Research & Review in Biology 4(24): 4034-4053, 2014.


Taxonomic information provides the base line for most of the studies in biological sciences. Most of taxonomic information based on phenotypic characteristics of plants. As phenotypic markers are under the influence of environment, therefore it may leads toward the taxonomic confusion. Therefore, present study was carried out to determine the effect of environment on types of stomata, number, size, and stomata patterning which is very useful feature in taxonomy.

In the present study thirty arboreal species of dicot flora (from tropical and subtropical regions) belonging to eight orders and fifteen families are evaluated by using systematic tool i.e. stomatal pattering. Stomata play a vital role in gas exchange of dicot plants.

Within dicot flora, eight shapes of stomata are observed (anomocytic, anomotetracytic, actinocytic, amphianisocytic, brachyparacytic, anisocytic, amphicyclocytic and staurocytic).

In leaves, the pattern of stomatal distribution is highly variable between arboreal species of dicot but is regulated by a mechanism of one cell spacing between stomata. Epidermal anatomical marker showed the different mode of stomata patterning. Hence, this differential marker can be utilized to differentiate taxonomically complicated species.

Stomata and other specialized structures

Photo credit: Am. J. Bot.

Figs. 1–4. Illustrations of specialized leaf epidermal structures and their characters in surface view. 1. Ethereal oil cell complex typical of those in Austrobaileyales comprising oil cell (o), depicted with a dashed line to indicate that the majority of the cell lies below the epidermis, its nucleus (n), base (b) formed by anticlinal contact cell walls, and cuticular striations (s). A radial wall (r) and tangential wall (t) are indicated. 2. Trichome complex typical of Amborellaceae and Trimeniaceae showing abscission scar (a), foot cell to which the trichome was attached (f), and a strongly specialized contact cell (Sc). 3.Mucilage hair complex typical of Cabombaceae with two disk-shaped cells (d) to which the mucilage hair is attached, and a foot cell (f), level with the epidermis, upon which the disk-shaped cells rest. 4. Hydropote complex typical of Nymphaeaceae with base (b) formed by anticlinal contact cell walls, the lens-shaped cell (L), and the bowl-shaped cell (Bc). In surface view, the Bc often appears as a dark ring surrounding the L. A subepidermal foot cell (f) lies beneath the Bc and L.

Specialized structures in the leaf epidermis of basal angiosperms: morphology, distribution, and homology

by Carpenter, K. J. (2006)

in Am. J. Bot. May 2006 vol. 93 no. 5 665-681.



The morphology of specialized structures in the leaf epidermis of 32 species of basal (ANITA: Amborella, Nymphaeales, Illiciales, Trimeniaceae, and Austrobaileyaceae) angiosperms, representing all seven families and 11 of 14 genera, was investigated using light and scanning electron microscopy. Distribution, density, and size of structures were also measured, and character evolution was analyzed. Hydropotes are a synapomorphy of Nymphaeales and ethereal oil cells are a synapomorphy of Austrobaileyales, but uniseriate nonglandular trichomes appear to have arisen independently several times.

Specialized structures are frequently characterized by adjacent epidermal cells that have striking similarities in their form and arrangement (i.e., architecture) to subsidiary cells of certain types of stomatal complexes.

Additionally, forms intermediate to oil cells and stomata, to trichomes and stomata, and to hydropotes and oil cells are present in some taxa. Thus, all of these specialized structures and their adjacent epidermal cells form complexes that may be homologous with, and evolutionarily derived from stomatal complexes, and the specialized structure, or portion thereof, may be homologous to the stoma or guard mother cell.

Improved knowledge of the morphology and evolution of these structures in the earliest branching extant angiosperm lineages has a bearing on many diverse areas of botany.

Read the full article: Am. J. Bot.