Ligands under 140 amino acids enforcing stomatal patterning.



Plant twitter: ligands under 140 amino acids enforcing stomatal patterning.

by Rychel A. L., Peterson K. M., Torii K. U. (2010)

Department of Biology, University of Washington, Seattle, WA 98195, USA.

  • Amanda L. Rychel, University of Washington, Seattle
  • kylee_peterson
    Kylee M. Peterson, Harvard University Herbaria

    Keiko Torii
    Keiko U. Torii, University of Washington, Seattle

in Journal of Plant Research,123(3): 275–280 -doi: 10.1007/s10265-010-0330-9. –


Stomata are an essential land plant innovation whose patterning and density are under genetic and environmental control.

Recently, several putative ligands have been discovered that influence stomatal density, and they all belong to the EPIDERMAL PATTERNING FACTOR-LIKE family of secreted cysteine-rich peptides.

Two of these putative ligands, EPF1 and EPF2, are expressed exclusively in the stomatal lineage cells and negatively regulate stomatal density.

A third, EPFL6 or CHALLAH, is also a negative regulator of density, but is expressed subepidermally in the hypocotyl.

A fourth, EPFL9 or STOMAGEN, is expressed in the mesophyll tissues and is a positive regulator of density.

Genetic evidence suggests that these ligands may compete for the same receptor complex. Proper stomatal patterning is likely to be an intricate process involving ligand competition, regional specificity, and communication between tissue layers.

EPFL-family genes exist in the moss Physcomitrella patens, the lycophyte Selaginella moellendorffii, and rice, Oryza sativa, and their sequence analysis yields several genes some of which are related to EPF1, EPF2, EPFL6, and EPFL9.

Presence of these EPFL family members in the basal land plants suggests an exciting hypothesis that the genetic components for stomatal patterning originated early in land plant evolution.



Stomata in Aconogonon and Bistorta (Polygonaceae)

Photo credit: Google

Aconogonon divaricatum1UME.jpg


Micromorphological Investigation of Foliar Anatomy of Genera Aconogonon and Bistorta of Family Polygonaceae.

by Yasmin G., Khan M. A., Shaheen N., Hayat M. Q. (2009)

Ghazalah YasminQuaid-i-Azam University (Islamabad, Pakistan)

Nighat ShaheenUniversity of Sussex (Brighton, United Kingdom)

  • Muhammad_Khan249
    Muhammad Azim Khan, Khyber Pakhtunkhwa Agricultural University, Peshawar, Pakistan
Muhammad Qasim Hayat, National University of Sciences and Technology, Islamabad · Department of Plant Biotechnology, Pakistan


in Int. J. Agric. Biol., 11: 285–289 –

Leaf epidermal studies have been carried out on six species belonging to two genera of the family Polygonaceae.
The use of light microscopy has made possible in depth to study leaf surface features such as shape of epidermal cells, stomatal pattern, their distribution on adaxial and abaxial leaf surface and trichomes types.
Epidermal cell shapes are variable but generally polygonal.
Six different stomatal patterns are reported for Aconogonon (Meisn.) Reichenb. and Bistorta Adans.
Variation among glandular and non-glandular trichomes was also noted.
Cyclocytic stomata are recorded first time in Aconogonon alpinum (All.) Schur.
This anatomical study has taxonomic importance, on the basis of which identification keys are prepared.

Stomata in Camptotheca (Nyssaceae) – (in Chinese)

Photo credit: Google

Camptotheca acuminata, cancer tree


The epidermal structure of Camptotheca acuminata leaf.

by Xi M. L., Bao S. K., Lin D. D. (1997)

in Xinan Shifan Daxue Xuebao J. South west China Normal Univ. (Natural Science) 22: 58-61 –

The epidermal structure of mature leaf of Camptotheca acuninata has been examined with LM. and SEM.
Observed in the present work were epidermal cells, stomatal apparatuses, epidermal hairs, cuticular membrane and wax ornaments of upper and lower epidermis.
It is found that there are significant morphological differences between the upper and lower epidermis layer.
The stomata are restricted to the lower epidermis.
The type of stomatal apparatuses is anomocytic. Two stomata set close to each other can be observed.
The unicellular non-glandular trichomes are distributed in the upper and lower epidermis.

Stomatal functioning and yield in Manihot (Euphorbiaceae)

Photo credit: Google

Cassava (Manihot utilissima)


Growth and productivity of tapioca (Manihot utilisima) . II. Stomatal functioning and yield

by Williams C. N. (1971)

C. N. Williams, University of Malaya

in Experimental Agriculture 7: 49-62 – DOI: –

The stomatal functioning of high, medium and low yielding clones of tapioca was examined to see whether yield could be associated with conductivity and/or resistance to moisture stress.

A sensitive falling pressure porometer was used to measure stomatal conductivity to the viscous flow of air at small pressure differences. No marked differences were observed which could account for the large range in yields shown by the varieties, but stomatal functioning could be related to canopy type and to planting conditions.

In general the conductivity values of all three varieties were very low compared to many other crop species, which suggests that increases in canopy efficiency and yield could be obtained in certain environments by an increase in leaf conductivity.

Stomatal ultrastructure in Paphiopedilum

Photo credit: Google

Paphiopedilum venustum

A light and electron microscopy study of the epidermis of Paphiopedilum spp. with emphasis on stomatal ultrastructure.

by Rutter J. C.,Willmer C. M. (1979)

J. C. Rutter, C. M. Willmer

in Plant, Cell and Environment 2(3): 211-219 – DOI: 10.1111/j.1365-3040.1979.tb00072.x –


Light and fluorescence microscopy studies indicated that chlorophyll was absent from the guard cells of the lady slipper orchids, Paphiopedilum insigne (Wall.) Pfitz, P. insigne (hybrid), P. venustum (Wall.) Pfitz and P. harrisseanum Hort. In the guard cells of P. aureum hyeanum Hort., however, very slight red fluorescence suggested that chlorophyll and hence chloroplasts were present.

Ultrastructural studies of the lower epidermis of P. insigne (hybrid) confirmed the absence of chloroplasts in guard and epidermal cells although plastids of an unusual structure were found in these cells. In fully developed epidermal cells the plastids contained large amounts of a fibrous, possibly proteinaceous substance, spherical, lightly staining vesicles and an electron-dense material located in reticulate and non-reticulate regions. Additionally, latticed crystalline inclusions and plasto-globuli were occasionally observed in the epidermal cell plastids. In plastids of fully developed guard cells the fibrous material, starch and plastoglobuli were present.

From the earliest stages of development of the epidermal tissue starch was present in both epidermal cell and guard cell plastids. At maturity, however, starch had accumulated to greater levels in the guard cell plastids and had entirely disappeared in the epidermal cell plastids. In differentiating epidermal tissue, plasmodesmata were found between neighbouring epidermal cells and between guard and epidermal cells. At maturity, plasmodesmata between guard and epidermal cells were not observed.

Mitochondria were particularly abundant in guard cells. Large oil drops developed in guard and epidermal cells, being especially abundant in the former at maturity.

Our results confirm the observations of Nelson & Mayo (1975) that certain lady slipper orchids possess functional stomata the guard cells of which do not contain chloroplasts.

Changes in stomatal density under various CO2 regimes with natural solar irradiance



Changes in stomatal density of rice grown under various CO2 regimes with natural solar irradiance

by Rowland-Banford A. J;, Nordenbrock C., Baker J. T., Bowes G., Allen L. H. Jr. (1990)

Amanda J. Rowland-Bamford, Cassandra Nordenbrock, †  Jeffrey T. Baker,†  George Bowes, ‡  L.Hartwell Jr. Allen §

Department of Agronomy, Building 164, University of Florida, Gainesville, FL 32611, U.S.A.
Department of Botany, University of Florida, Gainesville, FL 32611, U.S.A.
United States Department of Agriculture, Agricultural Research Service, University of Florida, Gainesville, FL 32611, U.S.A.



in Environmental and Experimental Botany 2: 175-180 – –


Rice (Oryza sativa L. cv. IR-30), grown from seed under natural solar irradiance, was exposed to CO2 concentrations ranging from 160 to 900 μl CO2/l air from 9 days after planting until senescence.

Stomatal density was determined from leaf impressions at two growth stages: on leaf number 7 (31 days after planting), and on flag leaves (104 days after planting).

Increasing CO2 concentrations resulted in a rise in stomatal density of leaves at both growth stages. The effect was greatest on the flag leaves, which exhibited a 54% increase in abaxial stomatal density (from 550 to 810 stomata/mm2) at 500 as compared with 160 μl CO2/l.

Stomatal density increased with increasing CO2 up to 330 μl CO2/l; enrichment above this level resulted in no further significant increase in stomatal density.

For both leaf ages, the abaxial stomatal density was more influenced by increases in CO2 than the adaxial surface. The increase in stomatal density was largely the result of a rise in the number of stomata per row, although on the abaxial surface more rows across the leaf also contributed to the response.

Flag leaf area was not significantly different among the CO2 treatments, so the number of stomata per leaf followed similar trends to the stomatal density.

This indicated the CO2effect was on stomatal, rather than leaf area, development.

The response of stomatal density to rising CO2 seems to be a species-dependent phenomenon, that varies with leaf surface and CO2 range utilized.

Phytochrome involvement in stomatal movement



Phytochrome involvement in stomatal movement in Pisum sativum, Vicia faba, and Pelargonium sp.

by Roth-Bejerano N., Itai C.. (1987)

Nurit Roth-Bejerano, Chanan Itai

in Physiol. Plant. 70: 85-89 – DOI: 10.1111/j.1399-3054.1987.tb08701.x –


Red and blue light triggered the opening of isolated stomata of Pisum sativum L. cv. Peleg Alvador, Vicia faba L. (unknown cultivar) and Pelargonium sp.

The stimulatory effect of short irradiation with red or blue light was reversed by a subsequent short irradiation with far-red light. In Pisum the stimulatory effect of a continuous irradiation with red or blue light was also abolished by a concomitant far-red light.

In leaf pieces of P. sativum blue light was more effective than red, but not in isolated guard cells. In the presence of mesophyll, DCMU inhibited stomatal opening in red light more than in blue, and thus increased the relative response to blue light. This was less evident in isolated guard cells.