The relationships between quantitative characteristics of stomata and epidermal cells of leaf epidermis

The stomatal index of the leaf is the ratio of the number of stomata to the total number of stomata and epidermal cells. Comparing with the stomatal density, the stomatal index is relatively constant in environmental conditions and the age of the leaf and, therefore, of diagnostic characteristics for a given genotype or species. Traditional assessment methods involve manual counting of the number of stomata and epidermal cells in microphotographs, which is labor-intensive and time-consuming. Although several automatic measurement algorithms of stomatal density have been proposed, no stomatal index pipelines are currently available. The main aim of this research is to develop an automated stomatal index measurement pipeline. The proposed method employed Faster regions with convolutional neural networks (R-CNN) and U-Net and image-processing techniques to count stomata and epidermal cells, and subsequently calculate the stomatal index. To improve the labeling speed, a semi-automatic strategy was employed for epidermal cell annotation in each micrograph. Benchmarking the pipeline on 1,000 microscopic images of leaf epidermis in the wheat dataset (Triticum aestivum L.), the average counting accuracies of 98.03 and 95.03% for stomata and epidermal cells, respectively, and the final measurement accuracy of the stomatal index of 95.35% was achieved. R2 values between automatic and manual measurement of stomata, epidermal cells, and stomatal index were 0.995, 0.983, and 0.895, respectively. The average running time (ART) for the entire pipeline could be as short as 0.32 s per microphotograph. The proposed pipeline also achieved a good transferability on the other families of the plant using transfer learning, with the mean counting accuracies of 94.36 and 91.13% for stomata and epidermal cells and the stomatal index accuracy of 89.38% in seven families of the plant. The pipeline is an automatic, rapid, and accurate tool for the stomatal index measurement, enabling high-throughput phenotyping, and facilitating further understanding of the stomatal and epidermal development for the plant physiology community. To the best of our knowledge, this is the first deep learning-based microphotograph analysis pipeline for stomatal index assessment.

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Micromorphology of endemic Centaurea glaberrima subsp. divergens (Asteraceae)

Acta Botanica Croatica ◽

10.37427/botcro-2021-028 ◽

2022 ◽

Vol 81 (1) ◽

Author(s):

Milan Gavrilović ◽

Pedja Janaćković

Keyword(s):

Cell Walls ◽

Glandular Trichomes ◽

Pollen Grains ◽

Involucral Bract ◽

Epidermal Cells ◽

Leaf Epidermis ◽

Abaxial Surface ◽

Reproductive Structures ◽

Anomocytic Stomata ◽

First Time

In this study, the micromorphology of the vegetative and reproductive structures of the endemic Centaurea glaberrima Tausch subsp. divergens (Vis.) Hayek (Asteraceae), using scanning electron microscope (SEM), is presented for the first time. Uniseriate whip-like non-glandular and biseriate glandular trichomes are found on the surface of all aboveground parts (stem, leaves, peduncles, involucral bract). On the adaxial leaf epidermis ribbed thickenings (striation pattern) of outer periclinal cell walls, slightly curved anticlinal cell walls and anomocytic stomata are noticed. Rugose abaxial surface with thorny protuberances of the involucral bract is documented. Corolla is glabrous with longitudinally parallel epidermal cells with distinct straight outline. Isopolar, radially symmetric and tricolporate microechinate pollen grains are seen. Short stylar hairs, without cuticular striations, are present along the outer sides of the style, while the inner sides (abaxial surface) constitute the papillate stigmatic surface. Microcharacters found in cypsela are as follows: slightly ribbed body; rotund base; lateral and concave insertion; short, unicellular curly acute trichomes; smooth epidermis; fine-sulcate ornamentation; rod shaped epidermal cells with short, obtuse end walls and straight anticlinal walls; poorly developed minutely dentate pericarp rim; and dimorphic pappus with bristles of different length and morphology, with pinnules restricted to the margins of the bristles. The results obtained contribute to knowledge about the micromorphology of the studied endemic species and provide features for its better identification. The taxonomic significance of the analyzed characters is discussed. Some well defined microcharacters of the studied species might have taxonomic value

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Light and electron microscopy of the spermogonial stage of Gymnoconia peckiana, one of the causes of orange rust of Rubus

Botany ◽

10.1139/b08-011 ◽

2008 ◽

Vol 86 (5) ◽

pp. 533-538 ◽

Cited By ~ 1

Author(s):

Charles W. Mims ◽

Elizabeth A. Richardson

Keyword(s):

Cell Wall ◽

Epidermal Cell ◽

Leaf Surface ◽

Light And Electron Microscopy ◽

Epidermal Cells ◽

Wall Material ◽

Cell Wall Material ◽

Leaf Epidermis ◽

Single Nucleus ◽

Epidermal Cell Wall

Hyphae of Gymnoconia peckiana (Howe in Peck) Trotter spread from infected Rubus argutus Link. stems into leaf primordia where they proliferated in an intercellular fashion as leaves differentiated. Hyphae were septate, and each compartment appeared to contain a single nucleus. Hyphae gave rise to numerous haustoria that resembled the monokaryotic haustoria of other rust fungi. Hyphae located immediately adjacent to the upper and lower leaf epidermis gave rise to spermogonial initials. Each initial consisted of a small group of tightly packed hyphae that developed in an intercellular space adjacent to the epidermis. As an initial enlarged, the proliferating hyphae pushed their way between, as well as into, epidermal cells. Invaded epidermal cells soon died. A layer of spermatiophores then developed within each young spermogonium and appeared to push the epidermal cell wall material and leaf cuticle covering the spermogonium out from the leaf surface. Once mature, spermatiophores gave rise to a succession of uninucleate spermatia that emerged from the tip of each spermatiophore. Spermatia initially accumulated beneath the layer of epidermal cell wall material and cuticle that covered the developing spermogonium and appeared to push this layer further out from the leaf surface until it ruptured. A few receptive hyphae were observed in mature spermogonia.

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Effects of turgor potentials of epidermal cells neighbouring guard cells on stomatal opening in detached leaf epidermis and intact leaflets of Vicia faba L. (faba bean)

Plant Cell & Environment ◽

10.1111/j.1365-3040.1996.tb00018.x ◽

1996 ◽

Vol 19 (12) ◽

pp. 1399-1407 ◽

Cited By ~ 9

Author(s):

M. KLEIN ◽

G. CHENG ◽

M. CHUNG ◽

G. TALLMAN

Keyword(s):

Vicia Faba ◽

Faba Bean ◽

Guard Cells ◽

Epidermal Cells ◽

Stomatal Opening ◽

Leaf Epidermis ◽

Detached Leaf ◽

Vicia Faba L

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Leaf epidermal characters of Brazilian species of Solanum section Torva as taxonomic evidence

Botany ◽

10.1139/b2012-046 ◽

2012 ◽

Vol 90 (9) ◽

pp. 806-814 ◽

Cited By ~ 3

Author(s):

Kiriaki Nurit-Silva ◽

Rafael Costa-Silva ◽

Ionaldo J.L.D. Basílio ◽

Maria de Fátima Agra

Keyword(s):

Cell Walls ◽

Wave Pattern ◽

Morphological Characters ◽

Epidermal Cells ◽

Leaf Epidermis ◽

Taxonomic Significance ◽

Abaxial Surface ◽

Solanum Torvum ◽

Different Types ◽

Additional Support

To evaluate their taxonomic significance, the yet unknown epidermal characters of the leaves of 10 species of Solanum section Torva Nees (Solanaceae) from Brazil were determined using light and scanning electron microscopy. Our results indicated that the leaf epidermis showed epidermal cells of straight to wavy outlines. The curved pattern of anticlinal cell walls was predominant on the adaxial surface, and the wave pattern was predominant on the abaxial surface. Leaves are amphistomatic in six species ( Solanum acutilobum Dunal, Solanum bonariense L., Solanum guaraniticum A. St.-Hil., Solanum metrobotryon Dunal, Solanum scuticum M. Nee, and Solanum torvum Sw.) and hypostomatic in four species ( Solanum adspersum Witasek, Solanum paniculatum L., Solanum subumbellatum Vell., and Solanum variabile Mart.). Four different types of stomata (anisocytic, anomocytic, paracytic, and diacytic) were recognized, with the anisocytic type predominant on adaxial and abaxial surfaces. The combination of some micro-morphological characters such as density, distribution and type of stellate trichomes, the anticlinal walls of epidermal cells, and also the type and distribution of stomata proved to be the most useful and distinctive characters for the separation of species. This set of characters also may help as additional support in quality control of species having medicinal importance.

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Micromorphologie des épidermes foliaires chez quelques espèces de Medicago

Canadian Journal of Botany ◽

10.1139/b83-390 ◽

1983 ◽

Vol 61 (12) ◽

pp. 3461-3470 ◽

Cited By ~ 2

Author(s):

Catherine Damerval

Keyword(s):

Guard Cell ◽

Stomatal Density ◽

Epidermal Cells ◽

Cell Length ◽

Leaf Epidermis ◽

Trichome Density ◽

Stomatal Index ◽

Annual Species ◽

Abaxial Epidermis ◽

Stomatal Complex

The micromorphology of the abaxial epidermis of the first and sixth leaf has been studied in seven annual species of Medicago L. The pattern of the epidermal cells and of the stomatal complex does not allow differentiation of the taxa. Three main types of trichomes are recognized on the two foliar levels; their localization on the first leaf epidermis allows identification of five taxa out of seven. Four quantitative variables are also examined: stomatal density, trichome density, guard cell length, and stomatal index. The variable having the best discriminant value is the guard cell length on the first leaf. It is possible to identify each of the seven species by a combination of two features: the localization of the types of trichomes on the first leaf and the stomatal density on the sixth leaf.

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Differentiation in leaf epidermis

Australian Journal of Botany ◽

10.1071/bt9650143 ◽

1965 ◽

Vol 13 (2) ◽

pp. 143 ◽

Cited By ~ 9

Author(s):

R Shanks

Keyword(s):

Cell Elongation ◽

Nuclear Protein ◽

Guard Cells ◽

Epidermal Cells ◽

Leaf Epidermis ◽

Final State ◽

Cytoplasmic Material ◽

Nuclear Rna ◽

Nucleolar Volume ◽

Large Nucleolus

Microphotometric studies of the leaf epidermis of four monocotyledons indicate that differentiation is accompanied by DNA increases. High polyploidy (over 16-ploid) may be reached in epidermal cells of Galtonia candicans. DNA is approximately paralleled by total nuclear protein increases. The large nucleolus apparently contains most of the nuclear RNA of Galtonia, except at mitosis, when chromosomal RNA becomes apparent. Nucleolar volume increases rapidly at first until the cell is midway in development, when it levels off or may even fall. The nucleolus buds and loses volume in mature guard cells. Cell elongation, and DNA and protein increases, cease at maturity. The final state of differentiation may be related to the initial supply of nucleolar and cytoplasmic material received at mitosis, as well as to environmental differences such as position between or over veins. Simple stomata may result from the early initiation of polyploidy in epidermal cells, and suppression of induction by guard cells.

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Leaf Epidermis of the RheophyteDyckia brevifoliaBaker (Bromeliaceae)

The Scientific World JOURNAL ◽

10.1155/2013/307593 ◽

2013 ◽

Vol 2013 ◽

pp. 1-7 ◽

Cited By ~ 1

Author(s):

Ghislaine Maria Lobo ◽

Thaysi Ventura de Souza ◽

Caroline Heinig Voltolini ◽

Ademir Reis ◽

Marisa Santos

Keyword(s):

Fast Moving ◽

Epidermal Cells ◽

Leaf Epidermis ◽

Streams And Rivers ◽

Water Currents ◽

Peltate Trichomes

Some species ofDyckiaSchult. f., includingDyckia brevifoliaBaker, are rheophytes that live in the fast-moving water currents of streams and rivers which are subject to frequent flooding, but also period of low water. This study aimed to analyze the leaf epidermis ofD. brevifoliain the context of epidermal adaptation to this aquatic plant’s rheophytic habitat. The epidermis is uniseriate, and the cuticle is thickened. The inner periclinal and anticlinal walls of the epidermal cells are thickened and lignified. Stomata are tetracytic, located in the depressions in relation to the surrounding epidermal cells, and covered by peltate trichomes. While the epidermal characteristics ofD. brevifoliaare similar to those of Bromeliaceae species, this species has made particular adaptations of leaf epidermis in response to its rheophytic environment.

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ANÁLISE FOTÔNICA E ULTRA-ESTRUTURAL DA EPIDERME FOLIAR DE Galinsoga parviflora CAV. E G. ciliata (RAF.) BLAKE, ASTERACEAE

Visão Acadêmica ◽

10.5380/acd.v5i1.541 ◽

2004 ◽

Vol 5 (1) ◽

Author(s):

M. Do R. DUARTE ◽

J. F. LOPES

Keyword(s):

Glandular Trichomes ◽

Medicinal Herbs ◽

Epidermal Cells ◽

Ultrastructural Analysis ◽

Hepatic Insufficiency ◽

Leaf Epidermis ◽

Mature Leaves ◽

Anomocytic Stomata ◽

Face View

Galinsoga parviflora Cav. e G. ciliata (Raf.) Blake são herbáceas medicinais, empregadas popularmente no tratamento de ulcerações cutâneas e distúrbios hepáticos. Este trabalho teve por objetivo caracterizar a epiderme foliar dessas espécies, por meio de análise fotônica e ultra-estrutural. Folhas adultas foram fixadas e submetidas a técnicas usuais de microscopia fotônica e de varredura. Ambas as espécies apresentam epiderme foliar uniestratificada e revestida por cutícula delgada e levemente estriada. Em vista frontal, as células epidérmicas revelam contorno sinuoso e estômatos anomocíticos ocorrem em ambas as superfícies. Tricomas tectores pluricelulares e unisseriados predominam na face adaxial. Esse anexo epidérmico é comparativamente mais numeroso em G. ciliata. OPTICAL AND ULTRASTRUCTURAL ANALYSIS OF THE LEAF EPIDERMIS OF Galinsoga parviflora CAV. AND G. ciliata (RAF.) BLAKE, ASTERACEAE Abstract Galinsoga parviflora Cav. and G. ciliata (Raf.) Blake are medicinal herbs, popularly employed for treating cutaneous ulcers and hepatic insufficiency. This work has aimed to characterize the leaf epidermis of these species, by means of optical and ultrastructural analysis. Mature leaves were fixed and undergone usual optical and scanning microtechniques. Both species have got uniseriate leaf epidermis, coated by thin and slightly striated cuticle. In face view, the epidermal cells show sinuous contour and anomocytic stomata are seen on both surfaces. Pluricellular and uniseriate non-glandular trichomes predominate on the upper side. This epidermal appendage is comparatively more frequent in G. ciliata.

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Morphological variability of the leaf epidermis in selected taxa of the genus Ficus L. (Moraceae) and its taxonomic implications

Acta Societatis Botanicorum Poloniae ◽

10.5586/asbp.2006.038 ◽

2011 ◽

Vol 75 (4) ◽

pp. 309-324 ◽

Cited By ~ 11

Author(s):

Małgorzata Klimko ◽

Mariola Truchan

Keyword(s):

Cell Walls ◽

Quantitative Traits ◽

Morphological Variability ◽

Epidermal Cells ◽

Leaf Epidermis ◽

Qualitative And Quantitative ◽

Size And Shape ◽

Taxonomic Implications

The leaf epidermis of 36 taxa (species, subspecies, varieties and cultivars) of the genus Ficus (subgenera Ficus, Synoecia, Sycomorus, Pharmacosycea and Urostigma) was observed under LM and SEM. Characteristics of the epidermis are of particular taxonomic as well as phylogenetic interest because they differ conspicuously between species. The differences are especially prominent in the size and shape of epidermal cells, the shape of cell walls, peristomatal cuticular rim, the distribution and position of stomata, lithocysts, hydathodes, trichomes, and the types of wax, cuticle and trichomes. Results of this study provided data on new qualitative and quantitative traits of the leaf epidermis in the selected taxa, and confirmed the classification suggested by Berg (1989).

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