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1.
PLoS One ; 15(8): e0237173, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32845897

RESUMO

Gentian is an important ornamental flower in Japan. The corolla of the majority of cultivated Japanese gentians have green spots, which are rarely encountered in flowers of other angiosperms. Little information is available on the functional traits of the green spots. In this study, we characterized the green spots in the Japanese gentian corolla using a number of microscopic techniques. Opto-digital microscopy revealed that a single visible green spot is composed of approximately 100 epidermal cells. The epidermal cells of a green spot formed a dome-like structure and the cell lumen contained many green structures that were granular and approximately 5 µm in diameter. The green structures emitted red autofluorescence when irradiated with 488 nm excitation light. Transmission electron microscopy revealed that the green structures contained typical thylakoids and grana, thus indicating they are chloroplasts. No grana were observed and the thylakoids had collapsed in the plastids of epidermal cells surrounding green spots. To estimate the rate of photosynthetic electron transfer of the green spots, we measured chlorophyll fluorescence using the MICROSCOPY version of an Imaging-PAM (pulse-amplitude-modulated) fluorometer. Under actinic light of 449 µmol m-2 s-1, substantial electron flow through photosystem II was observed. Observation of green spot formation during corolla development revealed that immature green spots formed at an early bud stage and developed to maturity associated with chloroplast degradation in the surrounding epidermal cells. These results confirmed that the Japanese gentian corolla contains functional chloroplasts in restricted areas of epidermal cells and indicated that a sophisticated program for differential regulation of chloroplast formation and degradation is operative in the epidermis.


Assuntos
Flores/citologia , Flores/metabolismo , Gentiana/anatomia & histologia , Tilacoides/metabolismo , Clorofila/metabolismo , Transporte de Elétrons , Japão , Microscopia Eletrônica de Transmissão , Microscopia de Fluorescência , Fotossíntese , Complexo de Proteína do Fotossistema I/metabolismo , Complexo de Proteína do Fotossistema II/metabolismo , Epiderme Vegetal/citologia , Epiderme Vegetal/metabolismo , Folhas de Planta/metabolismo
2.
Proc Natl Acad Sci U S A ; 117(28): 16667-16677, 2020 07 14.
Artigo em Inglês | MEDLINE | ID: mdl-32601177

RESUMO

Plants are known for their outstanding capacity to recover from various wounds and injuries. However, it remains largely unknown how plants sense diverse forms of injury and canalize existing developmental processes into the execution of a correct regenerative response. Auxin, a cardinal plant hormone with morphogen-like properties, has been previously implicated in the recovery from diverse types of wounding and organ loss. Here, through a combination of cellular imaging and in silico modeling, we demonstrate that vascular stem cell death obstructs the polar auxin flux, much alike rocks in a stream, and causes it to accumulate in the endodermis. This in turn grants the endodermal cells the capacity to undergo periclinal cell division to repopulate the vascular stem cell pool. Replenishment of the vasculature by the endodermis depends on the transcription factor ERF115, a wound-inducible regulator of stem cell division. Although not the primary inducer, auxin is required to maintain ERF115 expression. Conversely, ERF115 sensitizes cells to auxin by activating ARF5/MONOPTEROS, an auxin-responsive transcription factor involved in the global auxin response, tissue patterning, and organ formation. Together, the wound-induced auxin accumulation and ERF115 expression grant the endodermal cells stem cell activity. Our work provides a mechanistic model for wound-induced stem cell regeneration in which ERF115 acts as a wound-inducible stem cell organizer that interprets wound-induced auxin maxima.


Assuntos
Proteínas de Arabidopsis/metabolismo , Arabidopsis/fisiologia , Ácidos Indolacéticos/metabolismo , Regeneração , Fatores de Transcrição/metabolismo , Arabidopsis/genética , Proteínas de Arabidopsis/genética , Divisão Celular , Autorrenovação Celular , Regulação da Expressão Gênica de Plantas , Epiderme Vegetal/citologia , Epiderme Vegetal/metabolismo , Reguladores de Crescimento de Planta/metabolismo , Fatores de Transcrição/genética
3.
Science ; 367(6481): 1003-1007, 2020 02 28.
Artigo em Inglês | MEDLINE | ID: mdl-32108107

RESUMO

The process by which plant cells expand and gain shape has presented a challenge for researchers. Current models propose that these processes are driven by turgor pressure acting on the cell wall. Using nanoimaging, we show that the cell wall contains pectin nanofilaments that possess an intrinsic expansion capacity. Additionally, we use growth models containing such structures to show that a complex plant cell shape can derive from chemically induced local and polarized expansion of the pectin nanofilaments without turgor-driven growth. Thus, the plant cell wall, outside of the cell itself, is an active participant in shaping plant cells. Extracellular matrix function may similarly guide cell shape in other kingdoms, including Animalia.


Assuntos
Arabidopsis/embriologia , Pectinas/metabolismo , Pectinas/ultraestrutura , Células Vegetais , Desenvolvimento Vegetal , Epiderme Vegetal/citologia , Arabidopsis/citologia , Forma Celular , Parede Celular/metabolismo , Cotilédone/citologia , Cotilédone/embriologia , Metilação , Imagem Molecular
4.
Planta ; 251(3): 65, 2020 Feb 14.
Artigo em Inglês | MEDLINE | ID: mdl-32060652

RESUMO

MAIN CONCLUSION: Swelling of sweet cherry cell walls is a physical process counterbalanced by turgor. Cell turgor prevents swelling in intact cells, whereas loss of turgor allows cell walls to swell. Swelling of epidermal cell walls precedes skin failure in sweet cherry (Prunus avium) cracking. Swollen cell walls lead to diminished cell:cell adhesions. We identify the mechanism of cell wall swelling. Swelling was quantified microscopically on epidermal sections following freeze/thaw treatment or by determining swelling pressure or swelling capacity of cell wall extracts. Releasing turgor by a freeze/thaw treatment increased cell wall thickness 1.6-fold within 2 h. Pressurizing cell wall extracts at > 12 kPa prevented swelling in water, while releasing the pressure increased swelling. The effect was fully reversible. Across cultivars, cell wall thickness before and after turgor release in two subsequent seasons was significantly correlated (before release of turgor: r = 0.71**, n = 14; after release of turgor: r = 0.73**, n = 14) as was the swelling of cell walls upon turgor release (r = 0.71**, n = 14). Close relationships were also identified for cell wall thickness of fruit of the same cultivars grown in the greenhouse and the field (before release of turgor: r = 0.60, n = 10; after release of turgor: r = 0.78**, n = 10). Release of turgor by heating, plasmolysis, incubation in solvents or surfactants resulted in similar swelling (range 2.0-3.1 µm). Cell wall swelling increased from 1.4 to 3.0 µm as pH increased from pH 2.0 to 5.0 but remained nearly constant between pH 5.0 and 8.0. Increasing ethanol concentration decreased swelling. Swelling of sweet cherry cell walls is a physical process counterbalanced by turgor.


Assuntos
Parede Celular/metabolismo , Frutas/citologia , Prunus avium/citologia , Parede Celular/efeitos dos fármacos , Frutas/efeitos dos fármacos , Sucos de Frutas e Vegetais , Concentração de Íons de Hidrogênio , Osmose , Epiderme Vegetal/citologia , Epiderme Vegetal/efeitos dos fármacos , Polietilenoglicóis/farmacologia , Pressão , Prunus avium/efeitos dos fármacos , Sacarose/farmacologia , Fatores de Tempo
5.
Microsc Res Tech ; 83(5): 541-550, 2020 May.
Artigo em Inglês | MEDLINE | ID: mdl-31981402

RESUMO

Taxonomy of the genus Berberis is quite complex, due to overlapping morphological characters, making it very difficult to differentiate the species within the genus. In order to resolve this taxonomic complexity, the foliar anatomy of 10 Berberis L. species was carried out, for the first time from Pakistan, using light microscopy (LM). Significant variation in terms of epidermal cells shape, size, cell wall pattern, and stomata type was observed. B. baluchistanica has the largest epidermal cells, Adaxial: length = 45-(53.9 ± 3.6)-62.5 µm; and width = 22.5-(26.3 ± 1.3)-30 µm; Abaxial: length = 37.5-(43.25 ± 2.5)-50 µm; and width = 20-(22.6 ± 0.8)-25. The highest number of stomata was observed in B. glaucocarpa as 62 on the abaxial surface while the lowest number of stomata was recorded in B. baluchistanica as 8 on the adaxial surface. Of 10 investigated species, 6 possess anomocytic type stomata, while 2 species that is, B. aitchisonii and B. parkeriana have both anomocytic and anisocytic stomata while B. baluchistanica and B. calliobotrys have only paracytic type stomata. The highest number of cells per unit area was present on the adaxial surface of B. calliobotrys ranging from 245-(252.4)-260 followed by B. parkeriana with 209-(227.8)-250 on the abaxial surface. Stomatal index (SI) also varied considerably and was the lowest (2.6) percentage in B. baluchistanica and highest (31.9) percentage in B. kunawurensis. A taxonomic key based on micro-morphological characters is provided for species identification.


Assuntos
Berberis/anatomia & histologia , Berberis/classificação , Epiderme Vegetal/citologia , Microscopia Eletrônica de Varredura , Paquistão , Epiderme Vegetal/ultraestrutura , Folhas de Planta/citologia , Estômatos de Plantas/ultraestrutura , Tricomas/ultraestrutura
6.
Spectrochim Acta A Mol Biomol Spectrosc ; 224: 117460, 2020 Jan 05.
Artigo em Inglês | MEDLINE | ID: mdl-31422338

RESUMO

Over the past decades, ATR-FTIR has emerged as promising tool for the identification of plants at the genus and (sub-) species level through surface measurements of intact leaves. Theoretical considerations regarding the penetration depth of the evanescent wave into the sample and the thickness of plant leaf cuticles suggest that the structure and composition of the cuticle represent universal taxonomic markers. However, experimental evidence for this hypothesis is scarce. In the current contribution, we present results of a series of simple experiments on epidermal monolayers derived from the bulbs of Allium cepa L. (Amaryllidaceae) as a model system to study the effect of an IR active probe located beyond the theoretical penetration depth of the evanescent wave. We found that this probe had a significant influence on the ATR-FTIR spectra for up to 4 epidermal layers stacked on top of each other corresponding to a total thickness of around 60 µm, exceeding the theoretical penetration depth of the evanescent wave by a factor of around 20. Altogether, our data indicate a major discrepancy between theory and practice in ATR-FTIR spectroscopy in general and provide strong evidence that in general plant leaf spectra cannot be fully explained by the structure and composition of the cuticle alone.


Assuntos
Cebolas , Epiderme Vegetal , Folhas de Planta , Espectroscopia de Infravermelho com Transformada de Fourier/métodos , Cebolas/química , Cebolas/citologia , Epiderme Vegetal/química , Epiderme Vegetal/citologia , Folhas de Planta/química , Folhas de Planta/citologia , Análise de Componente Principal , Microtomografia por Raio-X
7.
Nat Plants ; 5(11): 1145-1153, 2019 11.
Artigo em Inglês | MEDLINE | ID: mdl-31712761

RESUMO

The Arabidopsis genome contains three genes encoding proteins of the TRANSPARENT TESTA GLABRA 1 (TTG1) WD-repeat (WDR) subfamily. TTG1 is a known regulator of epidermal cell differentiation and pigment production, while LIGHT-REGULATED WD1 and LIGHT-REGULATED WD2 are known regulators of the circadian clock. Here, we discovered a new central role for TTG1 WDR proteins as regulators of the circadian system, as evidenced by the lack of detectable circadian rhythms in a triple lwd1 lwd2 ttg1 mutant. This shows that there has been subfunctionalization via protein changes within the angiosperms, with some TTG1 WDR proteins developing a stronger role in circadian clock regulation while losing the protein characteristics essential for pigment production and epidermal cell specification, and others weakening their ability to drive circadian clock regulation. Our work shows that even where proteins are very conserved, small changes can drive big functional differences.


Assuntos
Proteínas de Arabidopsis/fisiologia , Arabidopsis/fisiologia , Pigmentação/fisiologia , Células Vegetais/fisiologia , Epiderme Vegetal/citologia , Arabidopsis/citologia , Diferenciação Celular
8.
Int J Mol Sci ; 20(18)2019 Sep 10.
Artigo em Inglês | MEDLINE | ID: mdl-31509941

RESUMO

Methylation/demethylation of cytosines is an epigenetic strategy for transcriptional regulation, allowing organisms to rapidly respond and adapt to different stimuli. In this context, and using Arabidopsis thaliana as a plant model, we explored whether an environmental stress is sufficient to trigger a change in the methylation status of Glabra-2, a master gene associated with root epidermal cell differentiation. As this gene acts mainly in the epidermis in the root, we examined the stress-driven methylation levels specifically in that tissue. We focused on the stress caused by different salt concentrations in the growth medium. When testing the effect of 20 and 75 mM NaCl, we found that there is a significant decrease in the CG methylation level of the analyzed genomic region within the epidermis. Whereas this reduction was 23% in mildly stressed plants, it turned out to be more robust (33%) in severely stressed ones. Notably, this latter epigenetic change was accompanied by an increase in the number of trichoblasts, the epidermal cell type responsible for root hair development. Analysis of an eventual inheritance of epigenetic marks showed that the non-stressed progeny (F1) of stressed plants did not inherit-in a Lamarckian fashion-the methylation changes that had been acquired by the parental individuals.


Assuntos
Proteínas de Arabidopsis/genética , Arabidopsis/genética , Diferenciação Celular/genética , Metilação de DNA/genética , Proteínas de Homeodomínio/genética , Epiderme Vegetal/genética , Raízes de Plantas/genética , Estresse Salino/genética , Diferenciação Celular/efeitos dos fármacos , Metilação de DNA/efeitos dos fármacos , Epigênese Genética , Epigenômica/métodos , Regulação da Expressão Gênica de Plantas/efeitos dos fármacos , Epiderme Vegetal/citologia , Raízes de Plantas/citologia , Cloreto de Sódio/farmacologia , Estresse Fisiológico/efeitos dos fármacos , Estresse Fisiológico/genética
9.
Int J Mol Sci ; 20(18)2019 Sep 11.
Artigo em Inglês | MEDLINE | ID: mdl-31514406

RESUMO

The quality of alfalfa, a main forage legume worldwide, is of great importance for the dairy industry and is affected by the content of triterpene saponins. These natural terpenoid products of triterpene aglycones are catalyzed by squalene synthase (SQS), a highly conserved enzyme present in eukaryotes. However, there is scare information on alfalfa SQS. Here, an open reading frame (ORF) of SQS was cloned from alfalfa. Sequence analysis showed MsSQS had the same exon/intron composition and shared high homology with its orthologs. Bioinformatic analysis revealed the deduced MsSQS had two transmembrane domains. When transiently expressed, GFP-MsSQS fusion protein was localized on the plasma membrane of onion epidermal cells. Removal of the C-terminal transmembrane domain of MsSQS improved solubility in Escherichia coli. MsSQS was preferably expressed in roots, followed by leaves and stems. MeJA treatment induced MsSQS expression and increased the content of total saponins. Overexpression of MsSQS in alfalfa led to the accumulation of total saponins, suggesting a correlation between MsSQS expression level with saponins content. Therefore, MsSQS is a canonical squalene synthase and contributes to saponin synthesis in alfalfa. This study provides a key candidate gene for genetic manipulation of the synthesis of triterpene saponins, which impact both plant and animal health.


Assuntos
Farnesil-Difosfato Farnesiltransferase/genética , Genes de Plantas , Medicago sativa/enzimologia , Medicago sativa/genética , Acetatos/farmacologia , Sequência de Aminoácidos , Membrana Celular/metabolismo , Clonagem Molecular , Ciclopentanos/farmacologia , Escherichia coli/metabolismo , Éxons/genética , Farnesil-Difosfato Farnesiltransferase/química , Regulação da Expressão Gênica de Plantas/efeitos dos fármacos , Proteínas de Fluorescência Verde/metabolismo , Íntrons/genética , Cebolas/citologia , Oxilipinas/farmacologia , Filogenia , Epiderme Vegetal/citologia , Plantas Geneticamente Modificadas , Domínios Proteicos , Estrutura Secundária de Proteína , Saponinas/metabolismo , Solubilidade
10.
Methods Mol Biol ; 1992: 215-230, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31148041

RESUMO

Cellular force microscopy (CFM) is a noninvasive microindentation method used to measure plant cell stiffness in vivo. CFM is a scanning probe microscopy technique similar in operation to atomic force microscopy (AFM); however, the scale of movement and range of forces are much larger, making it suitable for stiffness measurements on turgid plant cells in whole organs. CFM experiments can be performed on living samples over extended time periods, facilitating the exploration of the dynamics of processes involving mechanics. Different sensor technologies can be used, along with a variety of probe shapes and sizes that can be tailored to specific applications. Measurements can be made for specific indentation depths, forces and timing, allowing for very precise mechanical stimulation of cells with known forces. High forces with sharp tips can also be used for mechanical ablation of cells with force feedback.


Assuntos
Módulo de Elasticidade , Microscopia de Varredura por Sonda/métodos , Cebolas/citologia , Epiderme Vegetal/citologia , Fenômenos Biomecânicos , Parede Celular/química , Desenho de Equipamento , Microscopia de Varredura por Sonda/instrumentação , Cebolas/química , Células Vegetais/química , Epiderme Vegetal/química , Software
11.
Methods Mol Biol ; 1992: 329-349, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31148049

RESUMO

Morphological analysis of cell shapes requires segmentation of cell contours from input images and subsequent extraction of meaningful shape descriptors that provide the basis for qualitative and quantitative assessment of shape characteristics. Here, we describe the publicly available ImageJ plugin PaCeQuant and its associated R package PaCeQuantAna, which provides a pipeline for fully automatic segmentation, feature extraction, statistical analysis, and graphical visualization of cell shape properties. PaCeQuant is specifically well suited for analysis of jigsaw puzzle-like leaf epidermis pavement cells from 2D input images and supports the quantification of global, contour-based, skeleton-based, and pavement cell-specific shape descriptors.


Assuntos
Arabidopsis/citologia , Processamento de Imagem Assistida por Computador/métodos , Microscopia Confocal/métodos , Epiderme Vegetal/citologia , Folhas de Planta/citologia , Arabidopsis/ultraestrutura , Forma Celular , Epiderme Vegetal/ultraestrutura , Folhas de Planta/ultraestrutura , Software
12.
Nat Commun ; 10(1): 1744, 2019 04 15.
Artigo em Inglês | MEDLINE | ID: mdl-30988311

RESUMO

SCM, a leucine-rich repeat receptor-like kinase, is required for root epidermal cells to appropriately interpret their location and generate the proper cell-type pattern during Arabidopsis root development. Here, via a screen for scm-like mutants we describe a new allele of the QKY gene. We find that QKY is required for the appropriate spatial expression of several epidermal cell fate regulators in a similar manner as SCM in roots, and that QKY and SCM are necessary for the efficient movement of CPC between epidermal cells. We also show that turnover of SCM is mediated by a vacuolar degradation pathway triggered by ubiquitination, and that QKY prevents this SCM ubiquitination through their physical interaction. These results suggest that QKY stabilizes SCM through interaction, and this complex facilitates CPC movement between the epidermal cells to help establish the cell-type pattern in the Arabidopsis root epidermis.


Assuntos
Proteínas de Arabidopsis/fisiologia , Arabidopsis/crescimento & desenvolvimento , Arabidopsis/citologia , Arabidopsis/metabolismo , Proteínas de Arabidopsis/genética , Proteínas de Arabidopsis/metabolismo , Morfogênese , Epiderme Vegetal/citologia , Epiderme Vegetal/metabolismo , Raízes de Plantas/citologia , Raízes de Plantas/crescimento & desenvolvimento , Raízes de Plantas/metabolismo , Proteínas Proto-Oncogênicas c-myb/metabolismo , Receptores Proteína Tirosina Quinases/genética , Receptores Proteína Tirosina Quinases/metabolismo , Transdução de Sinais
13.
Microsc Res Tech ; 82(6): 786-802, 2019 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-30801847

RESUMO

Foliar and stem epidermal anatomical features of the tribe Cynoglosseae have been studied in detail for the taxonomic identification using light microscopy (LM) and scanning electron microscopic (SEM) techniques. A comparative study was conducted on different plant parts (leaf and stem epidermal anatomy) of 25 species belonging to eight genera of the tribe Cynoglosseae (Boraginaceae) collected from different phytogeographical regions of Iran for the first time. Different qualitative and quantitative characteristics were observed in detail using LM and SEM. Results showed that although generally the stem and leaf anatomical traits were similar, but some diagnostic features were examined for distinguishing the closely related genera in the tribe. The ratio of cortex/diameter of stem and phloem/xylem, the average row number of collenchyma, palisade and spongy cells, structure of trichomes, type of indumentum and palisade arrangement were found taxonomically important. The anatomical characters were statistically analyzed using cluster analysis and principal component analysis. The study found that stem and leaf eccentrics are variable in the genus but constant within species of the same genus. Most species had typical isobilateral leaves, but some showed an incipient dorsoventrally symmetry with a layer of abaxial palisade tissue. Eglandular trichomes were observed found in all the studied species, which were recognized based on structure and function. In present study some novel characters have been observed which are of great interest to the taxonomist for the correct identification some genera delimitations. The characters studied here are of less taxonomic value and delimitating at species level.


Assuntos
Boraginaceae/anatomia & histologia , Epiderme Vegetal/citologia , Folhas de Planta/anatomia & histologia , Caules de Planta/anatomia & histologia , Biometria , Irã (Geográfico) , Microscopia , Microscopia Eletrônica de Varredura
14.
Plant Physiol ; 180(1): 276-288, 2019 05.
Artigo em Inglês | MEDLINE | ID: mdl-30737268

RESUMO

The Arabidopsis (Arabidopsis thaliana) root epidermis is a simple model for investigating cell fate specification and pattern formation. In addition to regulatory networks consisting of transcription factors, histone deacetylases are also involved in the formation of cellular patterns. Here, we report thatHistone Deacetylase19 (HDA19) affects the root epidermal cellular pattern through regulation of cortical cell fate by interacting with SCARECROW (SCR). HDA19 binds to the DNA sequence upstream of SCR, as well as to those of several of SCR's target genes, and regulates their expression. Mutant lines of several SCR target genes show impaired patterns of epidermal differentiation and cortical cell division, similar to that of hda19 This work presents HDA19 and SCR as two further players in the regulation of cortical and epidermal cell specification and describes an additional function for SCR.


Assuntos
Proteínas de Arabidopsis/metabolismo , Arabidopsis/citologia , Histona Desacetilases/metabolismo , Raízes de Plantas/citologia , Arabidopsis/metabolismo , Proteínas de Arabidopsis/genética , Diferenciação Celular , Regulação da Expressão Gênica de Plantas , Histona Desacetilases/genética , Células Vegetais , Epiderme Vegetal/citologia , Raízes de Plantas/metabolismo , Plantas Geneticamente Modificadas
15.
Development ; 146(4)2019 02 22.
Artigo em Inglês | MEDLINE | ID: mdl-30760483

RESUMO

Cell fate determination in plants relies on positional cues. To investigate the position-dependent gene regulation in plants, we focused on shoot epidermal cell specification, which occurs only in the outermost cells. ATML1, which encodes an HD-ZIP class IV transcription factor, is a positive regulator of shoot epidermal cell identity. Despite the presence of a weak ATML1 promoter activity in the inner cells, ATML1 protein was detected mostly in the outermost cells, which suggests that ATML1 accumulation is inhibited in the inner cells. ATML1 nuclear localization was reduced in the epidermis and there was a positive, albeit weak, correlation between the amount of ATML1 in the nuclei and the expression of a direct target of ATML1. Nuclear accumulation of ATML1 was more strongly inhibited in the inner cells than in the outermost cells. Domain deletion analyses revealed that the ZLZ-coding sequence was necessary and partially sufficient for the post-transcriptional repression of ATML1 Our results suggest that post-transcriptional repressions contribute to the restriction of master transcriptional regulator activity in specific cells to enable position-dependent cell differentiation.


Assuntos
Proteínas de Arabidopsis/metabolismo , Arabidopsis/genética , Regulação da Expressão Gênica de Plantas , Proteínas de Homeodomínio/metabolismo , Processamento Pós-Transcricional do RNA , Arabidopsis/metabolismo , Diferenciação Celular , Linhagem da Célula , Núcleo Celular/metabolismo , Citoplasma/metabolismo , Deleção de Genes , Perfilação da Expressão Gênica , Proteínas de Fluorescência Verde/metabolismo , Mutação , Sinais de Localização Nuclear , Epiderme Vegetal/citologia , Plantas Geneticamente Modificadas/metabolismo , Regiões Promotoras Genéticas , Domínios Proteicos , Transcrição Genética
16.
Microsc Res Tech ; 82(6): 764-774, 2019 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-30762920

RESUMO

Iris L. is one of the important genus of family Iridaceae, consist of 56 taxa naturally occurred in Turkey. The similarities and variations in the subgenus overlapping the taxonomic positions of the species in the subgenera and needs anatomical assessment especially by microscopic techniques. In this study, the taxonomic significance of leaf anatomical characters of 10 Iris subgenus Scorpiris taxa were studied in detail and the relationship among these taxa were evaluated using microscopy techniques. Fresh leaf samples of species were fixed in 70% alcohol solution for anatomical observation under microscope. Eleven different micromorphological features were statistically analyzed to delimit the species in subgenus. Based on morphological and anatomical similarities, we studied relationships among; (1) ssp. turcica, ssp. caucasica, I. nezahatiae and I. pseudocaucasica; (2) correlation between ssp. turcica and ssp. caucasica; (3) association of I. galatica, I. persica, ssp. margaretiae and ssp. stenophylla with each other; (4) relationship between ssp. stenophylla and ssp. margaretiae; and (5) relevance between I. aucheri and I. peshmeniana. Moreover, the taxonomy of subgenus Scorpiris has been discussed in detail with novel and diagnostic features based on micromorphological physiognomies. We found that four species in this study are endemic to Turkey, while seven are critically endangered geophytes in the country. The leaf anatomical characteristics of 10 taxa were divided into three groups. Main aim of this research was to study the taxonomy of the complex subgenus Scorpiris through microscopic techniques.


Assuntos
Iridaceae/anatomia & histologia , Iridaceae/classificação , Epiderme Vegetal/citologia , Folhas de Planta/anatomia & histologia , Microscopia , Turquia
17.
PLoS One ; 14(1): e0210141, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-30682033

RESUMO

Plant leaves occur in diverse shapes. Divarication patterns that develop during early growths are one of key factors that determine leaf shapes. We utilized leaves of Microsorum pteropus, a semi-aquatic fern, and closely related varieties to analyze a variation in the divarication patterns. The leaves exhibited three major types of divarication: no lobes, bifurcation, and trifurcation (i.e., monopodial branching). Our investigation of their developmental processes, using time-lapse imaging, revealed localized growths and dissections of blades near each leaf apex. Restricted cell divisions responsible for the apical growths were confirmed using a pulse-chase strategy for EdU labeling assays.


Assuntos
Epiderme Vegetal/citologia , Folhas de Planta/crescimento & desenvolvimento , Polypodiaceae/crescimento & desenvolvimento , Divisão Celular/fisiologia , Folhas de Planta/citologia
18.
Microsc Res Tech ; 82(3): 206-223, 2019 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-30633436

RESUMO

Foliar epidermal features were based on the micromorphology of trichomes types, epidermal cells and stomatal complex. Even though each feature has its own limited taxonomic value but collectively these characteristics may be systematically important especially for the discrimination and identification of complex and problematic taxa. The systematics significance of nonglandular (NGTs) and glandular trichomes (GTs), stomatal complex and epidermal cells of Lamiaceous flora were analyzed by using the light microscopy (LM) and scanning electron microscopy (SEM). Variations on the observed epidermal appendages were divided into two basic types: glandular and nonglandular. GTs can be divided into subtypes: sessile capitate, subsessile capitate, and barrel and sunken. NGTs were also divided into subtypes: dendritic, stellate, conical, falcate, simple and 1-6 cells long having granulate and smooth surface ornamentation. NGTs were the most dominant features of both adaxial and abaxial surfaces of all observed taxa. Vitex negundo, Isodon rugosus, Colebrookea oppositifolia, and Marrubium vulgare could be demarked because of their twisted like appearance of NGTs at the abaxial surface. The Lamiaceae had both hypostomatic and amphistomatic leaf. Stomata were observed as diacytic, anisocytic, and anomocytic. Epidermal cells were found to be irregular, isodiametric, and rectangular. Based on these characters a taxonomic key was developed to delimit the closely related taxa. Distribution and morphology of the foliar epidermal trichomes through SEM highlight an important taxonomic tool used by the taxonomists as an aid to the correct identification of problematic Lamiaceae taxa.


Assuntos
Lamiaceae/anatomia & histologia , Epiderme Vegetal/citologia , Folhas de Planta/citologia , Estômatos de Plantas/anatomia & histologia , Tricomas/anatomia & histologia , Lamiaceae/classificação , Microscopia Eletrônica de Varredura , Paquistão
19.
J Exp Bot ; 70(2): 529-543, 2019 01 07.
Artigo em Inglês | MEDLINE | ID: mdl-30407556

RESUMO

Plant microtubules form a highly dynamic intracellular network with important roles for regulating cell division, cell proliferation, and cell morphology. Their organization and dynamics are co-ordinated by various microtubule-associated proteins (MAPs) that integrate environmental and developmental stimuli to fine-tune and adjust cytoskeletal arrays. IQ67 DOMAIN (IQD) proteins recently emerged as a class of plant-specific MAPs with largely unknown functions. Here, using a reverse genetics approach, we characterize Arabidopsis IQD5 in terms of its expression domains, subcellular localization, and biological functions. We show that IQD5 is expressed mostly in vegetative tissues, where it localizes to cortical microtubule arrays. Our phenotypic analysis of iqd5 loss-of-function lines reveals functions of IQD5 in pavement cell (PC) shape morphogenesis. Histochemical analysis of cell wall composition further suggests reduced rates of cellulose deposition in anticlinal cell walls, which correlate with reduced anisotropic expansion. Lastly, we demonstrate IQD5-dependent recruitment of calmodulin calcium sensors to cortical microtubule arrays and provide first evidence for important roles for calcium in regulation of PC morphogenesis. Our work identifies IQD5 as a novel player in PC shape regulation and, for the first time, links calcium signaling to developmental processes that regulate anisotropic growth in PCs.


Assuntos
Proteínas de Arabidopsis/metabolismo , Arabidopsis/metabolismo , Proteínas de Membrana/metabolismo , Proteínas Associadas aos Microtúbulos/metabolismo , Epiderme Vegetal/crescimento & desenvolvimento , Folhas de Planta/crescimento & desenvolvimento , Arabidopsis/citologia , Arabidopsis/crescimento & desenvolvimento , Sinalização do Cálcio , Calmodulina/metabolismo , Celulose/metabolismo , Cotilédone/crescimento & desenvolvimento , Desenvolvimento Embrionário , Microtúbulos/metabolismo , Epiderme Vegetal/citologia , Folhas de Planta/citologia
20.
New Phytol ; 221(1): 540-552, 2019 01.
Artigo em Inglês | MEDLINE | ID: mdl-30281798

RESUMO

Epidermal cells of leaves are diverse: tabular pavement cells, trichomes, and stomatal complexes. Pavement cells from the monocot Zea mays (maize) and the eudicot Arabidopsis thaliana (Arabidopsis) have highly undulate anticlinal walls. The molecular basis for generating these undulating margins has been extensively investigated in these species. This has led to two assumptions: first, that particular plant lineages are characterized by particular pavement cell shapes; and second, that undulatory cell shapes are common enough to be model shapes. To test these assumptions, we quantified pavement cell shape in epidermides from the leaves of 278 vascular plant taxa. We found that monocot pavement cells tended to have weakly undulating margins, fern cells had strongly undulating margins, and eudicot cells showed no particular undulation degree. Cells with highly undulating margins, like those of Arabidopsis and maize, were in the minority. We also found a trend towards more undulating cell margins on abaxial leaf surfaces; and that highly elongated leaves in ferns, monocots and gymnosperms tended to have highly elongated cells. Our results reveal the diversity of pavement cell shapes, and lays the quantitative groundwork for testing hypotheses about pavement cell form and function within a phylogenetic context.


Assuntos
Filogenia , Células Vegetais , Folhas de Planta/citologia , Anisotropia , Forma Celular , Processamento de Imagem Assistida por Computador , Epiderme Vegetal/citologia , Plantas/genética
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