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1.
Nat Commun ; 12(1): 458, 2021 01 19.
Artigo em Inglês | MEDLINE | ID: mdl-33469016

RESUMO

Cell shape is crucial for the function and development of organisms. Yet, versatile frameworks for cell shape quantification, comparison, and classification remain underdeveloped. Here, we introduce a visibility graph representation of shapes that facilitates network-driven characterization and analyses across shapes encountered in different domains. Using the example of complex shape of leaf pavement cells, we show that our framework accurately quantifies cell protrusions and invaginations and provides additional functionality in comparison to the contending approaches. We further show that structural properties of the visibility graphs can be used to quantify pavement cell shape complexity and allow for classification of plants into their respective phylogenetic clades. Therefore, the visibility graphs provide a robust and unique framework to accurately quantify and classify the shape of different objects.


Assuntos
Forma Celular , Processamento de Imagem Assistida por Computador/métodos , Folhas de Planta/citologia , Algoritmos , Arabidopsis/citologia , Microscopia/métodos , Software
2.
J Biosci Bioeng ; 130(5): 520-524, 2020 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-32830038

RESUMO

To clarify the physiological factors associated with the development of tomato leaf marginal necrosis associated with potassium deficiency, tomato leaf blades prior to development of the symptoms were collected, and profiles of water-soluble metabolites were analyzed using gas chromatography-mass spectrometry. Multivariate analysis was conducted to screen for a component that was related to potassium deficiency-induced leaf necrosis among the 60 metabolites detected in tomato leaves. Polyamines, sugars, and branched amino acids were ranked highly. Putrescine was most strongly and negatively correlated with potassium concentration and exhibited an exponential response, regardless of the site or plant body. In addition to putrescine, glucose, xylose and l-isoleucine are known to play important roles in stress response and ion balance control, and it is thought that changes in metabolite profiles are linked to tomato leaf marginal necrosis associated with a decrease in endogenous potassium concentration. These findings will be useful for cultivation management to mitigate this physiological disorder of tomato.


Assuntos
Cromatografia Gasosa-Espectrometria de Massas , Lycopersicon esculentum/citologia , Lycopersicon esculentum/metabolismo , Metabolômica , Folhas de Planta/citologia , Folhas de Planta/metabolismo , Potássio/metabolismo , Necrose/metabolismo
3.
Plant Mol Biol ; 104(3): 249-261, 2020 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-32715397

RESUMO

Secondary cell wall not only provides rigidity and mechanical resistance to plants, but also has a large impact on plant growth and adaptation to environments. Biosynthesis of secondary cell wall is regulated by a complicated signaling transduction network; however, it is still unclear how the transcriptional regulation of secondary cell wall biosynthesis works at the molecular level. Here, we report in rice that OVATE family proteins 6 (OsOFP6) is a positive regulator in modulating expression of the genes related to biosynthesis of the secondary cell wall. Transgenic plants with knock-down of OsOFP6 by RNA interference showed increased leaf angle, which resulted from the thinner secondary cell wall with reduced amounts of cellulose and lignin, whilst overexpression of OsOFP6 in rice led to the thinker secondary cell wall with increased lignin content. Protein-protein interaction analysis revealed that OsOFP6 interacts with Oryza sativa homeobox 15 (OSH15), a class I KNOX protein. The interaction of OsOFP6 and OSH15 enhanced the transcriptional activity of OSH15 which binds to the promoter of OsIRX9 (Oryza sativa IRREGULAR XYLEM 9). Taken together, our study provides insights into the function of OsOFP6 in regulating leaf angle and the control of biosynthesis of secondary cell wall.


Assuntos
Parede Celular/metabolismo , Oryza/metabolismo , Folhas de Planta/metabolismo , Proteínas de Plantas/metabolismo , Proteínas Repressoras/metabolismo , Fatores de Transcrição/metabolismo , Arabidopsis/genética , Proteínas de Arabidopsis/genética , Parede Celular/ultraestrutura , Celulose/metabolismo , Regulação da Expressão Gênica de Plantas , Proteínas de Homeodomínio/metabolismo , Lignina/metabolismo , Oryza/genética , Folhas de Planta/anatomia & histologia , Folhas de Planta/citologia , Proteínas de Plantas/genética , Plantas Geneticamente Modificadas/genética , Regiões Promotoras Genéticas , Domínios e Motivos de Interação entre Proteínas , Interferência de RNA , Proteínas Repressoras/genética , Fatores de Transcrição/genética , Xilema/metabolismo
4.
PLoS Genet ; 16(6): e1008873, 2020 06.
Artigo em Inglês | MEDLINE | ID: mdl-32584819

RESUMO

The regulation of leaf size has been studied for decades. Enhancement of post-mitotic cell expansion triggered by impaired cell proliferation in Arabidopsis is an important process for leaf size regulation, and is known as compensation. This suggests a key interaction between cell proliferation and cell expansion during leaf development. Several studies have highlighted the impact of this integration mechanism on leaf size determination; however, the molecular basis of compensation remains largely unknown. Previously, we identified extra-small sisters (xs) mutants which can suppress compensated cell enlargement (CCE) via a specific defect in cell expansion within the compensation-exhibiting mutant, angustifolia3 (an3). Here we revealed that one of the xs mutants, namely xs2, can suppress CCE not only in an3 but also in other compensation-exhibiting mutants erecta (er) and fugu2. Molecular cloning of XS2 identified a deleterious mutation in CATION CALCIUM EXCHANGER 4 (CCX4). Phytohormone measurement and expression analysis revealed that xs2 shows hyper activation of the salicylic acid (SA) response pathway, where activation of SA response can suppress CCE in compensation mutants. All together, these results highlight the regulatory connection which coordinates compensation and SA response.


Assuntos
Antiporters/genética , Proteínas de Arabidopsis/metabolismo , Arabidopsis/fisiologia , Reguladores de Crescimento de Planta/metabolismo , Folhas de Planta/crescimento & desenvolvimento , Ácido Salicílico/metabolismo , Proteínas de Arabidopsis/genética , Cálcio/metabolismo , Cátions Bivalentes/metabolismo , Crescimento Celular , Proliferação de Células/genética , Regulação da Expressão Gênica de Plantas , Mutação com Perda de Função , Tamanho do Órgão/genética , Folhas de Planta/citologia , Folhas de Planta/metabolismo , Plantas Geneticamente Modificadas , Transdução de Sinais/genética
5.
Plant Mol Biol ; 103(4-5): 527-543, 2020 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-32323129

RESUMO

KEY MESSAGE: Two homologous, chloroplast located CAAX proteases were identified to be functional redundancy in determining soybean leaf color, and they probably play essential roles in regulating light harvesting and absorption during photosynthesis process. Leaf color mutants are ideal materials for studying photosynthesis and chlorophyll metabolism. The soybean [Glycine max (L.) Merr.] yellowing leaf (yl) variation is a recombinant mutant characterized by yellow foliage, which derived from the specific cross between green seed-coated and yellow seed-coated soybean varieties. Molecular cloning and subsequent gene silencing revealed that the yellow leaf trait of yl was controlled by two recessive nuclear genes, glyma11g04660 and glyma01g40650, named as YL1 and YL2 respectively, and the latter was confirmed to be same as the earlier reported green seed-coat gene G. Both YL1 and YL2 belonged to chloroplast-located proteases possessing Abi domain, and these genes were expressed in various tissues, especially in young leaves. In yl, the expression of YL1 and YL2 were suppressed in most tissues, and the young leaf of yl presented an increased maximal photochemical efficiency (Fv/Fm) as well as enhanced net photosynthesis activity (Pn), indicating that YL1 and YL2 are involved in light absorption regulation during photosynthesis process. Collectively, the identification and description of YL1 and YL2 in our study provides insights for the regulatory mechanism of photosynthesis process, and these findings will further assist to clarify the close relationship between photosynthesis and chlorophyll metabolism.


Assuntos
Genes de Plantas/genética , Mutação , Fenótipo , Folhas de Planta/genética , Proteínas de Plantas/genética , Soja/genética , Alelos , Sequência de Bases , Clorofila/genética , Clorofila/metabolismo , Clonagem Molecular , Cor , Regulação da Expressão Gênica de Plantas , Técnicas de Silenciamento de Genes , Inativação Gênica , Fotossíntese/genética , Fotossíntese/fisiologia , Pigmentos Biológicos/análise , Folhas de Planta/citologia , Proteínas de Plantas/metabolismo , Sementes/citologia , Alinhamento de Sequência , Análise de Sequência de Proteína
6.
Plant Mol Biol ; 103(3): 321-340, 2020 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-32277429

RESUMO

Plants live in constantly changing and often unfavorable or stressful environments. Environmental changes induce biotic and abiotic stress, which, in turn, may cause genomic DNA damage. Hence, plants simultaneously suffer abiotic/biotic stress and DNA damage. However, little information is available on the signaling crosstalk that occurs between DNA damage and abiotic/biotic stresses. Arabidopsis thaliana SUPPRESSOR OF GAMMA RESPONSE1 (SOG1) is a pivotal transcription factor that regulates thousands of genes in response to DNA double-strand break (DSB), and we recently reported that SOG1 has a role in immune responses. In the present study, the effects of SOG1 overexpression on the DNA damage and immune responses were examined. Results found that SOG1 overexpression enhances the regulation of numerous downstream genes. Relative to the wild type plants, then, DNA damage responses were observed to be strongly induced. SOG1 overexpression also upregulates chitin (a major components of fungal cell walls) responsive genes in the presence of DSBs, implying that pathogen defense response is activated by DNA damage via SOG1. Further, SOG1 overexpression enhances fungal resistance. These results suggest that SOG1 regulates crosstalk between DNA damage response and the immune response and that plants have evolved a sophisticated defense network to contend with environmental stress.


Assuntos
Proteínas de Arabidopsis/metabolismo , Arabidopsis/metabolismo , Dano ao DNA/fisiologia , Regulação da Expressão Gênica de Plantas/fisiologia , Fatores de Transcrição/metabolismo , Apoptose/fisiologia , Arabidopsis/genética , Proteínas de Arabidopsis/genética , Sequência de Bases , DNA de Plantas , Regulação da Expressão Gênica de Plantas/imunologia , Folhas de Planta/citologia , Ligação Proteica , Estresse Fisiológico , Fatores de Transcrição/genética
7.
J Plant Res ; 133(3): 311-321, 2020 May.
Artigo em Inglês | MEDLINE | ID: mdl-32206925

RESUMO

Bryophytes and vascular plants represent the broadest evolutionary divergence in the land plant lineage, and comparative analyses of development spanning this divergence therefore offer opportunities to identify truisms of plant development in general. In vascular plants, organs are formed repetitively around meristems at the growing tips in response to positional cues. In contrast, leaf formation in mosses and leafy liverworts occurs from clonal groups of cells derived from a daughter cell of the apical stem cell known as merophytes, and cell lineage is a crucial factor in repetitive organ formation. However, it remains unclear whether merophyte lineages are a general feature of repetitive organ formation in bryophytes as patterns of organogenesis in thalloid liverworts are unclear. To address this question, we developed a clonal analysis method for use in the thalloid liverwort Marchantia polymorpha, involving random low-frequency induction of a constitutively expressed nuclear-targeted fluorescent protein by dual heat-shock and dexamethasone treatment. M. polymorpha thalli ultimately derive from stem cells in the apical notch, and the lobes predominantly develop from merophytes cleft to the left and right of the apical cell(s). Sector induction in gemmae and subsequent culture occasionally generated fluorescent sectors that bisected thalli along the midrib and were maintained through several bifurcation events, likely reflecting the border between lateral merophytes. Such thallus-bisecting sectors traversed dorsal air chambers and gemma cups, suggesting that these organs arise independently of merophyte cell lineages in response to local positional cues.


Assuntos
Marchantia/crescimento & desenvolvimento , Organogênese Vegetal , Folhas de Planta/citologia
8.
Nat Commun ; 11(1): 1460, 2020 03 19.
Artigo em Inglês | MEDLINE | ID: mdl-32193383

RESUMO

Since the discovery of quantum beats in the two-dimensional electronic spectra of photosynthetic pigment-protein complexes over a decade ago, the origin and mechanistic function of these beats in photosynthetic light-harvesting has been extensively debated. The current consensus is that these long-lived oscillatory features likely result from electronic-vibrational mixing, however, it remains uncertain if such mixing significantly influences energy transport. Here, we examine the interplay between the electronic and nuclear degrees of freedom (DoF) during the excitation energy transfer (EET) dynamics of light-harvesting complex II (LHCII) with two-dimensional electronic-vibrational spectroscopy. Particularly, we show the involvement of the nuclear DoF during EET through the participation of higher-lying vibronic chlorophyll states and assign observed oscillatory features to specific EET pathways, demonstrating a significant step in mapping evolution from energy to physical space. These frequencies correspond to known vibrational modes of chlorophyll, suggesting that electronic-vibrational mixing facilitates rapid EET over moderately size energy gaps.


Assuntos
Transferência de Energia , Complexos de Proteínas Captadores de Luz/química , Teoria Quântica , Elétrons , Complexos de Proteínas Captadores de Luz/metabolismo , Modelos Químicos , Folhas de Planta/citologia , Análise Espectral , Tilacoides/metabolismo
9.
Sci Rep ; 10(1): 4328, 2020 03 09.
Artigo em Inglês | MEDLINE | ID: mdl-32152443

RESUMO

In biology, structure is the basis of function. For plants, changes in their physiological and ecological functions are usually caused by structural changes. To understand how shading conditions change the plant structures, thereby providing structural insights into the improved yield and quality, oilseed tree peony were shaded with different densities of polyethylene nets from 28 days after pollination (DAP) until harvesting. The thickness of the leaf (LT), vein (VT), upper epidermis (UET), lower epidermis (LET), palisade tissue (PT), sponge tissue (ST), as well as the accumulation and distribution of starch, protein, and fat, were observed at 14-day intervals. The results showed that shading had a significant effect on the anatomical structure of the leaves. In the rapid growth period (before 70 DAP), the LT, ET, and VT under shading were significantly lower than under non-shading. During this period, the accumulation of starch and protein under shading was lower than that under non-shading. At the maturation period (99-112 DAP), the LT and PT under shading were higher than under non-shading, indicating that light shading delayed leaf senescence and increased photosynthetic capacity. Shading delayed the degradation of the integument cells and prolonged seed development and nutrient accumulation.


Assuntos
Paeonia/citologia , Paeonia/efeitos da radiação , Folhas de Planta/citologia , Fenômenos Fisiológicos Vegetais , Sementes/citologia , Luz Solar , Biomarcadores , Células Epidérmicas/citologia , Células Epidérmicas/ultraestrutura , Histocitoquímica , Paeonia/metabolismo , Fenótipo , Fotossíntese , Folhas de Planta/anatomia & histologia , Folhas de Planta/metabolismo , Sementes/anatomia & histologia , Sementes/metabolismo , Estresse Fisiológico
10.
Plant Mol Biol ; 102(6): 589-602, 2020 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-32026326

RESUMO

Leaf angle is a key factor in plant architecture and crop yield. Brassinosteroids (BRs) regulate many developmental processes, especially the leaf angle in monocots. However, the BR signalling pathway is complex and includes many unknown members. Here, we propose that Oryza sativa BRASSINOSTEROID-RESPONSIVE LEAF ANGLE REGULATOR 1 (OsBLR1) encodes a bHLH transcription factor, and positively regulates BR signalling to increase the leaf angle and grain length in rice (Oryza sativa L.). Lines overexpressing OsBLR1 (blr1-D and BLR1-OE-1/2/3) had similar traits, with increased leaf angle and grain length. Conversely, OsBLR1-knockout mutants (blr1-1/2/3) had erect leaves and shorter grains. Lamina joint inclination, coleoptile elongation, and root elongation assay results indicated that these overexpression lines were more sensitive to BR, while the knockout mutants were less sensitive. There was no significant difference in the endogenous BR contents of blr1-1/2 and wild-type plants. These results suggest that OsBLR1 is involved in BR signal transduction. The blr1-D mutant, with increased cell growth in the lamina joint and smaller leaf midrib, showed significant changes in gene expression related to the cell wall and leaf development compared with wild-type plants; furthermore, the cellulose and protopectin contents in blr1-D were reduced, which resulted in the increased leaf angle and bent leaves. As the potential downstream target gene of OsBLR1, the REGULATOR OF LEAF INCLINATION1 (OsRLI1) gene expression was up-regulated in OsBLR1-overexpression lines and down-regulated in OsBLR1-knockout mutants. Moreover, we screened OsRACK1A as an interaction protein of OsBLR1 using a yeast two-hybrid assay and glutathione-S-transferase pull-down.


Assuntos
Fatores de Transcrição Hélice-Alça-Hélice Básicos/genética , Fatores de Transcrição Hélice-Alça-Hélice Básicos/metabolismo , Brassinosteroides/metabolismo , Oryza/genética , Oryza/metabolismo , Folhas de Planta/anatomia & histologia , Folhas de Planta/genética , Transdução de Sinais , Regulação da Expressão Gênica de Plantas , Técnicas de Inativação de Genes , Genes de Plantas , Oryza/crescimento & desenvolvimento , Fenótipo , Reguladores de Crescimento de Planta/metabolismo , Folhas de Planta/citologia , Folhas de Planta/crescimento & desenvolvimento , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Plantas Geneticamente Modificadas , Transdução de Sinais/genética , Fatores de Transcrição
11.
J Photochem Photobiol B ; 204: 111819, 2020 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-32062388

RESUMO

Solanum aculeatissimum Jacq. is a common plant in much of Brazil. Despite containing metabolites with a wide range of pharmacological applications, there are few tissue culture reports for this plant. The possibility of large-scale in vitro production of this material has significant biotechnological potential. Therefore, the objective of this study was to investigate the effect of light conditions on the growth of cells in suspension, observing the production and yield of biomass and bioactive compounds and the enzymatic behavior. Calli obtained from leaf segments were cultured in solid medium supplemented with 1 mg L-1 of 2,4-D, 2.5 mg L-1 kinetin, pH 5.7, in the dark. After 110 days of subculture, the calli were transferred to liquid medium. Cells were kept in the dark under agitation at 110 rpm and 25 °C and subcultured every 30 days. After 90 days of culture, 20 mL aliquots of cell suspension were added to flasks containing approximately 20 mL of medium (1:1) and cultured at different wavelengths (white, green, blue, red, and blue/red) under a photoperiod of 16 h with irradiance of 50 µmol m-2 s-1) and in the absence of light. The experiment was performed in a 6 × 6 factorial design (light condition × culture time). The cell cultures showed viability throughout the entire cycle, and chlorogenic and ferulic acids, orientin, quercitrin and, in higher amounts, quercetin, were detected in the first 7 days of culture. There was an increase in superoxide dismutase and catalase and a decrease in ascorbate peroxidase after exposure to different light conditions; for phenylalanine ammonia lyase, no differences were observed. The different light conditions were not sufficient to trigger responses in the concentrations of bioactive compounds, despite the detection of increased levels of the enzymes involved in cellular homeostasis.


Assuntos
Luz , Solanum/metabolismo , Catalase/metabolismo , Técnicas de Cultura de Células , Ácido Clorogênico/metabolismo , Condutividade Elétrica , Flavonoides/metabolismo , Glucosídeos/metabolismo , Concentração de Íons de Hidrogênio , Células Vegetais/metabolismo , Células Vegetais/efeitos da radiação , Folhas de Planta/citologia , Folhas de Planta/metabolismo , Quercetina/análogos & derivados , Quercetina/metabolismo , Solanum/citologia , Superóxido Dismutase/metabolismo
12.
BMC Plant Biol ; 20(1): 17, 2020 Jan 09.
Artigo em Inglês | MEDLINE | ID: mdl-31918680

RESUMO

BACKGROUND: Maize bsd2 (bundle sheath defective2) is a classical C4 mutant with defective C4 photosynthesis, accompanied with reduced accumulation of Rubisco (ribulose bisphosphate carboxylase oxygenase) and aberrant mature chloroplast morphology in the bundle sheath (BS) cells. However, as a hypothetical chloroplast chaperone, the effects of BSD2 on C4 chloroplast development have not been fully examined yet, which precludes a full appreciation of BSD2 function in C4 photosynthesis. The aims of our study are to find out the role ofBSD2 in regulating chloroplasts development in maize leaves, and to add new insights into our understanding of C4 biology. RESULTS: We found that at the chloroplast maturation stage, the thylakoid membranes of chloroplasts in the BS and mesophyll (M) cells became significantly looser, and the granaof chloroplasts in the M cells became thinner stacking in the bsd2 mutant when compared with the wildtype plant. Moreover, at the early chloroplast development stage, the number of dividing chloroplasts and the chloroplast division rate are both reduced in the bsd2 mutant, compared with wild type. Quantitative reverse transcriptase-PCR analysis revealed that the expression of both thylakoid formation-related genesand chloroplast division-related genes is significantly reduced in the bsd2 mutants. Further, we showed that BSD2 interacts physically with the large submit of Rubisco (LS) in Bimolecular Fluorescence Complementation assay. CONCLUSIONS: Our combined results suggest that BSD2 plays an essential role in regulating the division and differentiation of the dimorphic BS and M chloroplasts, and that it acts at a post-transcriptional level to regulate LS stability or assembly of Rubisco.


Assuntos
Cloroplastos/ultraestrutura , Folhas de Planta/citologia , Proteínas de Plantas/genética , Zea mays , Cloroplastos/metabolismo , Mutação , Folhas de Planta/metabolismo , Proteínas de Plantas/metabolismo , Ribulose-Bifosfato Carboxilase/metabolismo , Zea mays/citologia , Zea mays/genética , Zea mays/metabolismo , Zea mays/ultraestrutura
13.
Plant Cell Physiol ; 61(2): 255-264, 2020 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-31922574

RESUMO

Stem cells undergo cell division and differentiation to ensure organized tissue development. Because plant cells are immobile, plant stem cells ought to decide their cell fate prior to differentiation, to locate specialized cells in the correct position. In this study, based on a chemical screen, we isolated a novel secondary cell wall indicator BF-170, which binds to lignin and can be used to image in vitro and in situ xylem development. Use of BF-170 to observe the vascular differentiation pattern in the in vitro vascular cell induction system, VISUAL, revealed that adaxial mesophyll cells of cotyledons predominantly generate ectopic xylem cells. Moreover, phloem cells are abundantly produced on the abaxial layer, suggesting the involvement of leaf adaxial-abaxial polarity in determining vascular cell fate. Analysis of abaxial polarity mutants highlighted the role of YAB3, an abaxial cell fate regulator, in suppressing xylem and promoting phloem differentiation on the abaxial domains in VISUAL. Furthermore, YABBY family genes affected in vivo vascular development during the secondary growth. Our results denoted the possibility that such mediators of spatial information contribute to correctly determine the cell fate of vascular stem cells, to conserve the vascular pattern of land plants.


Assuntos
Diferenciação Celular/fisiologia , Imagem Óptica/métodos , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Células-Tronco/metabolismo , Compostos de Anilina , Arabidopsis/citologia , Arabidopsis/genética , Parede Celular , Cotilédone/citologia , Cotilédone/genética , Cotilédone/crescimento & desenvolvimento , Cotilédone/metabolismo , Corantes Fluorescentes , Genes de Plantas , Lignina/metabolismo , Floema/citologia , Floema/genética , Floema/crescimento & desenvolvimento , Folhas de Planta/citologia , Raízes de Plantas/citologia , Quinolinas , Xilema/citologia , Xilema/genética , Xilema/crescimento & desenvolvimento
14.
BMC Plant Biol ; 20(1): 9, 2020 Jan 06.
Artigo em Inglês | MEDLINE | ID: mdl-31906853

RESUMO

BACKGROUND: Zygophyllum is an important medicinal plant, with notable properties such as resistance to salt, alkali, and drought, as well as tolerance of poor soils and shifting sand. However, the response mechanism of Zygophyllum spp. to abiotic stess were rarely studied. RESULTS: Here, we aimed to explore the salt-tolerance genes of Zygophyllum plants by transcriptomic and metabolic approaches. We chose Z. brachypterum, Z. obliquum and Z. fabago to screen for salt tolerant and sensitive species. Cytological observation showed that both the stem and leaf of Z. brachypterum were significantly thicker than those of Z. fabago. Then, we treated these three species with different concentrations of NaCl, and found that Z. brachypterum exhibited the highest salt tolerance (ST), while Z. fabago was the most sensitive to salt (SS). With the increase of salt concentration, the CAT, SOD and POD activity, as well as proline and chlorophyll content in SS decreased significantly more than in ST. After salt treatment, the proportion of open stomata in ST decreased significantly more than in SS, although there was no significant difference in stomatal number between the two species. Transcriptomic analysis identified a total of 11 overlapping differentially expressed genes (DEGs) in the leaves and roots of the ST and SS species after salt stress. Two branched-chain-amino-acid aminotransferase (BCAT) genes among the 11 DEGs, which were significantly enriched in pantothenate and CoA biosynthesis, as well as the valine, leucine and isoleucine biosynthesis pathways, were confirmed to be significantly induced by salt stress through qRT-PCR. Furthermore, overlapping differentially abundant metabolites showed that the pantothenate and CoA biosynthesis pathways were significantly enriched after salt stress, which was consistent with the KEGG pathways enriched according to transcriptomics. CONCLUSIONS: In our study, transcriptomic and metabolomic analysis revealed that BCAT genes may affect the pantothenate and CoA biosynthesis pathway to regulate the salt tolerance of Zygophyllum species, which may constitute a newly identified signaling pathway through which plants respond to salt stress.


Assuntos
Coenzima A/metabolismo , Metaboloma/genética , Tolerância ao Sal/genética , Transcriptoma/genética , Zygophyllum , Coenzima A/genética , Perfilação da Expressão Gênica , Genes de Plantas , Fosfotransferases (Aceptor do Grupo Álcool)/genética , Folhas de Planta/citologia , Folhas de Planta/metabolismo , Proteínas de Plantas/genética , Raízes de Plantas/citologia , Raízes de Plantas/metabolismo , Estômatos de Plantas/citologia , Estômatos de Plantas/ultraestrutura , Transdução de Sinais/genética , Transaminases/genética , Transaminases/metabolismo , Zygophyllum/anatomia & histologia , Zygophyllum/genética , Zygophyllum/metabolismo
15.
Microsc Res Tech ; 83(5): 558-561, 2020 May.
Artigo em Inglês | MEDLINE | ID: mdl-31967366

RESUMO

This study aimed to determine the influence of auto-exhaust pollution on trichome structure of Olea europea L. leaves. For this purpose, olive leaves were collected from two areas one of which is urban and the other is rural. Leaf surface sections in leaves were obtained to examine the influence of auto-exhaust pollution on trichome structure of olive. Width-length thicknesses in peltate trichome were measured using a micrometric ocular. To investigate the density and the percentages of damaged-nondamaged peltate trichomes among the groups, the upper epidermis of leaves was photographed with SEM. According to the results, the values of width and length thicknesses of peltate trichome were lower in urban area when compared to rural site. The density and percentages of nondamaged peltate structure were lower in urban area whereas damaged peltate structures were increased. Auto-exhaust pollution decreased the amount of nondamaged peltate trichome structure and caused damaged peltate structures in olive leaves. The plant can be more sensitive to drought because of decreased amount of peltate trichomes and also increased damaged peltate trichome structures in urban area.


Assuntos
Poluição do Ar , Olea/anatomia & histologia , Folhas de Planta/citologia , Tricomas/ultraestrutura , Emissões de Veículos , Folhas de Planta/anatomia & histologia , Tricomas/citologia
16.
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
17.
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
18.
Environ Geochem Health ; 42(1): 45-58, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-30874936

RESUMO

Effects of Cu toxicity from contaminated soil were analysed in spring barley (Hordeum sativum distichum), a widely cultivated species in South Russia. In this study, H. sativum was planted outdoors in one of the most fertile soils-Haplic Chernozem spiked with high concentration of Cu and examined between the boot and head emergence phase of growth. Copper toxicity was observed to cause slow ontogenetic development of plants, changing their morphometric parameters (shape, size, colour). To the best of our knowledge, the ultrastructural changes in roots, stems and leaves of H. sativum induced by excess Cu were fully characterized for the first time using transmission electron microscopy. The plant roots were the most effected, showing degradation of the epidermis, reduced number of parenchyma cells, as well as a significant decrease in the diameter of the stele and a disruption and modification to its cell structure. The comparative analysis of the ultrastructure of control plants and plants exposed to the toxic effects of Cu has made it possible to reveal significant disruption of the integrity of the cell wall and cytoplasmic membranes in the root with deposition of electron-dense material. The changes in the ultrastructure of the main cytoplasmic organelles-endoplasmic reticulum, mitochondria, chloroplasts and peroxisomes-in the stem and leaves were found. The cellular Cu deposition, anatomical and ultrastructural modifications could mainly account for the primary impact points of metal toxicity. Therefore, this work extends the available knowledge of the mechanisms of the Cu effect tolerance of barley.


Assuntos
Cobre/toxicidade , Hordeum/efeitos dos fármacos , Poluentes do Solo/toxicidade , Parede Celular/efeitos dos fármacos , Parede Celular/ultraestrutura , Citoplasma/efeitos dos fármacos , Citoplasma/ultraestrutura , Hordeum/anatomia & histologia , Hordeum/citologia , Hordeum/ultraestrutura , Microscopia Eletrônica de Transmissão , Células Vegetais/efeitos dos fármacos , Folhas de Planta/citologia , Folhas de Planta/efeitos dos fármacos , Folhas de Planta/ultraestrutura , Raízes de Plantas/citologia , Raízes de Plantas/efeitos dos fármacos , Raízes de Plantas/ultraestrutura , Caules de Planta/citologia , Caules de Planta/efeitos dos fármacos , Caules de Planta/ultraestrutura , Federação Russa
19.
Plant Cell Physiol ; 61(2): 353-369, 2020 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-31651939

RESUMO

Some plant species have a striking capacity for regeneration in nature, including regeneration of the entire individual from explants. However, due to the lack of suitable experimental models, the regulatory mechanisms of spontaneous whole plant regeneration are mostly unknown. In this study, we established a novel model system to study these mechanisms using an amphibious plant within Brassicaceae, Rorippa aquatica, which naturally undergoes vegetative propagation via regeneration from leaf fragments. Morphological and anatomical observation showed that both de novo root and shoot organogenesis occurred from the proximal side of the cut edge transversely with leaf vascular tissue. Time-series RNA-seq analysis revealed that auxin and cytokinin responses were activated after leaf amputation and that regeneration-related genes were upregulated mainly on the proximal side of the leaf explants. Accordingly, we found that both auxin and cytokinin accumulated on the proximal side. Application of a polar auxin transport inhibitor retarded root and shoot regeneration, suggesting that the enhancement of auxin responses caused by polar auxin transport enhanced de novo organogenesis at the proximal wound site. Exogenous phytohormone and inhibitor applications further demonstrated that, in R. aquatica, both auxin and gibberellin are required for root regeneration, whereas cytokinin is important for shoot regeneration. Our results provide a molecular basis for vegetative propagation via de novo organogenesis.


Assuntos
Desenvolvimento Vegetal/genética , Desenvolvimento Vegetal/fisiologia , Regeneração/genética , Regeneração/fisiologia , Rorippa/crescimento & desenvolvimento , Rorippa/genética , Rorippa/metabolismo , Divisão Celular , Proliferação de Células , Citocininas , Regulação da Expressão Gênica de Plantas , Giberelinas , Ácidos Indolacéticos/metabolismo , Reguladores de Crescimento de Planta , Folhas de Planta/citologia , Folhas de Planta/genética , Folhas de Planta/crescimento & desenvolvimento , Folhas de Planta/metabolismo , Raízes de Plantas/citologia , Raízes de Plantas/crescimento & desenvolvimento , Raízes de Plantas/metabolismo , Brotos de Planta/crescimento & desenvolvimento , Brotos de Planta/metabolismo , Transcriptoma
20.
Plant Cell Physiol ; 61(3): 457-469, 2020 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-31697317

RESUMO

In plants, reversible histone acetylation and deacetylation play a crucial role in various biological activities, including development and the response to environmental stress. Histone deacetylation, which is generally associated with gene silencing, is catalyzed by multiple histone deacetylases (HDACs). Our understanding of HDAC function in plant development has accumulated from molecular genetic studies in Arabidopsis thaliana. By contrast, how HDACs contribute to the development of rice (Oryza sativa) is poorly understood and no rice mutants of HDAC have been reported. Here we have characterized a new rice mutant showing semi-dwarfism, which we named dwarf with slender leaf1 (dsl1). The mutant showed pleiotropic defects in both vegetative and reproductive developments; e.g. dsl1 produced short and narrow leaves, accompanied by a reduction in the number and size of vascular bundles. The semi-dwarf phenotype was due to suppression of the elongation of some culm (stem) internodes. Interestingly, despite this suppression of the upper internodes, the elongation and generation of lower internodes were slightly enhanced. Inflorescence and spikelet development were also affected by the dsl1 mutation. Some of the observed morphological defects were related to a reduction in cell numbers, in addition to reduced cell division in leaf primordia revealed by in situ hybridization analysis, suggesting the possibility that DSL1 is involved in cell division control. Gene cloning revealed that DSL1 encodes an HDAC belonging to the reduced potassium dependence3/histone deacetylase1 family. Collectively, our study shows that the HDAC DSL1 plays diverse and important roles in development in rice.


Assuntos
Sistema Enzimático do Citocromo P-450/metabolismo , Histona Desacetilases/genética , Histona Desacetilases/metabolismo , Oryza/crescimento & desenvolvimento , Oryza/metabolismo , Divisão Celular , Clonagem Molecular , Genes de Plantas , Histonas/metabolismo , Mutação , Oryza/genética , Fenótipo , Folhas de Planta/citologia , Folhas de Planta/crescimento & desenvolvimento , Proteínas de Plantas/metabolismo , Brotos de Planta/citologia , Brotos de Planta/crescimento & desenvolvimento
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