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1.
Dokl Biochem Biophys ; 485(1): 129-131, 2019 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-31201632

RESUMO

This is the first study to isolate the taxoid taxuyunnanin C (group of 14-hydroxylated taxoids) from the biomass of suspension cell culture of the Canadian yew (Taxus canadensis). According to available data, this is the first report of the presence of nonpolar (polyacylated) forms of 14-hydroxylated taxoids, including taxuyunnanin C, in T. canadensis.


Assuntos
Células Vegetais/metabolismo , Taxoides/metabolismo , Taxus/metabolismo , Taxoides/análise , Taxus/citologia
2.
J Agric Food Chem ; 67(27): 7561-7568, 2019 Jul 10.
Artigo em Inglês | MEDLINE | ID: mdl-31246021

RESUMO

The development of botanical applications of nanomaterials has produced a new generation of technologies that can profoundly impact botanical research. Semiconductor quantum dots (QDs) are an archetype nanomaterial and have received significant interest from diverse research communities, owing to their unique and optimizable optical properties. In this review, we describe the most recent progress on QD-based botanical research and discuss the uptake, translocation, and effects of QDs on plants and the potential applications of QDs in botany. A critical evaluation of the current limitations of QD technologies is discussed, along with the future prospects in QD-based botanical research.


Assuntos
Botânica/tendências , Pontos Quânticos , Semicondutores/tendências , Parede Celular/metabolismo , Hidroponia , Células Vegetais/metabolismo , Células Vegetais/ultraestrutura , Desenvolvimento Vegetal , Fenômenos Fisiológicos Vegetais , Plantas/genética , Plantas/metabolismo , Solo
3.
J Photochem Photobiol B ; 196: 111509, 2019 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-31128431

RESUMO

Cnidium officinale Makino is an important medicinal plant of oriental clinics and is considered as the main source of phthalides, polyphenols, and flavonoids. However, there is no available report regarding the effect of different light colors on the secondary metabolites composition of C. officinale. In this study different light (dark, white, blue, red and red: blue) conditions were arranged to raise callus on MS medium containing 0.5 mg·L-1 of each 2,4-D and BAP. Callus grown in dark condition showed maximum (2.0 g) fresh weight with lower total phenolic and flavonoids contents. Also, in dark condition callus faced higher catalase (CAT) and guaiacol peroxidase (GPX) activities to avoid free radicals. Mix (red: blue) light condition favored the synthesis of phenolics and flavonoids in callus at the cost of higher ascorbate peroxidase (APX) and superoxide dismutase (SOD) enzymes expression. However, DPPH free radical scavenging activity was less variable among the samples from the different light conditions. Interestingly, the HPLC profile showed higher (28.3 µg·g-1 DW) phthalide accumulation in dark grown-cultures. Compared to other light conditions, 3-butyledinephthalide accumulation was higher (0.43 µg·g-1 DW) in white light-grown callus. These findings suggest that light conditions play an important role in the regulation of in vitro callus growth and synthesis of important medicinal compounds of C. officinale.


Assuntos
Antioxidantes/metabolismo , Cnidium/química , Flavonoides/metabolismo , Luz , Fenóis/metabolismo , Antioxidantes/química , Ascorbato Peroxidases/metabolismo , Benzofuranos/análise , Benzofuranos/metabolismo , Cromatografia Líquida de Alta Pressão , Cnidium/crescimento & desenvolvimento , Cnidium/metabolismo , Flavonoides/química , Fenóis/química , Células Vegetais/metabolismo , Células Vegetais/efeitos da radiação , Plantas Medicinais/química , Plantas Medicinais/metabolismo , Superóxido Dismutase/metabolismo
4.
J Photochem Photobiol B ; 196: 111505, 2019 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-31129506

RESUMO

Lepidium sativum L. is an important edible, herbaceous plant with huge medicinal value as cardio-protective, hepatoprotective and antitumor agent. This study was designed and performed to investigate biosynthesis of plant's active ingredients in callus cultures of L. sativum in response to the exposure of multi spectral lights. Optimum biomass accumulation (15.36 g/L DW), total phenolic and flavonoid contents (TPC; 47.43 mg/g; TFC; 9.41 mg/g) were recorded in calli placed under white light (24 h) compared to rest of the treatments. Antioxidant enzymatic activities i.e. superoxide dismutase and peroxidase were found optimum in cultures exposed to green light (SOD; 0.054 nM/min/mg FW, POD; 0.501 nM/min/mg FW). Phytochemical analysis further confirmed the potential influence of white light exposure on enhanced production of plant's metabolites. Significant enhancement level of major metabolic compounds such as chlorogenic acid (7.20 mg/g DW), quercetin (22.08 mg/g DW), kaempferol (7.77 mg/g DW) and minor compounds including ferulic acid, sinapic acid, protocatechuic acid, vanillic acid and caffeic acid were recorded in white light compared to control (photoperiod), whereas blue light increased the p-coumaric acid accumulation. Moreover, callus cultures of this plant under white light (24 h) showed highest in vitro based anti-diabetic and antioxidant activities compared to other conditions. Finding of our current study revealed that multi spectral lights are proved to be an effective strategy for enhancing metabolic quantity of antioxidant and anti-diabetic bioactive compounds in callus cultures of L. sativum L.


Assuntos
Antioxidantes/química , Hipoglicemiantes/metabolismo , Lepidium sativum/metabolismo , Luz , Polifenóis/metabolismo , Biomassa , Cromatografia Líquida de Alta Pressão , Hipoglicemiantes/análise , Hipoglicemiantes/química , Lepidium sativum/crescimento & desenvolvimento , Peroxidase/metabolismo , Compostos Fitoquímicos/análise , Células Vegetais/metabolismo , Células Vegetais/efeitos da radiação , Proteínas de Plantas/metabolismo , Polifenóis/análise , Polifenóis/química , Superóxido Dismutase/metabolismo
5.
BMC Plant Biol ; 19(1): 221, 2019 May 28.
Artigo em Inglês | MEDLINE | ID: mdl-31138155

RESUMO

BACKGROUND: Drought stress negatively affects plant growth and productivity. Plants sense soil drought at the root level but the underlying mechanisms remain unclear. At the cell level, we aim to reveal the short-term root perception of drought stress through membrane dynamics. RESULTS: In our study, 15 Medicago truncatula accessions were exposed to a polyethylene glycol (PEG)-induced drought stress, leading to contrasted ecophysiological responses, in particular related to root architecture plasticity. In the reference accession Jemalong A17, identified as drought susceptible, we analyzed lateral roots by imaging of membrane-localized fluorescent probes using confocal microscopy. We found that PEG stimulated endocytosis especially in cells belonging to the growth differentiation zone (GDZ). The mapping of membrane lipid order in cells along the root apex showed that membranes of root cap cells were more ordered than those of more differentiated cells. Moreover, PEG triggered a significant increase in membrane lipid order of rhizodermal cells from the GDZ. We initiated the membrane analysis in the drought resistant accession HM298, which did not reveal such membrane modifications in response to PEG. CONCLUSIONS: Our data demonstrated that the plasma membranes of root cells from a susceptible genotype perceived drought stress by modulating their physical state both via a stimulation of endocytosis and a modification of the degree of lipid order, which could be proposed as mechanisms required for signal transduction.


Assuntos
Secas , Endocitose , Medicago truncatula/fisiologia , Lipídeos de Membrana/metabolismo , Genótipo , Medicago truncatula/genética , Células Vegetais/metabolismo , Células Vegetais/fisiologia , Polietilenoglicóis/administração & dosagem , Rizoma/metabolismo , Rizoma/fisiologia , Estresse Fisiológico
6.
mSphere ; 4(3)2019 05 15.
Artigo em Inglês | MEDLINE | ID: mdl-31092601

RESUMO

Termites forage on a range of substrates, and it has been suggested that diet shapes the composition and function of termite gut bacterial communities. Through comparative analyses of gut metagenomes in nine termite species with distinct diets, we characterize bacterial community compositions and use peptide-based functional annotation method to determine biomass-degrading enzymes and the bacterial taxa that encode them. We find that fungus-growing termite guts have relatively more fungal cell wall-degrading enzyme genes, while wood-feeding termite gut communities have relatively more plant cell wall-degrading enzyme genes. Interestingly, wood-feeding termite gut bacterial genes code for abundant chitinolytic enzymes, suggesting that fungal biomass within the decaying wood likely contributes to gut bacterial or termite host nutrition. Across diets, the dominant biomass-degrading enzymes are predominantly coded for by the most abundant bacterial taxa, suggesting tight links between diet and gut community composition, with the most marked difference being the communities coding for the mycolytic capacity of the fungus-growing termite gut.IMPORTANCE Understanding functional capacities of gut microbiomes is important to improve our understanding of symbiotic associations. Here, we use peptide-based functional annotation to show that the gut microbiomes of fungus-farming termites code for a wealth of enzymes that likely target the fungal diet the termites eat. Comparisons to other termites showed that fungus-growing termite guts have relatively more fungal cell wall-degrading enzyme genes, whereas wood-feeding termite gut communities have relatively more plant cell wall-degrading enzyme genes. Across termites with different diets, the dominant biomass-degrading enzymes are predominantly coded for by the most abundant bacterial taxa, suggesting tight links between diet and gut community compositions.


Assuntos
Dieta , Fungos/crescimento & desenvolvimento , Microbioma Gastrointestinal , Isópteros/enzimologia , Isópteros/microbiologia , Animais , Bactérias/enzimologia , Bactérias/genética , Trato Gastrointestinal/enzimologia , Trato Gastrointestinal/microbiologia , Metagenoma , Filogenia , Células Vegetais/metabolismo , Análise de Sequência de DNA , Simbiose , Madeira/metabolismo
7.
Mol Biol (Mosk) ; 53(2): 179-199, 2019.
Artigo em Russo | MEDLINE | ID: mdl-31099770

RESUMO

At present, pharmacologically significant proteins are synthesized in different expression systems, from bacterial to mammalian and insect cell cultures. The plant expression systems (especially suspension cell culture) combine the simplicity and low cost of bacterial systems with the ability to perform eukaryotic-type posttranslational protein modifications. A low (compared with bacterial systems) yield of the target recombinant protein is one of the shortcomings of the plant expression systems. In this review, methods, developed over the past two decades, to increase the level of recombinant gene expression and methods to prevent silencing, caused by a random insertion of the target gene into heterochromatin region, are considered. The emergence of CRISPR/Cas technologies led to the creation of a new approach to increase the gene expression level, directional insertion of "pharmaceutical" protein genes in specific, knowingly transcriptionally active genome regions. The plant cell housekeeping gene loci, actively expressed throughout the interphase, are these regions. The organization of some housekeeping genes, most promising for transferring recombinant protein genes in their loci, is considered in detail.


Assuntos
Edição de Genes/tendências , Células Vegetais/metabolismo , Proteínas Recombinantes/biossíntese , Proteínas Recombinantes/genética , Animais , Sistemas CRISPR-Cas/genética , Genes Essenciais/genética
8.
Bioengineered ; 10(1): 87-97, 2019 12.
Artigo em Inglês | MEDLINE | ID: mdl-30957636

RESUMO

Expression of recombinant proteins fused to a novel glycomodule tag, termed hydroxyproline (Hyp)-O-glycosylated peptides (HypGP), was earlier found to boost secreted protein yields up to 500-fold in plant cell culture. Here, this technology was applied to the expression of human protease inhibitor α1-antitrypsin (AAT) in tobacco BY-2 cell culture. A designer HypGP tag composed of a 'Ala-Pro' motif of 20 units, or (AP)20, was engineered either at the N- or C-terminal end of AAT. The (AP)20 tag substantially increased the secreted yields of the recombinant AAT up to 34.7 mg/L. However, the (AP)20-tagged AAT products were frequently subjected to proteolytic processing. The intact AAT-(AP)20 along with some of the truncated AAT domains exhibited desired biological activity in inhibiting elastase. The results from this research demonstrated that the designer (AP)20 module engineered in BY-2 cells could function as a molecular carrier to substantially enhance the secreted yields of the recombinant AAT.


Assuntos
Elastase Pancreática/antagonistas & inibidores , Processamento de Proteína Pós-Traducional , Proteínas Secretadas Inibidoras de Proteinases/biossíntese , Proteínas Recombinantes de Fusão/biossíntese , Tabaco/genética , alfa 1-Antitripsina/biossíntese , Sequência de Bases , Técnicas de Cultura de Células , Dipeptídeos/genética , Dipeptídeos/metabolismo , Expressão Gênica , Glicosilação , Humanos , Elastase Pancreática/metabolismo , Peptídeos/genética , Peptídeos/metabolismo , Células Vegetais/metabolismo , Plasmídeos/química , Plasmídeos/metabolismo , Proteínas Secretadas Inibidoras de Proteinases/genética , Proteínas Secretadas Inibidoras de Proteinases/isolamento & purificação , Proteínas Secretadas Inibidoras de Proteinases/farmacologia , Proteínas Recombinantes de Fusão/genética , Proteínas Recombinantes de Fusão/isolamento & purificação , Proteínas Recombinantes de Fusão/farmacologia , Tabaco/citologia , Tabaco/metabolismo , Transformação Genética , alfa 1-Antitripsina/genética , alfa 1-Antitripsina/isolamento & purificação , alfa 1-Antitripsina/farmacologia
9.
J Photochem Photobiol B ; 193: 140-147, 2019 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-30852387

RESUMO

Light is the most important physical factor in growth and development of plants. Light intensity is directly proportional to the growth and accumulation of natural antioxidants during in vitro cultures of various medicinal plants. The present research study was designed to determine the effect of different light intensities i.e. normal light (2000-2500 lx), diffused light (500-1000 lx) and complete dark (0 lx) on callus growth dynamics and production of natural antioxidants in olive cult. Arbosana. Highest callus induction frequency (50%) was observed in the stem explants pre-treated with silver nanoparticles suspension (AgNPs: 50 ppm) and cultured on MS media supplemented with combination of 6-Benzylaminopurine (BAP: 2 mg/l), Gibberellic acid (GA3: 1.5 mg/l) plus Naphthalene acetic acid (NAA: 0.5 mg/l). Maximum callus biomass (FW = 1414 mg/l) was recorded when the cultured explants were incubated initially for seven days in complete darkness, followed by transference to diffused light for one week and then finally placed under normal light in total fifty six days culture period. Moreover, phytochemical analysis of the callus cultures showed significantly higher activities of antioxidant enzymes i.e. SOD, POD, CAT and APx (2.45, 2.96, 2.57 and 1.67 U/mg. protein) in the callus cultures grown under dark condition as compared with other light treatments. For non-enzymatic antioxidant potential, maximum activity of TPC, TFC, PAL and DPPH (2.42 mg GAE/g, 1.50 mg QAE/g, 3.95 U/mg and 75%) were recorded in the calli raised in vitro under diffused light. This is the first report on the production of natural antioxidants in response to different light intensities in callus cultures of Olea europaea. Future studies should focus on large scale production of callus cultures in order to yield maximum biomass from this high valued plant.


Assuntos
Antioxidantes/metabolismo , Biomassa , Luz , Olea/efeitos da radiação , Antioxidantes/química , Compostos de Benzil/química , Catalase/metabolismo , Giberelinas/química , Nanopartículas Metálicas/química , Olea/citologia , Olea/metabolismo , Células Vegetais/metabolismo , Proteínas de Plantas/metabolismo , Purinas/química , Prata/química , Superóxido Dismutase/metabolismo
10.
Int J Mol Sci ; 20(6)2019 Mar 20.
Artigo em Inglês | MEDLINE | ID: mdl-30897737

RESUMO

In plant cells, calcium (Ca2+) serves as a versatile intracellular messenger, participating in several fundamental and important biological processes. Recent studies have shown that the actin cytoskeleton is not only an upstream regulator of Ca2+ signaling, but also a downstream regulator. Ca2+ has been shown to regulates actin dynamics and rearrangements via different mechanisms in plants, and on this basis, the upstream signaling encoded within the Ca2+ transient can be decoded. Moreover, actin dynamics have also been proposed to act as an upstream of Ca2+, adjust Ca2+ oscillations, and establish cytosolic Ca2+ ([Ca2+]cyt) gradients in plant cells. In the current review, we focus on the advances in uncovering the relationship between the actin cytoskeleton and calcium in plant cells and summarize our current understanding of this relationship.


Assuntos
Citoesqueleto de Actina/classificação , Citoesqueleto de Actina/metabolismo , Sinalização do Cálcio/fisiologia , Células Vegetais/metabolismo , Tubo Polínico/metabolismo
11.
Planta ; 250(1): 79-94, 2019 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-30919065

RESUMO

MAIN CONCLUSION: Mouse FIT2 protein redirects the cytoplasmic terpene biosynthetic machinery to lipid-droplet-forming domains in the ER and this relocalization supports the efficient compartmentalization and accumulation of sesquiterpenes in plant cells. Mouse (Mus musculus) fat storage-inducing transmembrane protein 2 (MmFIT2), an endoplasmic reticulum (ER)-resident protein with an important role in lipid droplet (LD) biogenesis in mammals, can function in plant cells to promote neutral lipid compartmentalization. Surprisingly, in affinity capture experiments, the Nicotiana benthamiana 5-epi-aristolochene synthase (NbEAS), a soluble cytoplasm-localized sesquiterpene synthase, was one of the most abundant proteins that co-precipitated with GFP-tagged MmFIT2 in transient expression assays in N. benthamiana leaves. Consistent with results of pull-down experiments, the subcellular location of mCherry-tagged NbEAS was changed from the cytoplasm to the LD-forming domains in the ER, only when co-expressed with MmFIT2. Ectopic co-expression of NbEAS and MmFIT2 together with mouse diacylglycerol:acyl-CoA acyltransferase 2 (MmDGAT2) in N. benthamiana leaves substantially increased the numbers of cytoplasmic LDs and supported the accumulation of the sesquiterpenes, 5-epi-aristolochene and capsidiol, up to tenfold over levels elicited by Agrobacterium infection alone. Taken together, our results suggest that MmFIT2 recruits sesquiterpene synthetic machinery to ER subdomains involved in LD formation and that this process can enhance the efficiency of sesquiterpene biosynthesis and compartmentalization in plant cells. Further, MmFIT2 and MmDGAT2 represent cross-kingdom lipogenic protein factors that may be used to engineer terpene accumulation more broadly in the cytoplasm of plant vegetative tissues.


Assuntos
Gotículas Lipídicas/metabolismo , Proteínas de Membrana/metabolismo , Sesquiterpenos/metabolismo , Tabaco/metabolismo , Triglicerídeos/metabolismo , Animais , Vias Biossintéticas , Citoplasma/metabolismo , Retículo Endoplasmático/metabolismo , Gotículas Lipídicas/química , Proteínas de Membrana/genética , Camundongos , Especificidade de Órgãos , Células Vegetais/metabolismo , Folhas de Planta/citologia , Folhas de Planta/genética , Folhas de Planta/metabolismo , Proteômica , Sesquiterpenos/análise , Terpenos/metabolismo , Tabaco/citologia , Tabaco/genética , Triglicerídeos/análise
12.
Postepy Biochem ; 65(1): 58-71, 2019 Mar 22.
Artigo em Polonês | MEDLINE | ID: mdl-30901184

RESUMO

Plant immunity is constituted by multilayered system involving two intertwined lines of defence: a first level of immunity termed PAMP-triggered immunity (PTI) or basal resistance, and a second layer of plant defence, called effector-triggered immunity (ETI). The second line of defence depends on the ability of the plant to recognize phytopathogen-synthesized effector proteins delivered into host plant cells. The effector proteins employ common as well as pathogen-specific strategies to disturb plant immunity and to promote pathogen survival and favor their multiplication. They target pattern-recognition receptors (PRRs) and key components in the PTI signaling pathways, as well as, they interfere with many cellular processes including vesicle transport, cytoskeleton reorganization, proteasome-dependent protein degradation, phytohormone biosynthesis and signaling, and gene expression. This results in effector-triggered susceptibility (ETS). However, in some cases, pathogen effectors are recognized by plant intracellular immune receptors NB-LRR/NLR that identify effector proteins. Conformational changes in the NB-LRR/NLR immune receptors accompanying the recognition of the effector proteins activate intracellular signaling pathways initiating a whole range of defence responses that form the second line of local defence.


Assuntos
Proteínas de Bactérias/metabolismo , Células Vegetais/imunologia , Células Vegetais/metabolismo , Doenças das Plantas/imunologia , Imunidade Vegetal , Receptores de Reconhecimento de Padrão/antagonistas & inibidores , Proteínas Virais/metabolismo , Proteínas de Bactérias/biossíntese , Células Vegetais/microbiologia , Células Vegetais/virologia , Doenças das Plantas/microbiologia , Doenças das Plantas/virologia , Receptores de Reconhecimento de Padrão/imunologia , Proteínas Virais/biossíntese
13.
Plant Sci ; 281: 146-158, 2019 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-30824047

RESUMO

Plant cells use autophagy to degrade their own cytoplasm in vacuoles, thereby not only recycling their breakdown products, but also ensuring the homeostasis of essential cytoplasmic constituents and organelles. Plants and other eukaryotes have a conserved set of core Autophagy-related (ATG) genes involved in the biogenesis of the autophagosome, the main autophagic compartment destined for the lytic vacuole. In the past decade, the core ATG genes were isolated from several plant species. The core ATG proteins include the components of the VACUOLAR PROTEIN SORTING 34 (VPS34) complex that is responsible for the local production of phosphatidylinositol 3-phosphate (PI3P) at the site of autophagosome formation. Dissecting the roles of PI3P and its effectors in autophagy is challenging, because of the multi-faceted links between autophagosomal and endosomal systems. This review highlights recent studies on putative plant PI3P effectors involved in autophagosome dynamics. Molecular mechanisms underlying the requirement of PI3P for autophagosome biogenesis and trafficking are also discussed.


Assuntos
Autofagia/fisiologia , Fosfatidilinositóis/metabolismo , Células Vegetais/metabolismo , Proteínas de Arabidopsis/metabolismo , Endossomos/metabolismo , Fosfatos de Fosfatidilinositol/metabolismo , Proteínas de Transporte Vesicular/metabolismo
14.
Plant Physiol Biochem ; 137: 93-101, 2019 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-30771565

RESUMO

Aluminum (Al) toxicity in the acid soils (pH ≤ 5) is the major limiting abiotic factor affecting the productivity of crops. Boron (B) has been reported to alleviate Al toxicity. In spite of recent advances, it is not clear how B relieves Al toxicity. Results demonstrated that Al toxicity hampered the root elongation. Moreover, lumogallion fluorescent molecular probe unequivocally localized mostly bound Al to the periphery of the cell wall (CW) and to the nuclei. Additionally, Al toxicity induced variations in the CW components through the accumulation of pectin and hemicellulose. Nevertheless, B supply reduced callose deposition, increased root growth and reduced changes in the CW components under Al toxicity. Moreover, B supply reduced the un-methylated pectin while increased the degree of methyl esterification of pectin. These results imply that B due to its role in the CW formation could reduce aluminum-induced negative effects on plant growth by attenuating apoplastic Al3+ and changes in the CW components which ultimately results in the improved root growth.


Assuntos
Alumínio/toxicidade , Antioxidantes/metabolismo , Boro/farmacologia , Parede Celular/efeitos dos fármacos , Citrus/efeitos dos fármacos , Alumínio/análise , Alumínio/farmacocinética , Ácido Ascórbico/metabolismo , Boro/farmacocinética , Parede Celular/química , Citrus/citologia , Citrus/metabolismo , Glucanos/metabolismo , Microscopia Confocal , Monoaminoxidase/metabolismo , Células Vegetais/efeitos dos fármacos , Células Vegetais/metabolismo , Folhas de Planta/metabolismo , Proteínas de Plantas/metabolismo , Raízes de Plantas/efeitos dos fármacos , Raízes de Plantas/crescimento & desenvolvimento , Raízes de Plantas/metabolismo , Análise de Componente Principal , Xantina Oxidase/metabolismo
15.
Plant Physiol ; 179(4): 1486-1501, 2019 04.
Artigo em Inglês | MEDLINE | ID: mdl-30700539

RESUMO

The skin of fleshy fruit is typically covered by a thick cuticle. Some fruit species develop different forms of layers directly above their skin. Reticulation, for example, is a specialized suberin-based coating that ornaments some commercially important melon (Cucumis melo) fruit and is an important quality trait. Despite its importance, the structural, molecular, and biochemical features associated with reticulation are not fully understood. Here, we performed a multilevel investigation of structural attributes, chemical composition, and gene expression profiles on a set of reticulated and smooth skin melons. High-resolution microscopy, surface profiling, and histochemical staining assays show that reticulation comprises cells with heavily suberized walls accumulating large amounts of typical suberin monomers, as well as lignified cells localized underneath the specialized suberized cell layer. Reticulated skin was characterized by induced expression of biosynthetic genes acting in the core phenylpropanoid, suberin, lignin, and lignan pathways. Transcripts of genes associated with lipid polymer assembly, cell wall organization, and loosening were highly enriched in reticulated skin tissue. These signatures were exclusive to reticulated structures and absent in both the smooth surfaces observed in between reticulated regions and in the skin of smooth fruit. Our data provide important insights into the molecular and metabolic bases of reticulation and its tight association with skin ligno-suberization during melon fruit development. Moreover, these insights are likely to contribute to melon breeding programs aimed at improving postharvest qualities associated with fleshy fruit surface layers.


Assuntos
Cucumis/anatomia & histologia , Frutas/anatomia & histologia , Vias Biossintéticas/genética , Parede Celular/ultraestrutura , Cucumis/genética , Cucumis/crescimento & desenvolvimento , Frutas/genética , Frutas/crescimento & desenvolvimento , Regulação da Expressão Gênica de Plantas , Lipídeos/biossíntese , Lipídeos de Membrana/biossíntese , Metabolômica , Fenótipo , Células Vegetais/metabolismo , RNA Mensageiro , Propriedades de Superfície
16.
Plant Cell Rep ; 38(8): 847-867, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-30739138

RESUMO

Gamma-aminobutyric acid (GABA), a four-carbon non-protein amino acid, is found in most prokaryotic and eukaryotic organisms. Although, ample research into GABA has occurred in mammals as it is a major inhibitory neurotransmitter; in plants, a role for GABA has often been suggested as a metabolite that changes under stress rather than as a signal, as no receptor or motif for GABA binding was identified until recently and many aspects of its biological function (ranging from perception to function) remain to be answered. In this review, flexible properties of GABA in regulation of plant responses to various environmental biotic and abiotic stresses and its integration in plant growth and development either as a metabolite or a signaling molecule are discussed. We have elaborated on the role of GABA in stress adaptation (i.e., salinity, hypoxia/anoxia, drought, temperature, heavy metals, plant-insect interplay and ROS-related responses) and its contribution in non-stress-related biological pathways (i.e., involvement in plant-microbe interaction, contribution to the carbon and nitrogen metabolism and governing of signal transduction pathways). This review aims to represent the multifunctional contribution of GABA in various biological and physiological mechanisms under stress conditions; the objective is to review the current state of knowledge about GABA role beyond stress-related responses. Our effort is to place findings about GABA in an organized and broader context to highlight its shared metabolic and biologic functions in plants under variable conditions. This will provide potential modes of GABA crosstalk in dynamic plant cell responses.


Assuntos
Células Vegetais/metabolismo , Ácido gama-Aminobutírico/metabolismo , Regulação da Expressão Gênica de Plantas/fisiologia , Reguladores de Crescimento de Planta/metabolismo , Estresse Fisiológico/fisiologia
17.
Nat Plants ; 5(2): 194-203, 2019 02.
Artigo em Inglês | MEDLINE | ID: mdl-30737512

RESUMO

During arbuscular mycorrhizal (AM) symbiosis, cells within the root cortex develop a matrix-filled apoplastic compartment in which differentiated AM fungal hyphae called arbuscules reside. Development of the compartment occurs rapidly, coincident with intracellular penetration and rapid branching of the fungal hypha, and it requires much of the plant cell's secretory machinery to generate the periarbuscular membrane that delimits the compartment. Despite recent advances, our understanding of the development of the periarbuscular membrane and the transfer of molecules across the symbiotic interface is limited. Here, using electron microscopy and tomography, we reveal that the periarbuscular matrix contains two types of membrane-bound compartments. We propose that one of these arises as a consequence of biogenesis of the periarbuscular membrane and may facilitate movement of molecules between symbiotic partners. Additionally, we show that the arbuscule contains massive arrays of membrane tubules located between the protoplast and the cell wall. We speculate that these tubules may provide the absorptive capacity needed for nutrient assimilation and possibly water absorption to enable rapid hyphal expansion.


Assuntos
Membrana Celular/fisiologia , Micorrizas/fisiologia , Células Vegetais/microbiologia , Raízes de Plantas/citologia , Raízes de Plantas/microbiologia , Membrana Celular/ultraestrutura , Tomografia com Microscopia Eletrônica , Medicago truncatula/genética , Medicago truncatula/microbiologia , Microscopia Eletrônica , Mutação , Micorrizas/ultraestrutura , Células Vegetais/metabolismo , Proteínas de Plantas/metabolismo , Plantas Geneticamente Modificadas , Simbiose
18.
Int J Mol Sci ; 20(2)2019 Jan 17.
Artigo em Inglês | MEDLINE | ID: mdl-30658467

RESUMO

Heat Shock Factor A2 (HsfA2) is part of the Heat Shock Factor (HSF) network, and plays an essential role beyond heat shock in environmental stress responses and cellular homeostatic control. Arabidopsis thaliana cell cultures derived from wild type (WT) ecotype Col-0 and a knockout line deficient in the gene encoding HSFA2 (HSFA2 KO) were grown aboard the International Space Station (ISS) to ascertain whether the HSF network functions in the adaptation to the novel environment of spaceflight. Microarray gene expression data were analyzed using a two-part comparative approach. First, genes differentially expressed between the two environments (spaceflight to ground) were identified within the same genotype, which represented physiological adaptation to spaceflight. Second, gene expression profiles were compared between the two genotypes (HSFA2 KO to WT) within the same environment, which defined genes uniquely required by each genotype on the ground and in spaceflight-adapted states. Results showed that the endoplasmic reticulum (ER) stress and unfolded protein response (UPR) define the HSFA2 KO cells' physiological state irrespective of the environment, and likely resulted from a deficiency in the chaperone-mediated protein folding machinery in the mutant. Results further suggested that additional to its universal stress response role, HsfA2 also has specific roles in the physiological adaptation to spaceflight through cell wall remodeling, signal perception and transduction, and starch biosynthesis. Disabling HsfA2 altered the physiological state of the cells, and impacted the mechanisms induced to adapt to spaceflight, and identified HsfA2-dependent genes that are important to the adaption of wild type cells to spaceflight. Collectively these data indicate a non-thermal role for the HSF network in spaceflight adaptation.


Assuntos
Adaptação Biológica/genética , Diferenciação Celular , Fatores de Transcrição de Choque Térmico/genética , Células Vegetais/metabolismo , Células Vegetais/efeitos da radiação , Voo Espacial , Diferenciação Celular/genética , Células Cultivadas , Perfilação da Expressão Gênica , Regulação da Expressão Gênica de Plantas , Técnicas de Inativação de Genes , Genótipo , Fatores de Transcrição de Choque Térmico/metabolismo , Modelos Biológicos , Ausência de Peso
19.
Development ; 146(1)2019 01 09.
Artigo em Inglês | MEDLINE | ID: mdl-30626594

RESUMO

A reduced rate of stem cell division is considered a widespread feature which ensures the integrity of genetic information during somatic development of plants and animals. Radial growth of plant shoots and roots is a stem cell-driven process that is fundamental for the mechanical and physiological support of enlarging plant bodies. In most dicotyledonous species, the underlying stem cell niche, the cambium, generates xylem inwards and phloem outwards. Despite the importance and intriguing dynamics of the cambium, the functional characterization of its stem cells is hampered by the lack of experimental tools for accessing distinct cambium sub-domains. Here, we use the hypocotyl of Arabidopsis thaliana to map stem cell activity in the proliferating cambium. Through pulse labeling and genetically encoded lineage tracing, we find that a single bifacial stem cell generates both xylem and phloem cell lineages. This cell is characterized by a specific combination of PXY (TDR), SMXL5 and WOX4 gene activity and a high division rate in comparison with tissue-specific progenitors. Our analysis provides a cellular fate map of radial plant growth, and suggests that stem cell quiescence is not a general prerequisite for life-long tissue production.This article has an associated 'The people behind the papers' interview.


Assuntos
Arabidopsis/crescimento & desenvolvimento , Câmbio/fisiologia , Floema/fisiologia , Células Vegetais/metabolismo , Desenvolvimento Vegetal/fisiologia , Células-Tronco/metabolismo , Xilema/fisiologia , Arabidopsis/citologia , Proteínas de Arabidopsis/biossíntese , Câmbio/citologia , Regulação da Expressão Gênica de Plantas/fisiologia , Hipocótilo/citologia , Hipocótilo/fisiologia , Floema/citologia , Raízes de Plantas/citologia , Raízes de Plantas/fisiologia , Células-Tronco/citologia , Xilema/citologia
20.
Molecules ; 24(3)2019 Jan 27.
Artigo em Inglês | MEDLINE | ID: mdl-30691226

RESUMO

Plastids are sites for carotenoid biosynthesis and accumulation, but detailed information on fruit plastid development and its relation to carotenoid accumulation remains largely unclear. Here, using Baisha (BS; white-fleshed) and Luoyangqing (LYQ; red-fleshed) loquat (Eriobotrya japonica), a detailed microscopic analysis of plastid development during fruit ripening was carried out. In peel cells, chloroplasts turned into smaller chromoplasts in both cultivars, and the quantity of plastids in LYQ increased by one-half during fruit ripening. The average number of chromoplasts per peel cell in fully ripe fruit was similar between the two cultivars, but LYQ peel cell plastids were 20% larger and had a higher colour density, associated with the presence of larger plastoglobules. In flesh cells, chromoplasts could be observed only in LYQ during the middle and late stages of ripening, and the quantity on a per-cell basis was higher than that in peel cells, but the size of chromoplasts was smaller. It was concluded that chromoplasts are derived from the direct conversion of chloroplasts to chromoplasts in the peel, and from de novo differentiation of proplastids into chromoplasts in flesh. The relationship between plastid development and carotenoid accumulation is discussed.


Assuntos
Eriobotrya/citologia , Eriobotrya/genética , Frutas/citologia , Frutas/genética , Células Vegetais/metabolismo , Plastídeos/genética , Carotenoides/metabolismo , Eriobotrya/anatomia & histologia , Eriobotrya/metabolismo , Frutas/anatomia & histologia , Frutas/metabolismo , Microscopia , Fenótipo , Células Vegetais/ultraestrutura
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