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1.
Int J Mol Sci ; 22(23)2021 Nov 23.
Artigo em Inglês | MEDLINE | ID: mdl-34884435

RESUMO

Plants reorient the growth of affected organs in response to the loss of gravity vector. In trees, this phenomenon has received special attention due to its importance for the forestry industry of conifer species. Sustainable management is a key factor in improving wood quality. It is of paramount importance to understand the molecular and genetic mechanisms underlying wood formation, together with the hormonal and environmental factors that affect wood formation and quality. Hormones are related to the modulation of vertical growth rectification. Many studies have resulted in a model that proposes differential growth in the stem due to unequal auxin and jasmonate allocation. Furthermore, many studies have suggested that in auxin distribution, flavonoids act as molecular controllers. It is well known that flavonoids affect auxin flux, and this is a new area of study to understand the intracellular concentrations and how these compounds can control the gravitropic response. In this review, we focused on different molecular aspects related to the hormonal role in flavonoid homeostasis and what has been done in conifer trees to identify molecular players that could take part during the gravitropic response and reduce low-quality wood formation.

2.
Plant Physiol Biochem ; 168: 465-476, 2021 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-34717178

RESUMO

Expansins are proteins involved in cell wall metabolism that play an important role in plant growth, development, fruit ripening and abiotic stress tolerance. In the present study, we analyzed putative expansins that respond to drought stress. Five expansin genes were identified in cDNA libraries isolated from Colobanthus quitensis gown either with or without endophytic fungi under hydric stress. A differential transcript abundance was observed by qPCR analysis upon drought stress. To compare these expansin genes, and to suggest a possible mechanism of action at the molecular level, the structural model of the deduced proteins was obtained by comparative modeling methodology. The structures showed two domains and an open groove on the surface of the proteins was observed in the five structural models. The proteins were evaluated in terms of their protein-ligand interactions using four different ligands. The results suggested differences in their mode of protein-ligand interaction, in particular concerning the residues involved in the protein-ligand interaction. The presented evidence supports the participation of some members of the expansin multiprotein family in the response to drought stress in C. quitensis and suggest that the response is modulated by endophytic fungi.

3.
Cells ; 10(8)2021 08 15.
Artigo em Inglês | MEDLINE | ID: mdl-34440864

RESUMO

Approximately thirty percent of the proteins synthesized in animal or plant cells travel through the secretory pathway. Seventy to eighty percent of those proteins are glycosylated. Thus, glycosylation is an important protein modification that is related to many cellular processes, such as differentiation, recognition, development, signal transduction, and immune response. Additionally, glycosylation affects protein folding, solubility, stability, biogenesis, and activity. Specifically, in plants, glycosylation has recently been related to the fruit ripening process. This review aims to provide valuable information and discuss the available literature focused on three principal topics: (I) glycosylations as a key posttranslational modification in development in plants, (II) experimental and bioinformatics tools to analyze glycosylations, and (III) a literature review related to glycosylations in fruit ripening. Based on these three topics, we propose that it is necessary to increase the number of studies related to posttranslational modifications, specifically protein glycosylation because the specific role of glycosylation in the posttranslational process and how this process affects normal fruit development and ripening remain unclear to date.


Assuntos
Frutas/crescimento & desenvolvimento , Glicoproteínas/metabolismo , Proteínas de Plantas/metabolismo , Sementes/crescimento & desenvolvimento , Biologia Computacional , Frutas/metabolismo , Regulação da Expressão Gênica de Plantas , Glicosilação , Processamento de Proteína Pós-Traducional , Sementes/metabolismo
4.
Polymers (Basel) ; 13(13)2021 Jun 24.
Artigo em Inglês | MEDLINE | ID: mdl-34202791

RESUMO

The aim of this work was to characterize and optimize the formation of molecular complexes produced by the association of calcium alginate and reduced glutathione (GSH). The influence of varying concentrations of calcium and GSH on the production of microcapsules was analyzed using response surface methodology (RSM). The microcapsules were characterized by thermogravimetric analysis (TGA-DTG) and infrared spectroscopy (FTIR) in order to assess the hydration of the complexes, their thermal stability, and the presence of GSH within the complexes. The optimum conditions proposed by RSM to reach the maximum concentration of GSH within complexes were a 15% w/v of GSH and 1.25% w/v of CaCl2, with which a theorical concentration of 0.043 mg GSH per mg of CAG complex was reached.

5.
Int J Mol Sci ; 22(12)2021 Jun 11.
Artigo em Inglês | MEDLINE | ID: mdl-34208198

RESUMO

The role of auxin in the fruit-ripening process during the early developmental stages of commercial strawberry fruits (Fragaria x ananassa) has been previously described, with auxin production occurring in achenes and moving to the receptacle. Additionally, fruit softening is a consequence of the depolymerization and solubilization of cell wall components produced by the action of a group of proteins and enzymes. The aim of this study was to compare the effect of exogenous auxin treatment on the physiological properties of the cell wall-associated polysaccharide contents of strawberry fruits. We combined thermogravimetric (TG) analysis with analyses of the mRNA abundance, enzymatic activity, and physiological characteristics related to the cell wall. The samples did not show a change in fruit firmness at 48 h post-treatment; by contrast, we showed changes in the cell wall stability based on TG and differential thermogravimetric (DTG) analysis curves. Less degradation of the cell wall polymers was observed after auxin treatment at 48 h post-treatment. The results of our study indicate that auxin treatment delays the cell wall disassembly process in strawberries.


Assuntos
Biopolímeros/metabolismo , Parede Celular/metabolismo , Fragaria/metabolismo , Frutas/metabolismo , Ácidos Indolacéticos/farmacologia , Parede Celular/efeitos dos fármacos , Parede Celular/genética , Fragaria/efeitos dos fármacos , Fragaria/genética , Frutas/efeitos dos fármacos , Frutas/genética , Regulação da Expressão Gênica de Plantas/efeitos dos fármacos , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Temperatura , Termogravimetria , Transcrição Genética/efeitos dos fármacos , Ácidos Tri-Iodobenzoicos/farmacologia
6.
Biomed Res Int ; 2021: 6683877, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33981771

RESUMO

Since the intake of fruits and vegetables displays important effects on the incidence of several chronic diseases in humans, consumers' attention worldwide is focused on the identification of functional foods. In this sense, Ugni molinae (murtilla or murta fruit) is an important source of molecules with a strong antioxidant capacity that is widely used as a medicinal plant in Southern Argentina-Chile. Research on murtilla berries showed that this fruit and its leaves can be an excellent source of polyphenols and bioactive compounds with antibacterial and antioxidant capacity. This review is aimed at providing valuable information and discussing the available literature focused on four principal points: (i) fruit quality and plant physiology, (ii) compound content with bioactive properties, (iii) health properties for consumers of the fruit and leaves, and (iv) challenges for future research. Based on these four points, we propose that murtilla fruit can be a potential ingredient for new functional food products.


Assuntos
Frutas , Myrtaceae , Extratos Vegetais , Antioxidantes/química , Argentina , Chile , Frutas/química , Frutas/metabolismo , Alimento Funcional , Myrtaceae/química , Myrtaceae/metabolismo , Odorantes , Extratos Vegetais/análise , Extratos Vegetais/química , Compostos Orgânicos Voláteis/análise , Compostos Orgânicos Voláteis/química
7.
Sci Rep ; 10(1): 11310, 2020 07 09.
Artigo em Inglês | MEDLINE | ID: mdl-32647129

RESUMO

The phytohormone jasmonoyl-isoleucine (JA-Ile) regulates fundamental plant processes as developmental and defense responses. JA-Ile mediates the interaction between the F-box protein COI1 (part of the SCFCOI1 E3 ubiquitin ligase) and a JAZ repressor leading to early jasmonate responses. The Arabidopsis JAZ1 protein contains the canonical LPIARR degron sequence, which is responsible for the stabilization of the AtCOI1-JA-Ile-AtJAZ1 complex. In strawberry (Fragaria × ananassa) JAZ family was described at the transcriptional level during fruit development but the information about the interaction mode of this complex is still scarce at the molecular level. To gain insight into the strawberry JA-Ile receptor complex, we evaluated the interaction at the structural level, and protein models were built and analyzed for FaCOI1 and FaJAZ1, FaJAZ8.1, and FaJAZ10. The interaction between FaCOI1 and FaJAZ1, FaJAZ8.1 and FaJAZ10 were explored using several ligands, through molecular docking and molecular dynamics (MD) simulations, finding the strongest interaction with (+)-7-iso-JA-Ile than other ligands. Additionally, we tested interactions between FaCOI1 and FaJAZs by yeast two-hybrid assays in the presence of coronatine (COR, a JA-Ile mimic). We detected strong COR-dependent interactions between FaCOI1 and FaJAZ1. Interestingly, FaJAZ1 contains a new non-canonical (IPMQRK) functional degron sequence, in which Arg and Lys are the key residues for maintaining the interaction of the FaCOI1-COR-FaJAZ1 complex as we observed in mutated versions of the FaJAZ1 degron. Phylogenetic analysis showed that the IPMQRK degron is only present in orthologs belonging to the Rosoideae but not in other Rosaceae subfamilies. Together, this study uncovers a new degron sequence in plants, which could be required to make an alternative and functional JA-Ile perception complex in strawberry.


Assuntos
Fragaria/química , Proteínas de Plantas/química , Aminoácidos/metabolismo , Fragaria/genética , Indenos/metabolismo , Filogenia , Proteínas de Plantas/genética , Ligação Proteica , Conformação Proteica
8.
Plant Physiol Biochem ; 154: 581-589, 2020 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-32711363

RESUMO

Cell wall modification is one of the main factors that produce the tissue softening during ripening of many fruit including strawberry (Fragaria x ananassa). Expansins have been studied for over 20 years as a class of the important cell growth regulators, and in the last years these have been related with the fruit softening. In strawberry, five partial sequences of the expansins genes were described in the past, this analysis showed that FaEXP5 partial gene was present throughout fruit development, but was more strongly expressed during ripening. Now, we reported the full length of this α-expansin (FaEXPA5), whose had been related with fruit softening, and the protein structural was described by homology model. Their transcript accumulation during softening was confirmed by qRT-PCR, displaying a high accumulation rate during fruit ripening. In silico analysis of promoter sequence showed four ABA and two auxin cis-regulatory elements, potentially responsible for the expression patterns observed in response to the hormone treatments. Additionally, 3D protein model displayed two domains and one open groove characteristic of expansin structures. The protein-ligand interactions were evaluated by molecular dynamic (MD) simulation using three different long structure ligands (a cellulose fiber, a xyloglucan fiber (XXXG type), and a pectin fiber as control). Favorable interactions were observed with xyloglucan and cellulose, being cellulose the best ligand with lower RMSD value. Additionally, MD simulations showed that FaEXPA5 can interact with the ligands through residues present in the open groove along the two domains.


Assuntos
Parede Celular/fisiologia , Fragaria/fisiologia , Frutas/fisiologia , Proteínas de Plantas/fisiologia , Regulação da Expressão Gênica de Plantas
9.
Comput Biol Chem ; 87: 107279, 2020 May 30.
Artigo em Inglês | MEDLINE | ID: mdl-32505880

RESUMO

Tissue softening accompanies the ripening of many fruits and initiates the processes of irreversible deterioration. Expansins are plant cell wall proteins that have been proposed to disrupt hydrogen bonds within the cell wall polymer matrix. Several authors have shown that FaEXPA2 is a key gene that shows an increased expression level during ripening and softening of the strawberry fruit. For this reason, FaEXPA2 is frequently used as a molecular marker of softening in strawberry fruit, and changes in its relative expression have been related to changes in fruit firmness. In this context, we previously reported that FaEXPA2 has a high accumulation rate during fruit ripening in four different strawberry cultivars; however, the molecular mechanism of FaEXPA2 or expansins in general is not yet clear. Herein, a 3D model of the FaEXPA2 protein was built by comparative modeling to understand how FaEXPA2 interacts with different cell wall components at the molecular level. First, the structure was shown to display two domains characteristic of the other expansins that were previously described. The protein-ligand interaction was evaluated by molecular dynamic (MD) simulation using four different long ligands (a cellulose fiber, two of the more important xyloglucan (XG) fibers found in strawberry (XXXG and XXFG type), and a pectin (homogalacturonic acid type)). The results showed that FaEXPA2 formed a more stable complex with cellulose than other ligands via the different residues present in the open groove surface of its two domains, while FaEXPA2 did not interact with the pectin ligand.

10.
Int J Mol Sci ; 21(9)2020 May 11.
Artigo em Inglês | MEDLINE | ID: mdl-32403246

RESUMO

Xyloglucan endotransglycosylase/hydrolases (XTHs) are cell wall enzymes with hydrolase (XEH) and/or endotransglycosylase (XET) activities. As they are involved in the modification of the xyloglucans, a type of hemicellulose present in the cell wall, they are believed to be very important in different processes, including growth, development, and fruit ripening. Previous studies suggest that XTHs might play a key role in development and ripening of Fragaria chiloensis fruit, and its characterization is pending. Therefore, in order to provide a biochemical characterization of the FcXTH2 enzyme to explain its possible role in strawberry development, the molecular cloning and the heterologous expression of FcXTH2 were performed. The recombinant FcXTH2 was active and displayed mainly XEH activity. The optimal pH and temperature are 5.5 and 37 °C, respectively. A KM value of 0.029 mg mL-1 was determined. Additionally, its protein structural model was built through comparative modeling methodology. The model showed a typically ß-jelly-roll type folding in which the catalytic motif was oriented towards the FcXTH2 central cavity. Using molecular docking, protein-ligand interactions were explored, finding better interaction with xyloglucan than with cellulose. The data provided groundwork for understanding, at a molecular level, the enzymatic mechanism of FcXTH2, an important enzyme acting during the development of the Chilean strawberry.


Assuntos
Fragaria/enzimologia , Frutas/enzimologia , Glicosiltransferases/metabolismo , Hidrolases/metabolismo , Proteínas de Plantas/metabolismo , Parede Celular/genética , Parede Celular/metabolismo , Chile , Clonagem Molecular , Fragaria/genética , Fragaria/crescimento & desenvolvimento , Frutas/genética , Frutas/crescimento & desenvolvimento , Regulação da Expressão Gênica no Desenvolvimento , Regulação Enzimológica da Expressão Gênica , Regulação da Expressão Gênica de Plantas , Glucanos/química , Glucanos/metabolismo , Glicosiltransferases/química , Glicosiltransferases/genética , Concentração de Íons de Hidrogênio , Hidrolases/química , Hidrolases/genética , Cinética , Modelos Moleculares , Proteínas de Plantas/química , Proteínas de Plantas/genética , Ligação Proteica , Domínios Proteicos , Temperatura , Xilanos/química , Xilanos/metabolismo
11.
Plants (Basel) ; 9(4)2020 Apr 02.
Artigo em Inglês | MEDLINE | ID: mdl-32252456

RESUMO

Several attempts have been made to study the effects of methyl jasmonate (MeJA) on plants in the past years. However, the comparative effects of the number and phenological time of MeJA applications on the activation of defense systems is currently unknown in strawberries. In the present research, we performed three field treatments during strawberry (Fragaria× ananassa 'Camarosa') fruit development and ripening which consisted of differential MeJA applications at flowering (M3), and the large green (M2 and M3) and red ripe (M1, M2, and M3) fruit stages. We also checked changes in gene expression related to plant defense against Botrytis cinerea inoculation post-harvest. In M3 treatment, we observed an upregulation of the anthocyanin and lignin contents and the defense-related genes, encoding for chitinases, ß-1,3-glucanases and polygalacturonase-inhibiting proteins, after harvest (0 hpi), along with the jasmonate signaling-related genes FaMYC2 and FaJAZ1 at 48 h after B. cinerea inoculation (48 hpi) during postharvest storage. Although we did not find differences in gray mold incidence between the MeJA treatments and control, these results suggest that preharvest MeJA treatment from the flowering stage onwards (M3) primes defense responses mediated by the upregulation of different defense-related genes and retains the upregulation of MYC2 and JAZ1 at 48 hpi.

12.
Molecules ; 24(19)2019 Sep 26.
Artigo em Inglês | MEDLINE | ID: mdl-31561437

RESUMO

The bacterial resistance to antibiotics has compromised the therapies used for bacterial infections. Nowadays, many strategies are being carried out to address this problem. Among them, the use of natural compounds like cinnamic and p-coumaric acids stands out. Nevertheless, their utilization is limited because of their unfavorable physicochemical properties. Due to the lack of new therapeutic alternatives for bacterial infections, novel strategies have emerged, such as the use of ionic liquids; given that they can show a broad spectrum of antibacterial activity, this is why we herein report the antibacterial and antibiofilm activity of a series of N-alkylimidazolium salts functionalized with p-coumaric and cinnamic acids. The results from this study showed better antibacterial activity against Gram-positive bacteria, with a predominance of the salts derived from coumaric acid and a correlation with the chain length. Additionally, a lower efficacy was observed in the inhibition of biofilm formation, highlighting the antibiofilm activity against Staphylococcus aureus, which decreased the production of the biofilm by 52% over the control. In conclusion, we suggest that the salts derived from p-coumaric acid are good alternatives as antibacterial compounds. Meanwhile, the salt derived from cinnamic acid could be a good alternative as an antibiofilm compound.


Assuntos
Anti-Infecciosos/química , Anti-Infecciosos/farmacologia , Biofilmes/efeitos dos fármacos , Cinamatos/química , Imidazóis/química , Imidazóis/farmacologia , Propionatos/química , Ácidos Cumáricos , Líquidos Iônicos , Testes de Sensibilidade Microbiana , Conformação Molecular , Simulação de Dinâmica Molecular , Relação Estrutura-Atividade
13.
Biomed Res Int ; 2019: 9165648, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31240229

RESUMO

Inflammation is a consequence of an array of biological reactions that occur in response to pain sensation, local injury, and cell damage. A large number of studies have demonstrated that quercetin and other flavonoids show anti-inflammatory effects; thus, in the present work, we evaluated a triazine-phenol derivative (TP derivative) compound as a possible drug candidate with anti-inflammatory activity. This compound was studied as a possible anti-inflammatory drug using synthesis and characterization by Fourier transform infrared spectroscopy (FTIR), thermogravimetric analysis (TGA), and mass spectrometry (MS). The derivative of melamine was evaluated for its antioxidant activity and exhibited good DPPH and FRAP antioxidant activity. Additionally, we evaluated the putative effect of the molecule on the COX-2 enzyme through molecular dynamic simulation (MDS), and the result suggested that the TP derivative is a potential anti-inflammatory agent that can interact with the COX-2 enzyme because of the high number of protein-ligand interactions observed with MDS. Finally, the study of theoretical physicochemical properties, the observation of low toxicity (hemolysis assay), and the evaluation of oral bioavailability of the TP derivative showed that it is a possible anti-inflammatory drug candidate.


Assuntos
Anti-Inflamatórios/farmacologia , Antioxidantes/análise , Antioxidantes/química , Triazinas/análise , Triazinas/química , Compostos de Bifenilo , Simulação por Computador , Ciclo-Oxigenase 2/química , Eritrócitos , Flavonoides/farmacologia , Hemólise , Técnicas In Vitro , Inflamação , Ligantes , Simulação de Acoplamento Molecular , Fenol/farmacologia , Picratos , Quercetina/farmacologia
14.
Plants (Basel) ; 8(6)2019 May 28.
Artigo em Inglês | MEDLINE | ID: mdl-31141938

RESUMO

The endo-ß-1,4-glucanases (EGs) that belong to the glycosyl hydrolase family 9 (GH9) have roles in cell wall synthesis, remodeling and degradation. Previous studies have suggested that EGs may play a key role in the ripening of different fruits including strawberries. In this study, we used reverse-transcription quantitative polymerase chain reaction (RT-qPCR) assays to determine the transcript accumulation of an endo-ß-1,4-glucanase (FaEG1) during fruit development in two different strawberry 'Camarosa' and 'Monterey' with contrasting softening ratios. Phylogenetic analyses suggest that FaEG1 belongs to the α group of the GH9 family with other proteins previously described with roles in elongation, abscission and ripening. Comparative modeling was used to obtain the FaEG1 structure. The model displays a α-barrel-type structure that is typical of the GH9 enzyme family, and comprises 12 α-helices, 2 310 helices and 6 ß-sheets. The catalytic residues were oriented to the solvent in the middle of an open groove. Protein-ligand interactions were explored with cellulose and two xyloglucans as ligands; the results suggest that the FaEG1-cellulose and FaEG1-XXXGXXXG (the most abundant xyloglucan in strawberries) complexes were more stable complexes than XXFGXXFG. The cell wall degradation was observed by scanning electron microscopy (SEM). The data are congruent with the probable role of the FaEG1 protein in the dissembly of the cellulose-hemicellulose fraction during the ripening of strawberry fruit.

15.
Food Res Int ; 119: 769-776, 2019 05.
Artigo em Inglês | MEDLINE | ID: mdl-30884715

RESUMO

Since an intake of fruits and vegetables displays important effects on the incidence of several chronic and non-infectious diseases in humans, consumers' attention worldwide is focused on identification of functional foods. In this sense, Fragaria chiloensis ssp. chiloensis f. chiloensis fruit has recently emerged as a preferred berry because of its outstanding aroma and exotic white-pink color and high phenolic content. Emerging research provides substantial evidence by which to classify Chilean strawberries as a functional food with several preventive and therapeutic health benefits. Information on the features of the fruit (e.g., quality, physiology, high resistance to pathogens, and sensory attributes) is also scarce. Only a small number of studies provide useful data on handling and storage of the Chilean strawberry; hence, there is no adequate, normalized postharvest strategy for storing and/or producing this species. The objective of this review is to provide and discuss the available literature with an emphasis on physiology aspects and to present 1) fruit physiology and quality, 2) handling and physiological disorders of Chilean strawberry, 3) nutritional content and health properties for consumers, and 4) a highlight of challenges for future research. Again, we discuss the available literature focused on last five-years old with an emphasis on the important postharvest physiology aspects and the molecular mechanisms underlying the quality traits of this exotic strawberry fruit.


Assuntos
Fragaria/química , Frutas/química , Valor Nutritivo , Antocianinas/análise , Pré-Escolar , Chile , Frutas/fisiologia , Alimento Funcional , Hormônios , Humanos , Odorantes/análise , Fenóis/análise , Pigmentos Biológicos , Fatores de Transcrição
16.
Plant Physiol Biochem ; 136: 155-161, 2019 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-30684844

RESUMO

Xyloglucan endotransglycosylase/hydrolases (XTH) may have endotransglycosylase (XET) and/or hydrolase (XEH) activities. Previous studies confirmed XET activity for PrXTH1 protein from radiata pine. XTHs could interact with many hemicellulose substrates, but the favorite substrate of PrXTH1 is still unknown. The prediction of union type and energy stability of the complexes formed between PrXTH1 and different substrates (XXXGXXXG, XXFGXXFG, XLFGXLFG and cellulose) were determined using bioinformatics tools. Molecular Docking, Molecular Dynamics, MM-GBSA and Electrostatic Potential Calculations were employed to predict the binding modes, free energies of interaction and the distribution of electrostatic charge. The results suggest that the enzyme formed more stable complexes with hemicellulose substrates than cellulose, and the best ligand was the xyloglucan XLFGXLFG (free energy of -58.83 ±â€¯0.8 kcal mol-1). During molecular dynamics trajectories, hemicellulose fibers showed greater stability than cellulose. Aditionally, the kinetic properties of PrXTH1 enzyme were determined. The recombinant protein was active and showed an optimal pH 5.0 and optimal temperature of 37 °C. A Km value of 20.9 mM was determined for xyloglucan oligomer. PrXTH1 is able to interact with different xyloglycans structures but no activity was observed for cellulose as substrate, remodeling cell wall structure in response to inclination.


Assuntos
Glicosiltransferases/metabolismo , Pichia/fisiologia , Proteínas de Plantas/metabolismo , Parede Celular/metabolismo , Clonagem Molecular , Regulação da Expressão Gênica de Plantas/fisiologia , Glicosiltransferases/fisiologia , Cinética , Simulação de Acoplamento Molecular , Pichia/enzimologia , Pichia/metabolismo , Proteínas de Plantas/fisiologia , Proteínas Recombinantes , Especificidade por Substrato
17.
J Biomol Struct Dyn ; 37(12): 3245-3258, 2019 08.
Artigo em Inglês | MEDLINE | ID: mdl-30175949

RESUMO

Expansins are cell wall proteins associated with several processes, including changes in the cell wall during ripening of fruit, which matches softening of the fruit. We have previously reported an increase in expression of specific expansins transcripts during softening of Fragaria chiloensis fruit. Here, we characterized three α-expansins. Their full-length sequences were obtained, and through qRT-PCR (real-time PCR) analyses, their transcript accumulation during softening of F. chiloensis fruit was confirmed. Interestingly, differential but overlapping expression patterns were observed. With the aim of elucidating their roles, 3D protein models were built using comparative modeling methodology. The models obtained were similar and displayed cellulose binding module(CBM ) with a ß-sandwich structure, and a catalytic domain comparable to the catalytic core of protein of the family 45 glycosyl hydrolase. An open groove located at the central part of each expansin was described; however, the shape and size are different. Their protein-ligand interactions were evaluated, showing favorable binding affinity energies with xyloglucan, homogalacturonan, and cellulose, cellulose being the best ligand. However, small differences were observed between the protein-ligand conformations. Molecular mechanics-generalized Born-surface area (MM-GBSA) analyses indicate the major contribution of van der Waals forces and non-polar interactions. The data provide a dynamic view of interaction between expansins and cellulose as putative cell wall ligands at the molecular scale. Communicated by Ramaswamy H. Sarma.


Assuntos
Fragaria/química , Frutas/química , Proteínas de Plantas/química , Parede Celular/química , Celulose/química , Regulação da Expressão Gênica de Plantas/fisiologia , Glucanos/química , Ligantes , Simulação de Dinâmica Molecular , Pectinas/química , Conformação Proteica , Xilanos/química
18.
Plant Physiol Biochem ; 135: 215-223, 2019 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-30576980

RESUMO

Plants respond to the loss of vertical growth re-orientating their affected organs. In trees, this phenomenon has received the scientific attention due to its importance for the forestry industry. Nowadays it is accepted that auxin distribution is involved in the modulation of the tilting response, but how this distribution is controlled is not fully clear. Auxin transporters that determine the spatio-temporal auxin distribution in radiate pine seedlings exposed to 45° of tilting were identified. Additionally, based on indications for an intimate plant hormone crosstalk in this process, IAA and JA contents were evaluated. The experiments revealed that expression of the auxin transporters was down-regulated in the upper half of the tilted stem, while being induced in the lower half. Moreover, transporter-coding genes were first induced at the apical zone of the stem. IAA was consistently redistributed toward the lower half, which is in accordance with the expression profile of the auxin transporters. In contrast, JA was mainly accumulated in the upper half of tilted stems. Finally, lignin content and monomeric composition were analyzed in both sides of stem and along the time course of tilting. As expected, lignin accumulation was higher at the lower half of stem at longer times of tilting. However, the most marked difference was the accumulation of the H-lignin monomer in the lower half, while the G-lignin unit was more dominant in the upper half. Here, we provide detailed insight in the distribution of IAA and JA, affecting the lignin composition during the tilting response in Pinus radiata seedlings.


Assuntos
Ciclopentanos/metabolismo , Ácidos Indolacéticos/metabolismo , Lignina/biossíntese , Oxilipinas/metabolismo , Pinus/metabolismo , Reguladores de Crescimento de Plantas/metabolismo , Caules de Planta/metabolismo , Plântula/metabolismo , Regulação da Expressão Gênica de Plantas , Filogenia , Pinus/genética , Pinus/crescimento & desenvolvimento , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Reação em Cadeia da Polimerase em Tempo Real , Plântula/crescimento & desenvolvimento , Análise de Sequência de DNA
19.
J Mol Graph Model ; 85: 250-261, 2018 10.
Artigo em Inglês | MEDLINE | ID: mdl-30243225

RESUMO

The phytohormone jasmonoyl-isoleucine (JA-Ile) regulates fundamental plant processes. Fragaria vesca, the woodland strawberry, is a model plant for the Rosaceae family, in which the JA-Ile perception is poorly understood at the molecular level. JA-Ile promotes binding of JAZ repressor to COI1 protein in Arabidopsis to activate jasmonate (JA)-dependent responses. The aim of this work was to understand the molecular basis of the interaction between the F. vesca COI1 (FvCOI1) and JAZ1 (FvJAZ1) promoted by JA-Ile using a computational approach. Multiple sequence alignments and phylogenetic analyses of amino acid sequences were performed for FvCOI1, FvJAZ1 and their ortholog sequences. 3D structures for FvCOI1 and FvJAZ1 proteins were built by methods of homology modeling, using AtCOI1-JA-Ile-AtJAZ1 as template and then they were further refined and validated by molecular dynamics (MD) simulation. A molecular docking approach along with MDS analysis were used to gain insights into the interaction between a putative degron-like sequence present in FvJAZ1 with the FvCOI1-JA-Ile complex. FvCOI1 and FvJAZ1 showed high and moderate sequence identity, respectively, with the corresponding ortholog proteins from other plant species including apple, grape, tomato and Arabidopsis. Moreover, the FvJAZ1 has a variant C-terminal IPMQRK sequence instead of the canonical LPIARR degron sequence located in the Jas domain of AtJAZ1. The MD simulation results showed that the FvCOI1-JA-Ile-FvJAZ1 complex was stable, and the IPMQRK peptide of FvJAZ1 directly interacted with FvCOI1 and JA-Ile. The present research provides novel insight into the molecular interactions among key JA-signaling components in the model plant F. vesca, being few examples of characterized JA-Ile receptors at a structural level in plants.


Assuntos
Ciclopentanos/química , Fragaria/genética , Isoleucina/análogos & derivados , Reguladores de Crescimento de Plantas/química , Reguladores de Crescimento de Plantas/genética , Proteínas de Plantas/química , Proteínas de Plantas/genética , Sequência de Aminoácidos , Ciclopentanos/metabolismo , Fragaria/metabolismo , Isoleucina/química , Isoleucina/genética , Isoleucina/metabolismo , Ligantes , Modelos Moleculares , Conformação Molecular , Complexos Multiproteicos/química , Reguladores de Crescimento de Plantas/metabolismo , Proteínas de Plantas/metabolismo , Ligação Proteica , Domínios e Motivos de Interação entre Proteínas , Análise de Sequência de DNA , Relação Estrutura-Atividade
20.
Comput Biol Chem ; 76: 79-86, 2018 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-29982166

RESUMO

Changes in the cellulose-hemicellulose fraction take place during ripening of strawberry fruit and are associated with the activity of a set of proteins and hydrolytic enzymes. Expansins are proteins located in the cell wall with no catalytic activity. In this context, FaEXPA1 was previously reported to have a high accumulation rate during fruit ripening in three different strawberry cultivars. In order to understand at the molecular level the expansin mechanism mode, a 3D model of FaEXPA1 protein was built by comparative modeling. FaEXPA1 protein model displayed two domains, a cellulose-binding domain with a ß-sandwich structure, and a second domain that included a HFD motif with a similar structure to the catalytic core of endoglucanase V from Humicola insolens. Additionally, in the center of the structure, an open groove was formed. Finally, using a cellulose polymer as a ligand, the protein-ligand interaction was evaluated by molecular dynamic (MD) simulation. Two MD simulations showed that FaEXPA1 can interact with cellulose via the flat aromatic surface of its binding domain D2, composed mainly of residues Trp99 and Trp225. In addition, FaEXPA1 formed a high number of hydrogen bonds with the glycan chain and the Asn81, Phe114 and Asn211 residues.


Assuntos
Celulose/metabolismo , Proteínas de Plantas/metabolismo , Sequência de Aminoácidos , Sítios de Ligação , Celulose/química , Fragaria/química , Ligação de Hidrogênio , Ligantes , Simulação de Dinâmica Molecular , Mutação , Proteínas de Plantas/química , Proteínas de Plantas/genética , Ligação Proteica
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