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1.
Gels ; 10(3)2024 Mar 08.
Artigo em Inglês | MEDLINE | ID: mdl-38534603

RESUMO

The integration of abscisic acid (ABA) into a chitosan-alginate gel blend unveils crucial insights into the formation and stability of these two substances. ABA, a key phytohormone in plant growth and stress responses, is strategically targeted for controlled release within these complexes. This study investigates the design and characterization of this novel controlled-release system, showcasing the potential of alginate-chitosan gel blends in ABA delivery. Computational methods, including molecular dynamics simulations, are employed to analyze the structural effects of microencapsulation, offering valuable insights into complex behavior under varying conditions. This paper focuses on the controlled release of ABA from these complexes, highlighting its strategic importance in drug delivery systems and beyond. This controlled release enables targeted and regulated ABA delivery, with far-reaching implications for pharmaceuticals, agriculture, and plant stress response studies. While acknowledging context dependency, the paper suggests that the liberation or controlled release of ABA holds promise in applications, urging further research and experimentation to validate its utility across diverse fields. Overall, this work significantly contributes to understanding the characteristics and potential applications of chitosan-alginate complexes, marking a noteworthy advancement in the field of controlled-release systems.

2.
Plant Physiol Biochem ; 207: 108417, 2024 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-38354527

RESUMO

Strawberry is one of the most popular fruits in the world, because their high fruit quality, especially with respect to the combination of aroma, flavor, color, and nutritional compounds. Pyruvate decarboxylase (PDC) is the first of two enzymes specifically required for ethanolic fermentation and catalyzes the decarboxylation of pyruvate to yield acetaldehyde and CO2. The ethanol, an important alcohol which acts as a precursor for the ester and other alcohols formation in strawberry, is produced by the PDC. The objective was found all different PDCs genes present in the strawberry genome and investigate PDC gene expression and ligand-protein interactions in strawberry fruit. Volatile organic compounds were evaluated during the development of the fruit. After this, eight FaPDC were identified with four genes that increase the relative expression during fruit ripening process. Molecular dynamics simulations were performed to analyze the behavior of Pyr and TPP ligands within the catalytic and regulatory sites of the PDC proteins. Results indicated that energy-restrained simulations exhibited minor fluctuations in ligand-protein interactions, while unrestrained simulations revealed crucial insights into ligand affinity. TPP consistently displayed strong interactions with the catalytic site, emphasizing its pivotal role in enzymatic activity. However, FaPDC6 and FaPDC9 exhibited decreased pyruvate affinity initially, suggesting unique binding characteristics requiring further investigation. Finally, the present study contributes significantly to understanding PDC gene expression and the intricate molecular dynamics underlying strawberry fruit ripening, shedding light on potential targets for further research in this critical biological pathway.


Assuntos
Fragaria , Piruvato Descarboxilase , Piruvato Descarboxilase/genética , Piruvato Descarboxilase/metabolismo , Fragaria/genética , Fragaria/metabolismo , Frutas/metabolismo , Ligantes , Proteínas de Plantas/metabolismo , Etanol/metabolismo , Piruvatos/metabolismo , Regulação da Expressão Gênica de Plantas
3.
Polymers (Basel) ; 15(15)2023 Jul 28.
Artigo em Inglês | MEDLINE | ID: mdl-37571107

RESUMO

Abscisic acid (ABA) has been proposed to play a significant role in the ripening of nonclimacteric fruit, stomatal opening, and response to abiotic stresses in plants, which can adversely affect crop growth and productivity. The biological effects of ABA are dependent on its concentration and signal transduction pathways. However, due to its susceptibility to the environment, it is essential to find a suitable biotechnological approach to coat ABA for its application. One promising approach is to utilize alginate and chitosan, two natural polysaccharides known for their strong affinity for water and their ability to act as coating agents. In this study, an alginate-chitosan blend was employed to develop an ABA cover. To achieve this, an alginate-chitosan-abscisic acid (ALG-CS-ABA) blend was prepared by forming ionic bonds or complexes with calcium ions, or through dual cross-linking. This was done by dripping a homogeneous solution of alginate-chitosan and ABA into a calcium chloride solution, resulting in the formation of the blend. By combining the unique properties of alginate, chitosan, and ABA, the resulting ALG-CS-ABA blend can potentially offer enhanced stability, controlled release, and improved protection of ABA. These characteristics make it a promising biotechnological approach for various applications, including the targeted delivery of ABA in agricultural practices or in the development of innovative plant-based products. Further evaluation and characterization of the ALG-CS-ABA blend will provide valuable insights into its potential applications in the fields of biomedicine, agriculture, and tissue engineering.

4.
Polymers (Basel) ; 15(14)2023 Jul 12.
Artigo em Inglês | MEDLINE | ID: mdl-37514411

RESUMO

Pesticides have a significant negative impact on the environment, non-target organisms, and human health. To address these issues, sustainable pest management practices and government regulations are necessary. However, biotechnology can provide additional solutions, such as the use of polyelectrolyte complexes to encapsulate and remove pesticides from water sources. We introduce a computational methodology to evaluate the capture capabilities of Calcium-Alginate-Chitosan (CAC) nanoparticles for a broad range of pesticides. By employing ensemble-docking and molecular dynamics simulations, we investigate the intermolecular interactions and absorption/adsorption characteristics between the CAC nanoparticles and selected pesticides. Our findings reveal that charged pesticide molecules exhibit more than double capture rates compared to neutral counterparts, owing to their stronger affinity for the CAC nanoparticles. Non-covalent interactions, such as van der Waals forces, π-π stacking, and hydrogen bonds, are identified as key factors which stabilized the capture and physisorption of pesticides. Density profile analysis confirms the localization of pesticides adsorbed onto the surface or absorbed into the polymer matrix, depending on their chemical nature. The mobility and diffusion behavior of captured compounds within the nanoparticle matrix is assessed using mean square displacement and diffusion coefficients. Compounds with high capture levels exhibit limited mobility, indicative of effective absorption and adsorption. Intermolecular interaction analysis highlights the significance of hydrogen bonds and electrostatic interactions in the pesticide-polymer association. Notably, two promising candidates, an antibiotic derived from tetracycline and a rodenticide, demonstrate a strong affinity for CAC nanoparticles. This computational methodology offers a reliable and efficient screening approach for identifying effective pesticide capture agents, contributing to the development of eco-friendly strategies for pesticide removal.

5.
Comput Biol Chem ; 106: 107932, 2023 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-37487249

RESUMO

Lipopeptides are medicinally essential building blocks with strong hemolytic, antifungal and antibiotic potential. In the present research article, we are presenting our findings regarding the synthesis of N-alkylated lipopeptides via Ugi four-component approach, their antimicrobial potential against pathogenic (Gram-positive and Gram-negative) bacteria, as well as computational studies to investigate the compounds binding affinity and dynamic behavior with MurD antibacterial target. Molecular docking demonstrated the compounds have good binding ability with MurD enzyme. The FT94, FT95 and FT97 compounds revealed binding affinity scores of -8.585 kcal mol- 1, -7.660 kcal mol- 1 and -7.351 kcal mol- 1, respectively. Furthermore, dynamics analysis pointed the systems high structure dynamics. The docking and simulation results were validated by binding free energies, demonstrating solid intermolecular interactions and in the assay in vitro, the Minimal Inhibitory Concentration (MIC) of FT97 to Staphylococcus aureus (S. aureus) was 62.5 µg/mL. In conclusion, a moderate inhibitory response of peptoid FT97 was observed against the Gram-positive bacteria, S. aureus and B. cereus.


Assuntos
Anti-Infecciosos , Staphylococcus aureus , Simulação de Acoplamento Molecular , Antibacterianos/farmacologia , Lipopeptídeos/farmacologia
6.
Plant Mol Biol ; 112(3): 107-117, 2023 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-37178231

RESUMO

Cell wall is a strong and complex net whose function is to provide turgor, pathogens attack protection and to give structural support to the cell. In growing and expanding cells, the cell wall of fruits is changing in space and time, because they are changing according to stage of ripening. Understand which mechanisms to produce significant could help to develop tools to prolong the fruit shelf life. Cell wall proteins (CWPs) with enzymatic activity on cell wall polysaccharides, have been studied widely. Another investigations take place in the study of N-glycosylations of CWPs and enzymes with activity on glycosidic linkages. α-mannosidase (α-Man; EC 3.2.1.24) and ß-D-N-acetylhexosaminidase (ß-Hex; EC 3.2.1.52), are enzymes with activity on mannose and N-acetylglucosamine sugar presents in proteins as part of N-glycosylations. Experimental evidence indicate that both are closely related to loss of fruit firmness, but in the literature, there is still no review of both enzymes involved fruit ripening. This review provides a complete state-of-the-art of α-Man and ß-Hex enzymes related in fruit ripening. Also, we propose a vesicular α-Man (EC 3.2.1.24) name to α-Man involved in N-deglycosylations of CWPs of plants.


Assuntos
Frutas , Glicosídeo Hidrolases , alfa-Manosidase/metabolismo , Glicosídeo Hidrolases/metabolismo , Frutas/metabolismo , Polissacarídeos/metabolismo , Proteínas de Plantas/metabolismo , Parede Celular/metabolismo
7.
J Mol Graph Model ; 122: 108502, 2023 07.
Artigo em Inglês | MEDLINE | ID: mdl-37116336

RESUMO

Polygalacturonase (PG) is an important hydrolytic enzyme involved in pectin disassembly and the subsequent textural changes during fruit ripening. Although the interaction of fungal PGs with other proteins has been documented, the interaction of plant PGs with other plant proteins has not yet been studied. In this study, the molecular mechanisms involved in raspberry fruit ripening, particularly the polygalacturonase (RiPG) interaction with polygalacturonase inhibiting protein (RiPGIP) and substrate, were investigated with a structural approach. The 3D model of RiPG2 and RiPGIP3 was built using a comparative modeling strategy and validated using molecular dynamics (MD) simulations. The RiPG2 model structure comprises 11 complete coils of right-handed parallel ß-helix architecture, with an average of 27 amino acid residues per turn. The structural model of the RiPGIP3 displays a typical structure of LRR protein, with the right-handed superhelical fold with an extended parallel ß-sheet. The conformational interaction between the RiPG2 protein and RiPGIP3 showed that RiPGIP3 could bind to the enzyme and thereby leave the active site cleft accessible to the substrate. All this evidence indicates that RiPG2 enzyme could interact with RiPGIP3 protein. It can be a helpful model for evaluating protein-protein interaction as a potential regulator mechanism of hydrolase activity during pectin disassembly in fruit ripening.


Assuntos
Poligalacturonase , Rubus , Poligalacturonase/química , Poligalacturonase/metabolismo , Rubus/metabolismo , Simulação de Dinâmica Molecular , Frutas/metabolismo , Pectinas/metabolismo , Proteínas de Plantas/metabolismo
8.
Food Res Int ; 161: 111850, 2022 11.
Artigo em Inglês | MEDLINE | ID: mdl-36192976

RESUMO

Climate change is threatening human activities, but the combination of water scarcity and heat waves are particularly challenging agriculture. Accumulating literature shows that beneficial fungal endophytes improve plant performance, a condition that seems to be magnified in presence of stress. Because evidence points out to an endophytic mediation of antioxidant activity in plants, we here focused on flavonoids for two main reasons: (i) they are involved in plant tolerance to abiotic stress, and (ii) they are known to be healthy for human consumption. With these two premises as guidance, we explored the literature trying to link mechanistically the relationship between endophytes and plant responses to stress as well as identifying patterns and knowledge gaps. Overall, fungal endophytes improve plant growth and tolerance to environmental stresses. However, evidence for endophytes boosting flavonoid mediated responses in plants is relatively scarce. Reports showing endophytes promoting flavonoid contents in grains and fresh fruits are rather limited which may be related to (long) length of the required experiments for testing it. The use of endophytes isolated from extreme environments (e.g., dry and cold deserts, acid lakes, etc.) is proposed to be better in conferring tolerance to plants under very stressful conditions. However, the real challenge is to test the capacity of these endophytes to established and maintain persistent and functional symbiosis under productive conditions. In summary, there is a clear potential for symbiotically modifying crop plants as a strategy to develop more tolerant varieties to face the stress and eventually increase the quality of the agricultural products.


Assuntos
Antioxidantes , Flavonoides , Endófitos/fisiologia , Humanos , Valor Nutritivo , Plantas , Simbiose
9.
Front Microbiol ; 13: 939955, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-36090118

RESUMO

Strawberry is one of the most widely consumed fruit, but this crop is highly susceptible to drought, a condition strongly associated with climate change, causing economic losses due to the lower product quality. In this context, plant root-associated fungi emerge as a new and novel strategy to improve crop performance under water-deficiency stress. This study aimed to investigate the supplementation of two Antarctic vascular plant-associated fungal endophytes, Penicillium brevicompactum and Penicillium chrysogenum, in strawberry plants to develop an efficient, effective, and ecologically sustainable approach for the improvement of plant performance under drought stress. The symbiotic association of fungal endophytes with strawberry roots resulted in a greater shoot and root biomass production, higher fruit number, and an enhanced plant survival rate under water-limiting conditions. Inoculation with fungal endophytes provokes higher photosynthetic efficiency, lower lipid peroxidation, a modulation in antioxidant enzymatic activity, and increased proline content in strawberry plants under drought stress. In conclusion, promoting beneficial symbiosis between plants and endophytes can be an eco-friendly strategy to cope with drought and help to mitigate the impact of diverse negative effects of climate change on crop production.

10.
Int J Mol Sci ; 23(10)2022 May 20.
Artigo em Inglês | MEDLINE | ID: mdl-35628551

RESUMO

Deschampsia antarctica Desv. (Poaceae) is one of the two vascular plants that have colonized the Antarctic Peninsula, which is usually exposed to extreme environmental conditions. To support these conditions, the plant carries out modifications in its morphology and metabolism, such as modifications to the cell wall. Thus, we performed a comparative study of the changes in the physiological properties of the cell-wall-associated polysaccharide contents of aerial and root tissues of the D. antarctica via thermogravimetric analysis (TGA) combined with a computational approach. The result showed that the thermal stability was lower in aerial tissues with respect to the root samples, while the DTG curve describes four maximum peaks of degradation, which occurred between 282 and 358 °C. The carbohydrate polymers present in the cell wall have been depolymerized showing mainly cellulose and hemicellulose fragments. Additionally, a differentially expressed sequence encoding for an expansin-like (DaEXLA2), which is characterized by possessing cell wall remodeling function, was found in D. antarctica. To gain deep insight into a probable mechanism of action of the expansin protein identified, a comparative model of the structure was carried out. DaEXLA2 protein model displayed two domains with an open groove in the center. Finally, using a cell wall polymer component as a ligand, the protein-ligand interaction was evaluated by molecular dynamic (MD) simulation. The MD simulations showed that DaEXLA2 could interact with cellulose and XXXGXXXG polymers. Finally, the cell wall component description provides the basis for a model for understanding the changes in the cell wall polymers in response to extreme environmental conditions.


Assuntos
Parede Celular , Poaceae , Celulose/química , Ligantes , Simulação de Dinâmica Molecular , Poaceae/fisiologia
11.
Biomed Res Int ; 2022: 5576090, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35463991

RESUMO

Reduced glutathione (GSH) has a high antioxidant capacity and is present in nearly every cell in the body, playing important roles in nutrient metabolism, antioxidant defense, and regulation of cellular events. Conversely, alginate is a macromolecule that has been widely used in the food, pharmaceutical, biomedical, and textile industries due to its biocompatibility, biodegradability, nontoxicity, and nonimmunogenicity as well as for its capabilities of retaining water and stabilizing emulsions. The primary goal of this study was to characterize and optimize the formation of a molecular complex of calcium alginate with GSH using a computational approach. As methods, we evaluated the influence of varying the amount of calcium cations at two different pHs on the structural stability of Ca2+-alginate complexes and thus on GSH liberation from these types of nanostructures. The results showed that complex stabilization depends on pH, with the system having a lower Ca2+ amount that produces the major GSH release. The systems at pH 2.5 retain more molecules within the calcium-alginate complex, which release GSH more slowly when embedded in more acidic media. In conclusions, this study demonstrates the dependence of the amount of calcium and the stabilizing effect of pH on the formation and subsequent maintenance of an alginate nanostructure. The results presented in this study can help to develop better methodological frameworks in industries where the release or capture of compounds, such as GSH in this case, depends on the conditions of the alginate nanoparticle.


Assuntos
Alginatos , Polímeros , Alginatos/química , Antioxidantes , Cálcio , Ácido Glucurônico/química , Glutationa , Ácidos Hexurônicos/química , Polímeros/química
12.
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.


Assuntos
Cycadopsida/crescimento & desenvolvimento , Flavonoides/metabolismo , Reguladores de Crescimento de Plantas/metabolismo , Cycadopsida/metabolismo , Homeostase , Lignina/biossíntese
13.
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.


Assuntos
Caryophyllaceae , Fungos não Classificados , Regiões Antárticas , Secas , Endófitos , Proteínas de Plantas/genética
14.
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
15.
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 Gênica/efeitos dos fármacos , Ácidos Tri-Iodobenzoicos/farmacologia
16.
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.

17.
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
18.
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
19.
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
20.
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.

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