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1.
Proc Natl Acad Sci U S A ; 120(4): e2209480119, 2023 01 24.
Artigo em Inglês | MEDLINE | ID: mdl-36649403

RESUMO

Around 10,000 y ago in southwest Asia, the cessation of a mobile lifestyle and the emergence of the first village communities during the Neolithic marked a fundamental change in human history. The first communities were small (tens to hundreds of individuals) but remained semisedentary. So-called megasites appeared soon after, occupied by thousands of more sedentary inhabitants. Accompanying this shift, the material culture and ancient ecological data indicate profound changes in economic and social behavior. A shift from residential to logistical mobility and increasing population size are clear and can be explained by either changes in fertility and/or aggregation of local groups. However, as sedentism increased, small early communities likely risked inbreeding without maintaining or establishing exogamous relationships typical of hunter-gatherers. Megasites, where large populations would have made endogamy sustainable, could have avoided this risk. To examine the role of kinship practices in the rise of megasites, we measured strontium and oxygen isotopes in tooth enamel from 99 individuals buried at Pinarbasi, Boncuklu, and Çatalhöyük (Turkey) over 7,000 y. These sites are geographically proximate and, critically, span both early sedentary behaviors (Pinarbasi and Boncuklu) and the rise of a local megasite (Çatalhöyük). Our data are consistent with the presence of only local individuals at Pinarbasi and Boncuklu, whereas at Çatalhöyük, several nonlocals are present. The Çatalhöyük data stand in contrast to other megasites where bioarchaeological evidence has pointed to strict endogamy. These different kinship behaviors suggest that megasites may have arisen by employing unique, community-specific kinship practices.


Assuntos
Estilo de Vida , Comportamento Social , Humanos , História Antiga , Turquia , Estrôncio , Comportamento Sedentário
2.
New Phytol ; 2024 Jul 26.
Artigo em Inglês | MEDLINE | ID: mdl-39061101

RESUMO

The plant cuticle is located at the interface of the plant with the environment, thus acting as a protective barrier against biotic and abiotic external stress factors, and regulating water loss. Additionally, it modulates mechanical stresses derived from internal tissues and also from the environment. Recent advances in the understanding of the hydric, mechanical, thermal, and, to a lower extent, optical and electric properties of the cuticle, as well as their phenomenological connections and relationships are reviewed. An equilibrium based on the interaction among the different biophysical properties is essential to ensure plant growth and development. The notable variability reported in cuticle geometry, surface topography, and microchemistry affects the analysis of some biophysical properties of the cuticle. This review aimed to provide an updated view of the plant cuticle, understood as a modification of the cell wall, in order to establish the state-of-the-art biophysics of the plant cuticle, and to serve as an inspiration for future research in the field.

3.
Plant Physiol ; 191(1): 219-232, 2023 01 02.
Artigo em Inglês | MEDLINE | ID: mdl-35972400

RESUMO

The cuticle is a protective extracellular matrix that covers the above-ground epidermis of land plants. Here, we studied the cuticle of tomato (Solanum lycopersicum L.) fruits in situ using confocal Raman microscopy. Microsections from cuticles isolated at different developmental stages were scanned to visualize cuticle components with a spatial resolution of 342 nm by univariate and multivariate data analysis. Three main components, cutin, polysaccharides, and aromatics, were identified, with the latter exhibiting the strongest Raman scattering intensity. Phenolic acids and flavonoids were differentiated within the cuticle, and three schematic cuticle models were identified during development. Phenolic acids were found across the entire cuticle at the earliest stage of development, i.e. during the formation of the procuticle layer. Based on a mixture analysis with reference component spectra, the phenolic acids were identified as mainly esterified p-coumaric acid together with free p-hydroxybenzoic acid. During the cell expansion period of growth, phenolic acids accumulated in an outermost layer of the cuticle and in the middle region of the pegs. In these stages of development, cellulose and pectin were detected next to the inner cuticle region, close to the epidermal cell where flavonoid impregnation started during ripening. In the first ripening stage, chalconaringenin was observed, while methoxylated chalcones were chosen by the algorithm to fit the mature cuticle spectra. The colocation of carbohydrates, esterified p-coumaric acid, and methoxylated chalconaringenin suggests that the latter two link polysaccharide and cutin domains. Elucidating the different distribution of aromatics within the cuticle, suggests important functions: (1) overall impregnation conferring mechanical and thermal functions (2) the outermost phenolic acid layer displaying UV-B protection of the plant tissue.


Assuntos
Solanum lycopersicum , Frutas , Microquímica , Polissacarídeos/análise , Epiderme Vegetal
4.
Phys Chem Chem Phys ; 25(18): 12791-12799, 2023 May 10.
Artigo em Inglês | MEDLINE | ID: mdl-37129056

RESUMO

Coumaric acids and flavonoids play pivotal roles in protecting plants against ultraviolet radiation (UVR) exposure. In this work, we focus our photoprotection studies on p-coumaric acid and the flavonoid naringenin chalcone. Photoprotection is well-understood in p-coumaric acid; in contrast, information surrounding photoprotection in naringenin chalcone is lacking. Additionally, and vitally, how these two species work in unison to provide photoprotection across the UV-B and UV-A is unknown. Herein, we employ transient absorption spectroscopy together with steady-state irradiation studies to unravel the photoprotection mechanism of a solution of p-coumaric acid and naringenin chalcone. We find that the excited state dynamics of p-coumaric acid are significantly altered in the presence of naringenin chalcone. This finding concurs with quenching of the p-coumaric acid fluorescence with increasing concentration of naringenin chalcone. We propose a Förster energy transfer mechanism is operative via the formation of dipole-dipole interactions between p-coumaric acid and naringenin chalcone. To our knowledge, this is the first demonstration in plants of a synergic effect between two classes of phenolics to bypass the potentially damaging effects of UVR.


Assuntos
Frutas , Solanum lycopersicum , Frutas/química , Raios Ultravioleta , Flavonoides/análise , Flavonoides/química , Fenóis , Plantas/química , Análise Espectral
5.
Int J Mol Sci ; 23(9)2022 Apr 22.
Artigo em Inglês | MEDLINE | ID: mdl-35563041

RESUMO

Retrieving high-quality endogenous ancient DNA (aDNA) poses several challenges, including low molecular copy number, high rates of fragmentation, damage at read termini, and potential presence of exogenous contaminant DNA. All these factors complicate a reliable reconstruction of consensus aDNA sequences in reads from high-throughput sequencing platforms. Here, we report findings from a thorough evaluation of two alternative tools (ANGSD and schmutzi) aimed at overcoming these issues and constructing high-quality ancient mitogenomes. Raw genomic data (BAM/FASTQ) from a total of 17 previously published whole ancient human genomes ranging from the 14th to the 7th millennium BCE were retrieved and mitochondrial consensus sequences were reconstructed using different quality filters, with their accuracy measured and compared. Moreover, the influence of different sequence parameters (number of reads, sequenced bases, mean coverage, and rate of deamination and contamination) as predictors of derived sequence quality was evaluated. Complete mitogenomes were successfully reconstructed for all ancient samples, and for the majority of them, filtering substantially improved mtDNA consensus calling and haplogroup prediction. Overall, the schmutzi pipeline, which estimates and takes into consideration exogenous contamination, appeared to have the edge over the much faster and user-friendly alternative method (ANGSD) in moderate to high coverage samples (>1,000,000 reads). ANGSD, however, through its read termini trimming filter, showed better capabilities in calling the consensus sequence from low-quality samples. Among all the predictors of overall sample quality examined, the strongest correlation was found for the available number of sequence reads and bases. In the process, we report a previously unassigned haplogroup (U3b) for an Early Chalcolithic individual from Southern Anatolia/Northern Levant.


Assuntos
DNA Mitocondrial , Genoma Mitocondrial , DNA Antigo , DNA Mitocondrial/genética , Sequenciamento de Nucleotídeos em Larga Escala/métodos , Humanos , Análise de Sequência de DNA/métodos
6.
Plant Physiol ; 183(4): 1622-1637, 2020 08.
Artigo em Inglês | MEDLINE | ID: mdl-32457092

RESUMO

The aerial parts of plants, including the leaves, fruits and non-lignified stems, are covered with a protective cuticle, largely composed of the polyester cutin. Two mechanisms of cutin deposition have been identified in tomato (Solanum lycopersicum) fruit. The contribution of each mechanism to cutin synthesis and deposition has shown a temporal and coordinated sequence that correlates with the two periods of organ growth, cell division and cell expansion. Cutinsomes, self-assembled particles composed of esterified cutin monomers, are involved in the synthesis of the procuticle during cell division and provide a template for further cutin deposition. CUTIN SYNTHASE1 (CUS1), an acyl transferase enzyme that links cutin monomers, contributes to massive cuticle deposition during the early stages of the cell expansion period by incorporating additional cutin to the procuticle template. However, cutin deposition and polymerization appear to be part of a more complex biological scenario, which is yet not fully understood. CUS1 is also associated with the coordinated growth of the cutinized and non-cutinized domains of the outer epidermal wall, and affects cell size. A dynamic and complex interplay linking cutin synthesis with cell wall development and epidermal cell size has been identified.


Assuntos
Frutas/enzimologia , Frutas/metabolismo , Lipídeos de Membrana/metabolismo , Proteínas de Plantas/metabolismo , Solanum lycopersicum/enzimologia , Solanum lycopersicum/metabolismo , Regulação da Expressão Gênica de Plantas
7.
Phys Chem Chem Phys ; 23(33): 18068-18077, 2021 Sep 07.
Artigo em Inglês | MEDLINE | ID: mdl-34388230

RESUMO

In this study, the theoretical and experimental results on the molecular structure and reactivity of the plant flavonoids naringenin chalcone and naringenin are reported. UV-vis and Raman spectra were recorded and their main bands have been assigned theoretically. Moreover, the analysis of the naringenin chalcone-naringenin cyclization-isomerization reaction and the formation of homodimers and heterodimers have been performed within a DFT framework. The presence of H-bonded water networks is mandatory to make the cyclization energetically suitable, suggesting that this equilibrium will occur in an aqueous intracellular environment rather than in the extracellular and hydrophobic plant cuticles. Additionally, the preferential formation of homodimers stabilized by π-π stacking that will interact with other dimers by H-bonding over the formation of naringenin chalcone-naringenin heterodimers is also proposed in a hydrophobic environment. These results give a plausible model to explain how flavonoids are located within the cuticle molecular arrangement.


Assuntos
Flavanonas/química , Teoria da Densidade Funcional , Dimerização , Estrutura Molecular , Estereoisomerismo
8.
Environ Res ; 197: 111021, 2021 06.
Artigo em Inglês | MEDLINE | ID: mdl-33774014

RESUMO

Neonicotinoids sonochemical oxidation at high-frequency ultrasound (MHz range) has been carried out in ultrapure and natural surface-water matrices (river, reservoir and wastewater treatment plant effluent). To evaluate the influence of the operating variables, that is initial pollutant concentration, ultrasound frequency, ultrasound power, and pulse-stop time a Box-Behnken experimental design was planned. Optimal results were obtained using a frequency of 578 kHz, a power of 40 W L-1, with a pollutant concentration of 1 µM (for each pesticide), and using a pulse-stop time of 100 ms. The experimental data adjustment using the Langmuir-Hinshelwood heterogeneous kinetic model showed that neonicotinoids oxidation was carried out in the bubble-liquid interface by the attack of hydroxyl radicals. Experiments performed in the presence of radical scavengers, that is, methanol, ethanol and tert-butyl alcohol corroborated this reaction mechanism. The influence of some environmental conditions such as pH, presence of soluble inorganic species (Cl-, SO42-, NO3-, HPO42-, HCO3-) and soluble organic species (humic acids content) were established. Finally, the aqueous matrix's influence was investigated for three natural surface water cases, and the results were rationalized according to the main water physicochemical characteristics.


Assuntos
Praguicidas , Poluentes Químicos da Água , Purificação da Água , Substâncias Húmicas , Radical Hidroxila , Neonicotinoides , Oxirredução , Poluentes Químicos da Água/análise
9.
Aten Primaria ; 51(4): 236-244, 2019 04.
Artigo em Espanhol | MEDLINE | ID: mdl-29728286

RESUMO

AIM: To evaluate the effectiveness of a 9 months of supervised Physical Activity (PA) Program with sociocultural activities, on self-esteem and its association on the control of chronic diseases in adult primary care users. DESIGN: Multicenter, randomized, controlled community intervention. LOCATION: 4 Primary care centers in Reus-Tarragona, Spain. PARTICIPANTS: 364 subjects, randomized to the Control Group (CG=104) and Intervention Group (IG=260). INTERVENTION: Supervised walking program of 120min/week with sociocultural activities once a month. MAIN MEASUREMENTS: At baseline and at post-intervention we assessed: PA (IPAQ-S), self-esteem (Rosenberg scale) and cardiovascular indicators: smoking, systolic (SBP) and diastolic (DBP) blood pressure, serum LDL and HDL cholesterol, and serum glucose. Sociodemographic characteristics and diagnostic of chronic diseases are recorded. RESULTS: The Program increased the PA in the IG (P=.001), while it decreased in the CG (P=.002), and also the self-esteem in the group of participants (1.28 points, P=.006) and in the groups with diagnoses of hypertension (1.60 points, P=.005), dyslipidemia (1.62 points, P=.012), excess weight (1.24 points, P=.011) or anxiety/depression (1.53 points, P=.045), assessed by multivariate statistical models. The increase in self-esteem during the intervention decreased SBP -0.5mmHg (P=.030) in the hypertension group, regardless of baseline SBP and the effect of the intervention. CONCLUSION: The PA program increased the PA and self-esteem in adult primary care users. The increase of self-esteem improved the control of SBP in hypertensive patients.


Assuntos
Doença Crônica/psicologia , Avaliação de Programas e Projetos de Saúde , Autoimagem , Participação Social/psicologia , Caminhada/psicologia , Idoso , Ansiedade/psicologia , Pressão Sanguínea , Depressão , Dislipidemias/psicologia , Exercício Físico/psicologia , Feminino , Humanos , Hipertensão/psicologia , Masculino , Pessoa de Meia-Idade , Sobrepeso/psicologia , Atenção Primária à Saúde , Classe Social , Fatores de Tempo
10.
Glob Chang Biol ; 24(7): 2749-2751, 2018 07.
Artigo em Inglês | MEDLINE | ID: mdl-29668107

RESUMO

Climatic stressors due to global change induce important modifications to the chemical composition of plant cuticles and their biophysical properties. In particular, plant cuticles can become heavier, stiffer and more inert, improving plant protection.


Assuntos
Adaptação Fisiológica , Mudança Climática , Epiderme Vegetal/fisiologia , Plantas , Temperatura , Água , Ceras
11.
Plant Physiol ; 170(2): 935-46, 2016 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-26668335

RESUMO

The epidermis plays a pivotal role in plant development and interaction with the environment. However, it is still poorly understood, especially its outer epidermal wall: a singular wall covered by a cuticle. Changes in the cuticle and cell wall structures are important to fully understand their functions. In this work, an ultrastructure and immunocytochemical approach was taken to identify changes in the cuticle and the main components of the epidermal cell wall during tomato fruit development. A thin and uniform procuticle was already present before fruit set. During cell division, the inner side of the procuticle showed a globular structure with vesicle-like particles in the cell wall close to the cuticle. Transition between cell division and elongation was accompanied by a dramatic increase in cuticle thickness, which represented more than half of the outer epidermal wall, and the lamellate arrangement of the non-cutinized cell wall. Changes in this non-cutinized outer wall during development showed specific features not shared with other cell walls. The coordinated nature of the changes observed in the cuticle and the epidermal cell wall indicate a deep interaction between these two supramolecular structures. Hence, the cuticle should be interpreted within the context of the outer epidermal wall.


Assuntos
Parede Celular/ultraestrutura , Frutas/crescimento & desenvolvimento , Frutas/ultraestrutura , Epiderme Vegetal/ultraestrutura , Solanum lycopersicum/crescimento & desenvolvimento , Solanum lycopersicum/ultraestrutura , Contagem de Células , Divisão Celular , Proliferação de Células , Celulose/metabolismo , Frutas/citologia , Solanum lycopersicum/citologia , Pectinas/metabolismo , Epiderme Vegetal/anatomia & histologia , Epiderme Vegetal/citologia , Epiderme Vegetal/crescimento & desenvolvimento
12.
J Exp Bot ; 68(19): 5389-5400, 2017 Nov 09.
Artigo em Inglês | MEDLINE | ID: mdl-29040673

RESUMO

The assembly of the lipophilic cuticle layer and suberin lamellae, approximately 450 million years ago, was a major evolutionary development that enabled plants to colonize terrestrial habitats. The cuticle layer is composed of cutin polyester and embedded cuticular waxes, whereas the suberin lamellae consist of very long chain fatty acid derivatives, glycerol, and phenolics cross-linked with alkyl ferulate-embedded waxes. Due to their substantial biological roles in plant life, the mechanisms underlying the assembly of these structures have been extensively investigated. In the last decade, the introduction of 'omics' approaches, including genomics, transcriptomics, proteomics, and metabolomics, have been key in the identification of novel genetic and chemical elements involved in the formation and function of the cuticle layer and suberin lamellae. This review summarizes contemporary studies that utilized various large-scale, 'omics' strategies in combination with novel technologies to unravel how building blocks and polymers of these lipophilic barriers are made, and moreover linking structure to function along developmental programs and stress responses. We anticipate that the studies discussed here will inspire scientists studying lipophilic barriers to integrate complementary 'omics' approaches in their efforts to tackle as yet unresolved questions and engage the main challenges of the field to date.


Assuntos
Perfilação da Expressão Gênica/métodos , Genômica/métodos , Metabolômica/métodos , Epiderme Vegetal/fisiologia , Fenômenos Fisiológicos Vegetais/genética , Proteômica/métodos , Perfilação da Expressão Gênica/instrumentação , Genômica/instrumentação , Metabolômica/instrumentação , Epiderme Vegetal/genética , Proteômica/instrumentação , Ceras/metabolismo
13.
J Exp Bot ; 68(19): 5401-5410, 2017 Nov 09.
Artigo em Inglês | MEDLINE | ID: mdl-28992177

RESUMO

Cutin is the main component of plant cuticles constituting the framework that supports the rest of the cuticle components. This biopolymer is composed of esterified bi- and trifunctional fatty acids. Despite its ubiquity in terrestrial plants, it has been underutilized as raw material due to its insolubility and lack of melting point. However, in recent years, a few technologies have been developed to obtain cutin monomers from several agro-wastes at an industrial scale. This review is focused on the description of cutin properties, biodegradability, chemical composition, processability, abundance, and the state of art of the fabrication of cutin-based materials in order to evaluate whether this biopolymer can be considered a source for the production of renewable materials.


Assuntos
Agricultura , Conservação dos Recursos Naturais/métodos , Lipídeos de Membrana/análise , Plásticos/análise , Resíduos Sólidos/análise , Indústria de Processamento de Alimentos , Eliminação de Resíduos/métodos
14.
Physiol Plant ; 161(4): 560-567, 2017 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-28767133

RESUMO

Cutinsomes, spherical nanoparticles containing cutin mono- and oligomers, are engaged in cuticle formation. Earlier they were revealed to participate in cuticle biosynthesis in Solanum lycopersicum fruit and Ornithogalum umbellatum ovary epidermis. Here, transmission electron microscopy (TEM) and immunogold labeling with antibody against the cutinsomes were applied to aerial cotyledon epidermal cells of Arabidopsis thaliana mature embryos. TEM as well as gold particles conjugated with the cutinsome antibody revealed these structures in the cytoplasm, near the plasmalemma, in the cell wall and incorporated into the cuticle. Thus, the cutinsomes most probably are involved in the formation of A. thaliana embryo cuticle and this model plant is another species in which these specific structures participate in the building of cuticle in spite of the lack of the lipotubuloid metabolon. In addition, a mechanism of plant cuticle lipid biosynthesis based on current knowledge is proposed.


Assuntos
Arabidopsis/metabolismo , Arabidopsis/genética , Cotilédone/genética , Cotilédone/metabolismo , Regulação da Expressão Gênica de Plantas/genética , Regulação da Expressão Gênica de Plantas/fisiologia , Microscopia Eletrônica de Transmissão , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Sementes/genética , Sementes/metabolismo
15.
Plant Physiol ; 168(3): 1036-48, 2015 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-26019301

RESUMO

Fruit development and ripening entail key biological and agronomic events, which ensure the appropriate formation and dispersal of seeds and determine productivity and yield quality traits. The MADS box gene Arlequin/tomato Agamous-like1 (hereafter referred to as TAGL1) was reported as a key regulator of tomato (Solanum lycopersicum) reproductive development, mainly involved in flower development, early fruit development, and ripening. It is shown here that silencing of the TAGL1 gene (RNA interference lines) promotes significant changes affecting cuticle development, mainly a reduction of thickness and stiffness, as well as a significant decrease in the content of cuticle components (cutin, waxes, polysaccharides, and phenolic compounds). Accordingly, overexpression of TAGL1 significantly increased the amount of cuticle and most of its components while rendering a mechanically weak cuticle. Expression of the genes involved in cuticle biosynthesis agreed with the biochemical and biomechanical features of cuticles isolated from transgenic fruits; it also indicated that TAGL1 participates in the transcriptional control of cuticle development mediating the biosynthesis of cuticle components. Furthermore, cell morphology and the arrangement of epidermal cell layers, on whose activity cuticle formation depends, were altered when TAGL1 was either silenced or constitutively expressed, indicating that this transcription factor regulates cuticle development, probably through the biosynthetic activity of epidermal cells. Our results also support cuticle development as an integrated event in the fruit expansion and ripening processes that characterize fleshy-fruited species such as tomato.


Assuntos
Frutas/genética , Genes de Plantas , Proteínas de Domínio MADS/genética , Epiderme Vegetal/crescimento & desenvolvimento , Solanum lycopersicum/crescimento & desenvolvimento , Solanum lycopersicum/genética , Transcrição Gênica , Fenômenos Biomecânicos , Vias Biossintéticas/genética , Flores/anatomia & histologia , Flores/fisiologia , Frutas/citologia , Frutas/crescimento & desenvolvimento , Regulação da Expressão Gênica no Desenvolvimento , Regulação da Expressão Gênica de Plantas , Proteínas de Domínio MADS/metabolismo , Fenótipo , Epiderme Vegetal/genética , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Interferência de RNA , RNA Mensageiro/genética , RNA Mensageiro/metabolismo
16.
Plant Physiol ; 166(3): 1371-86, 2014 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-25277718

RESUMO

Tomato (Solanum lycopersicum) fruit ripening is accompanied by an increase in CHALCONE SYNTHASE (CHS) activity and flavonoid biosynthesis. Flavonoids accumulate in the cuticle, giving its characteristic orange color that contributes to the eventual red color of the ripe fruit. Using virus-induced gene silencing in fruits, we have down-regulated the expression of SlCHS during ripening and compared the cuticles derived from silenced and nonsilenced regions. Silenced regions showed a pink color due to the lack of flavonoids incorporated to the cuticle. This change in color was accompanied by several other changes in the cuticle and epidermis. The epidermal cells displayed a decreased tangential cell width; a decrease in the amount of cuticle and its main components, cutin and polysaccharides, was also observed. Flavonoids dramatically altered the cuticle biomechanical properties by stiffening the elastic and viscoelastic phase and by reducing the ability of the cuticle to deform. There seemed to be a negative relation between SlCHS expression and wax accumulation during ripening that could be related to the decreased cuticle permeability to water observed in the regions silencing SlCHS. A reduction in the overall number of ester linkages present in the cutin matrix was also dependent on the presence of flavonoids.


Assuntos
Aciltransferases/genética , Epiderme Vegetal/citologia , Solanum lycopersicum/fisiologia , Aciltransferases/metabolismo , Flavonoides/metabolismo , Frutas/citologia , Frutas/fisiologia , Regulação da Expressão Gênica de Plantas , Inativação Gênica , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Espectroscopia de Infravermelho com Transformada de Fourier , Ceras/química
17.
New Phytol ; 202(3): 790-802, 2014 May.
Artigo em Inglês | MEDLINE | ID: mdl-24571168

RESUMO

In this study, growth-dependent changes in the mechanical properties of the tomato (Solanum lycopersicum) cuticle during fruit development were investigated in two cultivars with different patterns of cuticle growth and accumulation. The mechanical properties were determined in uniaxial tensile tests using strips of isolated cuticles. Changes in the functional groups of the cuticle chemical components were analysed by attenuated total reflectance-Fourier transform infrared (ATR-FTIR). The early stages of fruit growth are characterized by an elastic cuticle, and viscoelastic behaviour only appeared at the beginning of cell enlargement. Changes in the cutin:polysaccharide ratio during development affected the strength required to achieve viscoelastic deformation. The increase in stiffness and decrease in extensibility during ripening, related to flavonoid accumulation, were accompanied by an increase in cutin depolymerization as a result of a reduction in the overall number of ester bonds. Quantitative changes in cuticle components influence the elastic/viscoelastic behaviour of the cuticle. The cutin:polysaccharide ratio modulates the stress required to permanently deform the cuticle and allow cell enlargement. Flavonoids stiffen the elastic phase and reduce permanent viscoelastic deformation. Ripening is accompanied by a chemical cleavage of cutin ester bonds. An infrared (IR) band related to phenolic accumulation can be used to monitor changes in the cutin esterification index.


Assuntos
Frutas/crescimento & desenvolvimento , Frutas/fisiologia , Epiderme Vegetal/crescimento & desenvolvimento , Epiderme Vegetal/fisiologia , Solanum lycopersicum/fisiologia , Fenômenos Biomecânicos , Elasticidade , Esterificação , Genótipo , Solanum lycopersicum/genética , Lipídeos de Membrana/metabolismo , Fenóis/metabolismo , Espectroscopia de Infravermelho com Transformada de Fourier , Viscosidade
18.
Front Plant Sci ; 15: 1343452, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38434425

RESUMO

Fruit cracking, a widespread physiological disorder affecting various fruit crops and vegetables, has profound implications for fruit quality and marketability. This mini review delves into the multifaceted factors contributing to fruit cracking and emphasizes the pivotal roles of environmental and agronomic factors in its occurrence. Environmental variables such as temperature, relative humidity, and light exposure are explored as determinants factors influencing fruit cracking susceptibility. Furthermore, the significance of mineral nutrition and plant growth regulators in mitigating fruit cracking risk is elucidated, being calcium deficiency identified as a prominent variable in various fruit species. In recent years, precision farming and monitoring systems have emerged as valuable tools for managing environmental factors and optimizing fruit production. By meticulously tracking parameters such as temperature, humidity, soil moisture, and fruit skin temperature, growers can make informed decisions to prevent or alleviate fruit cracking. In conclusion, effective prevention of fruit cracking necessitates a comprehensive approach that encompasses both environmental and agronomic factors.

19.
Polymers (Basel) ; 16(6)2024 Mar 14.
Artigo em Inglês | MEDLINE | ID: mdl-38543419

RESUMO

Biodegradable mulching films are a very attractive solution to agronomical practices intended to achieve more successful crop results. And, in this context, the employment of agricultural and industrial food residues as starting material for their production is an alternative with economic and environmental advantages. This work reports the preparation of bilayer films having two different wettability characteristics from three bio-derived biopolymers: TEMPO-oxidized cellulose nanofibers isolated from infused Yerba Mate residues, Chitosan and Polylactic acid. The infused Yerba Mate residues, the isolated and oxidized cellulose nanofibers, and the films were characterized. Nanofibrillation yield, optical transmittance, cationic demand, carboxyl content, intrinsic viscosity, degree of polymerization, specific surface area and length were studied for the (ligno)cellulose nanofibers. Textural and chemical analysis, thermal and mechanical properties studies, as well as water and light interactions were included in the characterization of the films. The bilayer films are promising materials to be used as mulching films.

20.
Sci Adv ; 9(39): eadi3055, 2023 Sep 29.
Artigo em Inglês | MEDLINE | ID: mdl-37756397

RESUMO

Plant material culture can offer unique insights into the ways of life of prehistoric societies; however, its perishable nature has prevented a thorough understanding of its diverse and complex uses. Sites with exceptional preservation of organic materials provide a unique opportunity for further research. The burial site of Cueva de los Murciélagos in southern Iberia, uncovered during 19th-century mining activities, contained the best-preserved hunter-gatherer basketry in southern Europe, together with other unique organic artifacts associated with the first farming communities, such as sandals and a wooden hammer. We present 14 14C dates for the perishable artifacts (N = 76), situating the assemblage between the Early and Middle Holocene (c. 7500 to 4200 cal BCE). Our integrated analysis includes raw material determination and technological and chrono-cultural contextualization of this unique and important set of materials.

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