Purification of archetypal soybean root suberin mostly comprising alka(e)noic acids using an ionic liquid catalyst

Soybean (Glycine max) is an increasingly relevant crop due to its economic importance and also a model plant for the study of root symbiotic associations with nodule forming rhizobia. Plant polyesters mediate plant-microbe interactions with both pathogenic and beneficial microbes; suberin has been hypothesized to play a key role during the early steps of rhizobia attachment to the root. The downside is that suberin chemistry in soybean root is still scarcely studied. This study addresses this outstanding question by reporting a straightforward workflow for a speedy purification of suberin from soybean root and for its subsequent detailed chemical analysis. To purify suberin, cholinium hexanoate (an ionic liquid) was used as the catalyst. The ensuing suberin is highly esterified as observed by a precise Nuclear Magnetic Resonance quantification of each ester type, discriminating between primary and acylglycerol esters. Moreover, the composing hydrolysable monomers detected through GC-MS revealed that hexadecanoic acid is the most abundant monomer, similar to that reported before by others. Overall, this study highlights the adequacy of the ionic liquid catalyst for the isolation of suberin from soybean roots, where the polymer natural abundance is low, and builds new knowledge on the specificities of its chemistry; essential to better understand the biological roles of suberin in roots

Cutin-Derived Oligomers Act as Damage-Associated Molecular Patterns in Arabidopsis thaliana

The cuticle constitutes the outermost defensive barrier of most land plants. It comprises a polymeric matrix – cutin, surrounded by soluble waxes. Moreover, the cuticle constitutes the first line of defense against pathogen invasion, while also protecting the plant from many abiotic stresses. Aliphatic monomers in cutin have been suggested to act as immune elicitors in plants. This study analyses the potential of tomato cutin oligomers to act as damage-associated molecular patterns (DAMPs) able to induce a rapid immune response in the model plantArabidopsis. Cutin oligomeric mixtures led to Ca 2+ influx and MAPK activation inArabidopsis. Comparable responses were measured for cutin, which was also able to induce a reactive oxygen species (ROS) burst. Furthermore, treatment ofArabidopsiswith cutin oligomers resulted in a unique transcriptional reprogramming profile, having many archetypal features of pattern-triggered immunity (PTI). Targeted spectroscopic and spectrometric analyses of the cutin oligomers suggest that the elicitors compounds consist mostly of two up to three 10,16-dihydroxyhexadecanoic acid monomers linked together through ester bonds. This study demonstrates that cutin breakdown products can act as DAMPs; a novel class of elicitors deserving further characterization

Novel ionic liquids-based extraction method that preserves molecular structure from cutin

Abstract The biopolyester cutin is ubiquitous in land plants, building the polymeric matrix of the plant’s outermost defensive barrier - the cuticle. Cutin influences many biological processes in planta however due to its complexity and highly branched nature, the native structure remains partially unresolved. Our aim was to define an original workflow for the purification and systematic characterisation of the molecular structure of cutin. To purify cutin we tested the ionic liquids cholinium hexanoate and 1-butyl-3-methyl-imidazolium acetate. The ensuing polymers are highly esterified, amorphous and have the typical monomeric composition as demonstrated by solid state NMR, complemented by spectroscopic (GC-MS), thermal (DSC) and x-ray scattering (WAXS) analyses. A systematic study by solution-state NMR of cryogenically milled cutins extracted from Micro-Tom tomatoes (the wild type and the gpat6 and cus1 mutants) was undertaken. Their molecular structures, relative distribution of ester aliphatics, free acid end-groups and free hydroxyl groups, differentiating between those derived from primary and secondary esters, were solved. The acquired data demonstrate the existence of free hydroxyl groups in cutin and reveal novel insights on how the mutations impact the esterification arrangement of cutin. Compared to conventional approaches, the usage of ionic liquids for the study of plant polyesters opens new avenues since simple modifications can be applied to recover a biopolymer carrying distinct types/degrees of modifications ( e.g . preservation of esters or cuticular polysaccharides), which in combination with the solution NMR methodologies developed here, constitutes now essential tools to fingerprint the multi-functionality and the structure of cutin in planta

Cutin-Derived Oligomers Induce Hallmark Plant Immune Responses

The cuticle constitutes the outermost defensive barrier of most land plants. It comprises a polymeric matrix – cutin, surrounded by soluble waxes. Moreover, the cuticle constitutes the first line of defense against pathogen invasion, while also protecting the plant from many abiotic stresses. Aliphatic monomers in cutin have been suggested to act as immune elicitors in plants. This study analyses the potential of cutin oligomers to activate rapid signaling outputs reminiscent of pattern-triggered immunity (PTI) in the model plant Arabidopsis. Cutin oligomeric mixtures led to Ca2+ influx and MAPK activation. Comparable responses were measured for cutin, which was also able to induce a reactive oxygen species (ROS) burst. Furthermore, cutin oligomer treatment resulted in a unique transcriptional reprogramming profile, having many archetypal features of PTI. Targeted spectroscopic and spectrometric analyses of the cutin oligomers suggest that the elicitors compounds consist mostly of two up to three 10,16-dihydroxyhexadecanoic acid monomers linked together through ester bonds. This study demonstrates that cutin breakdown products can act as inducers of early plant immune responses, which underlying mechanisms of perception and potential use in agriculture warrant further investigation

Bioinspired co-polyesters of hydroxy-fatty acids extracted from tomato peel agro-wastes and glycerol with tunable mechanical, thermal and barrier properties

International audienceBy mimicking the cutin natural polyester networks of plant cuticles, we produced hydrophobic elastomers by a sustainable process, i.e., using a catalyst- and solvent-free polycondensation of glycerol and hydroxy fatty acids, two by-products of the agro-food industry. The hydroxy fatty acid fraction was obtained by ethanolic alkaline hydrolysis of cuticle from industrial tomato. This industrial-like fatty acid fraction contained more than 90 wt%. of 9(10),16 dihydroxyhexadecanoic acid (diOHC16). The co-polyesters were designed by increasing the ratio of esterified glycerol/diOHC16 in a range observed in plant cutins (up to 6 wt%). Their structure and functional properties (thermal, mechanical, gas permeability, interaction with bacterial cells) were characterized. Increasing the glycerol contents induced a significant decrease in the crosslink density of the polyesters and the formation of crystalline domains with a hexagonal organization. These structural modifications were related to a marked increase of elastomeric extensibility (up to 217 %). While water vapor permeability was not impacted, the increase of glycerol content induced a significant decrease in oxygen permeability. None of the polyesters displayed biocide activity, but an increase of glycerol content significantly reduced the adhesion of bacterial cells, potentially giving rise to antifouling applications

ANÁLISE SITUACIONAL DO RASTREAMENTO MAMOGRÁFICO DO CÂNCER DE MAMA NO PIAUÍ

Câncer de mama, o mais incidente no mundo depois do câncer de pulmão, é o que mais atinge as mulheres em todo o planeta. O presente trabalho propôs investigar como também avaliar a adequação às diretrizes nacionais e a qualidade do rastreamento mamográfico no estado do Piauí. Trata-se de um estudo descritivo realizado a partir dos dados secundários do Sistema de Informação do Câncer e do Sistema de Informação Ambulatorial do Sistema Único de Saúde, de 2016 a 2019. O Piauí foi o estado do Nordeste que mais amplificou a produção de mamografias chegando a um aumento percentual de 4.146,11%. Houve predomínio de mamografias de rastreamento em mulheres de 50 a 69 anos, público-alvo do rastreio do câncer de mama. O número de exames realizados anualmente ultrapassou a periodicidade bienal. As mamografias de rastreamento com realização em até 30 dias superaram as mamografias diagnósticas em todo o período do estudo. Os exames com resultado em até 30 dias apresentaram percentuais maiores para mamografias diagnósticas nos anos de 2016 e 2017 que para os exames de rastreamento, com uma queda considerável nos anos seguintes. As mamografias de rastreamento apresentaram BI-RADS 1 e 2 e nos resultados de BI-RADS inconclusivos, os percentuais foram mais expressivos. A razão entre biópsias e mamografias com resultados BI-RADS 4 e 5 oscilou entre 0,01 e 1,0. Nosso estudo constatou que o Piauí, nesse intervalo de tempo, conseguiu melhorar o acesso à mamografia, entretanto, houve baixa cobertura associada à inadequação das diretrizes técnicas nacionais do rastreamento mamográfic