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Rhamnogalacturonan II (RG-II) is a structurally complex and conserved domain of the pectin present in the primary cell walls of vascular plants. Borate cross-linking of RG-II is required for plants to grow and develop normally. Mutations that alter RG-II structure also affect cross-linking and are lethal or severely impair growth. Thus, few genes involved in RG-II synthesis have been identified. Here, we developed a method to generate viable loss-of-function Arabidopsis (Arabidopsis thaliana) mutants in callus tissue via CRISPR/Cas9-mediated gene editing. We combined this with a candidate gene approach to characterize the male gametophyte defective 2 (MGP2) gene that encodes a putative family GT29 glycosyltransferase. Plants homozygous for this mutation do not survive. We showed that in the callus mutant cell walls, RG-II does not cross-link normally because it lacks 3-deoxy-D-manno-octulosonic acid (Kdo) and thus cannot form the α-L-Rhap-(1→5)-α-D-kdop-(1→sidechain). We suggest that MGP2 encodes an inverting RG-II CMP-β-Kdo transferase (RCKT1). Our discovery provides further insight into the role of sidechains in RG-II dimerization. Our method also provides a viable strategy for further identifying proteins involved in the biosynthesis of RG-II.

Copyright of Shipin Kexue/ Food Science is the property of Food Science Editorial Department and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Abstract\nNOVELTY STATEMENTSAluminum (Al) is a trace element that may hamper plant growth and development. Tolerance mechanisms could imply the cell wall as it is the first barrier before entry into the plant cell. Douglas-fir plantlets were grown in vitro on media supplemented with different aluminum chloride (AlCl3) concentrations up to 1 mM. The characterization of the cell wall revealed quantitative and qualitative modifications in the polysaccharidic composition of the wall, in particular in roots whose pectins showed a higher galacturonic acid content with less ramification and a lower degree of methylesterification (DME) explained by a higher pectin methylesterase activity; these Al-induced changes suggest an Al-trapping process in cell wall structures. In stems and needles, the observed increase in DME rather suggests an exclusion of Al from the cell wall.Douglas-fir is a coniferous species that has shown tolerance against trace elements such as aluminum. In this study, changes in cell wall polysaccharides were observed in plants grown in the presence of Al, notably in roots. The contents and the structures of pectins were affected, leading to a trapping process in roots due to an abundance of low methylesterified pectins, and an exclusion process from the cell wall in stem and needles with less Al-binding sites in pectins. [ABSTRACT FROM AUTHOR]

As one of the most influential environmental factors, light fundamentally shapes plant physiology and growth traits. 1,2,3,4,5,6,7,8,9,10 The hypocotyl is critical for the morphological establishment of the seedling, and its length displays remarkable plasticity upon perception of changes in the light conditions. 4,5,8,9,10,11,12,13,14,15 Although remodeling of the primary cell walls is well-documented to play an important role in hypocotyl growth, how the hypocotyl elongation rate is swiftly repressed at the dark-to-light transition remains elusive. 16,17,18,19,20,21,22,23,24,25 Here, we show that expression of an Arabidopsis microRNA, miR775, is quickly inhibited at the dark-to-light transition by ELONGATED HYPOCOTYL 5 (HY5), an essential negative regulator of hypocotyl elongation that is degraded in the dark and accumulates in the light. 26 We found that this repression allows the miR775-targeted GALACTOSYLTRANSFERASE 9 (GALT9) to accumulate in the transverse walls of hypocotyl cells within 10 min of light exposure. Genetic analysis coupled with time-lapse photography demonstrates that GALT9 is both necessary and sufficient for controlling the differential hypocotyl growth rates at the dark-to-light transition. Immunohistochemical analysis and coherent Raman microscopy reveal that the polarized accumulation of GALT9 confers a rapid increase in the pectin content of the transverse walls. Atomic force microscopy (AFM) confirms that polarized pectin accumulation mediated by the HY5-miR775-GALT9 repression cascade correlates with rapid asymmetric increases in cell wall rigidity and hence decreases in cell elongation in the light. Together, these findings add new insights into the cellular mechanism governing differential hypocotyl growth at the dark-to-light transition and should also benefit the general understanding of polarized cell expansion in plants. [Display omitted] • Triggered by light, GALT9 accumulates in the transverse walls of hypocotyl cells • GALT9 polarization confers a rapid increase in pectin level and mechanical stiffness • Such polarization slows down longitudinal growth of the hypocotyl Hypocotyl elongation is rapidly repressed when dark-grown plants are exposed to light. Zhang et al. show that the HY5-miR775-GALT9 pathway allows preferential GALT9 accumulation in the transverse walls at the dark-to-light transition, which increases pectin level and mechanical stiffness of the transverse walls to inhibit longitudinal growth. [ABSTRACT FROM AUTHOR]

In this work, an innovative three-layer sensor was developed in a fully sustainable design. For that purpose, pectin and anthocyanins from Morus nigra and Prosopis alba were used. Furthermore, mixtures of beeswax and colophony as hydrophobic layers were used to prevent the moisture from affecting the sensor work. The ratio of beeswax/colophony (B/C) was studied to optimize the moisture barrier. The response of colorimetric sensors pectin-Morus nigra (PMN) and pectin-Prosopis alba (PPA) in vapors of simulant solutions was recorded. Furthermore, physicochemical and microbiological tests on fresh bovine meat were carried out, and volatile compound content (VC) was correlated with color changes in PMN and PPA sensors. The results depicted that the optimal ratio in the waterproof layer was B/C: 70/30 (BC3) showing the highest water contact angle of 112° and minimal water vapor absorption value of 2.4%. In addition, the light transmittance of the BC3 layer allows to perceive the color of the sensor without alteration. The outcomes of the simulation test showed differences in color values of 26 and 31 to PMN and PPA, respectively, highlighting the ability of both sensors to allow the detection of quality changes in packaged bovine meat. This research paves the way for the development of sustainable and environmentally friendly colorimetric sensors with diverse applications. [ABSTRACT FROM AUTHOR]

The aim of this study was to optimize sequential ultrasound-radio frequency–assisted extraction (URAE) of pectin from pomelo peel. Effects of sonication power and time, radio frequency (RF) heating temperature, and time on the pectin yield (PY) were evaluated. Based upon optimized URAE parameters, the yield, physicochemical, and structure properties of pectin recovered from sequential radio frequency-ultrasound–assisted extraction (RUAE), ultrasound-assisted extraction (UAE), and RF-assisted extraction (RFAE) were also compared. A maximal PY of 28.36 ± 0.85% was attained at the optimized URAE conditions including solvent pH of 1.5 (citric acid), sonication at 183 W for 24 min, and RF heating at 87 °C for 23 min. Although all four samples had a high degree of esterification more than 50%, URAE was the lowest. No significant changes were observed in the types of monosaccharides among different samples. Furthermore, all four samples (6.6–10.3 mg GAE/g) showed significantly higher total phenolic content than those of commercial citrus pectin (1.2 mg GAE/g), and among them, RFAE was the highest with the best antioxidant capacity. The water and oil holding capacities of the four samples were between 3.5 to 4.0 and 2.6 to 3.0 g/g, respectively, but there was no significant difference (p > 0.05) between each other. Structure properties indicated that there were no significant differences in the main chemical structures among the four pectin samples. Morphology analysis of URAE showed a more compact, smoother, and flatter surface than that of RUAE and RFAE. The results observed in this paper suggest that sequential URAE is an efficient strategy for the recovery of high-quality pectins. [ABSTRACT FROM AUTHOR]

Cadmium (Cd) contamination in agricultural soil brings severe health risks through the dietary intake of Cd‐polluted crops. The comprehensive role of pectin in lowering Cd accumulation is investigated through low Cd accumulated (L) and high Cd accumulated (H) cultivars of L. sativa. The significantly different Cd contents in the edible parts of two L. sativa cultivars are accomplished by different Cd transportations. The pectin is the dominant responsive cell wall component according to significantly increased uronic acid contents and the differential Cd absorption between unmodified and modified cell wall. The chemical structure characterization revealed the decreased methyl esterification in pectin under Cd treatment compared with control. Significantly brighter LM19 relative fluorescence density and 40.82% decreased methanol in the root pectin of L cultivar under Cd treatment (p < 0.05) supported that the de‐methyl esterification of root pectin is more significant in L cultivar than in H cultivar. The pectin de‐methyl esterification of L cultivar is achieved by the upregulation of pectin esterases and the downregulation of pectin esterase inhibitors under Cd treatments, which has facilitated the higher Cd‐binding of pectin. Our findings provide deep insight into the differential Cd accumulation of L. sativa cultivars and contribute to the understanding the pollutant behaviors in plants. Summary statement: Cd‐pollution safe cultivar (Cd‐PSC) with low Cd accumulation in edible parts is a promising strategy to minimize the Cd pollution risk of crops and guarantee food security even in Cd pollution soil. Our study has illustrated the role of root pectin de‐methyl esterification in determining the Cd accumulation in L. Sativa through comprehensive physiological, chemical characterization, and molecular methods, supporting de‐methyl esterification of pectin in L cultivar plays a more prominent role in root pectin detaining Cd. We believe that our study makes a significant contribution to understanding different Cd accumulation mechanisms and molecular‐assistant Cd‐PSC breeding of Lactuca Sativa. [ABSTRACT FROM AUTHOR]

Heavy metal pollution is a worldwide problem that threaten agricultural production and human health. Methyl jasmonate (MeJA) is a phytohormone that could enhance plant resistance against various stresses. However, the mechanism of MeJA in cadmium (Cd) uptake, distribution, and translocation in rice plants remains elusive. In this study, we found that the Cd induced-growth inhibition was ameliorated by MeJA. Upon MeJA application, Cd content in root and shoot was decreased by 10.15 % and 36.39 %, which paralleled with less Cd2 + influx of rice roots and depressed expression of the cation transporters (OsNramp1 and OsNramp5). The subcellular distribution revealed that MeJA enriched Cd distribution in cell wall, which was accompanied by increased cell wall thickness and altered cell wall polysaccharide (pectin, cellulose, hemicellulose) content, meanwhile, the Cd content in pectin, cellulose, hemicellulose was increased, the FTIR analysis implied that functional groups (especially -OH and COO-) on cell wall were involved in Cd fixation. The root to shoot translocation of Cd was hindered by exogenous MeJA, this was validated by the decreased expression of OsHMA2 in root and declined Cd level in xylem sap. Overall, our results revealed that MeJA could act as a foliar resistance control substance to reduce Cd accumulation in rice plants. The detailed molecular mechanisms of MeJA in Cd detoxification in plants still need further investigation. • The Cd-induced growth inhibition of rice seedlings was alleviated by MeJA. • The root, shoot and overall Cd accumulation in rice seedlings were limited by MeJA. • The MeJA reduced net Cd2+ influx by depressing OsNRamp1 and OsNRamp5 expression. • The MeJA inhibited Cd translocation from root to shoot and Cd content in xylem. • The MeJA reconstructed cell wall components and improved its Cd fixation capability. [ABSTRACT FROM AUTHOR]

Key message: Carrot callus grown on a medium with increased nitrogen have reduced carotenoid accumulation, changed gene expression, high amount of vesicular plastids and altered cell wall composition. Carotenoid biosynthesis is vital for plant development and quality, yet its regulation under varying nutrient conditions remains unclear. To explore the effects of nitrogen (N) availability, we used carrot (Daucus carota L.) model callus cultures in vitro as a controlled system for studying nutrient-regulated metabolic processes. Two mineral media differing in N content and NO₃⁻/NH₄⁺ ratios were used. Comprehensive analyses, HPLC, transmission electron microscopy, immunochemistry, and RNA sequencing, revealed notable cellular and molecular responses to N treatments. The results demonstrated that N supplementation reduced carotenoid content by 50%, particularly β-carotene and α-carotene. The composition of chromoplast types shifted, with vesicular chromoplasts dominating (55%), followed by a globular type (23%), while in the control callus, globular and crystalline types predominated (57% and 33%, respectively). Immunohistochemistry showed increased presence of high-esterified pectins and arabinogalactan proteins in N-treated cells. Transcriptomic analysis identified 1704 differentially expressed genes (DEGs), including only two in the carotenoid biosynthesis pathway: phytoene synthase 2 (PSY2) and zeaxanthin epoxidase (ZEP). PSY2, which encodes the carotenoid rate-limiting enzyme, showed expression levels that corresponded with reduced carotene content. Other DEGs included 15 involved in nitrogen transport, 1 in nitrogen assimilation, 40 in cell wall biosynthesis and modification, and 9 in phenylpropanoid/flavonoid pathways. N-treated callus exhibited altered expression of MADS-box, NLP, bZIP, and ethylene-responsive transcription factors. These findings reveal how nitrogen availability disrupts carotenoid biosynthesis and triggers extensive chromoplast and cell wall remodeling, providing a cellular framework for understanding nutrient-regulated metabolic shifts. [ABSTRACT FROM AUTHOR]

With rising concerns about antibiotic resistance globally, exploring innovative antibacterial strategies is vital for public health. This work aimed innovatively to improve the biological efficacy of pectin (Pec) hydrogel beads by synergistically utilizing an antibacterial zeolitic imidazolate metal-organic framework (ZIF-8) and tetracycline (TC). ZIF-8 was incorporated at various concentrations within the hydrogel matrix to end this using an in-situ synthesis technique. TC was also pre-loaded into Pec hydrogel beads to further improve their antibacterial features. The application of diverse analysis techniques validated the successful fabrication of nanocomposites. In-vitro Zn2+ and TC release were considered by simulating the human digestive system, indicating a sustained and controlled release rate during 8 h (pH 1.2:6.8:7.4 = 20%:20%:60%). Antibacterial tests displayed inhibition zones of 14 ± 0.5 mm and 12 ± 0.5 mm against Escherichia coli and Staphylococcus aureus bacteria. Additionally, the MTT assay displayed potent cytotoxicity (> 70% cell viability after 48 h) for the human colon adenocarcinoma HT29 cell line. These results suggest that the developed nanocomposites have promising potential as an antibacterial bio-platform that is effective against resistant pathogens commonly found in the gastrointestinal tract. [ABSTRACT FROM AUTHOR]

Burkholderia cenocepacia causes life-threatening infections in immunocompromised patients. Treatment is challenging due to intrinsic antibiotic multiresistance, so vaccination provides an alternative approach. We aimed to identify vaccine candidates using reverse vaccinology and evaluate their efficacy as protein-loaded chitosan: pectin nanoparticles (C:P NPs) in a vaccine model. Applying strict subtractive channels, three proteins were shortlisted: WP_006481710.1 (LY), WP_012493605.1 (KT), and WP_006492970.1 (BD). Proteins were cloned, purified as His-tagged proteins, and loaded onto C:P NPs. Vaccinated mice had significantly higher systemic IgG and mucosal IgA antibody responses and induced IL-6 and IL-17A. 6x-His-LY-CS:P NPs and 6x-His-KT-CS:P NPs vaccines induced TNF-α. Vaccines conferred significant protection against B. cenocepacia intranasal infections. In conclusion, cyclic-di-AMP phosphodiesterase (WP_012493605.1) is a promising vaccine candidate that elicited IgG and IgA antibodies, Th1, Th2, and Th17 cellular immunity in BALB/c mice and protected against B. cenocepacia infection. This provides hope for saving lives of people at high risk of infection. [ABSTRACT FROM AUTHOR]

The extraction of health-promoting compounds from waste biomaterials and delivery of them into food and pharmaceutical products is of growing importance. In this study, date seed protein hydrolysate (DSPH) was produced through enzymatic hydrolysis using alcalase (30–180 min), and characterized. The hydrolysate was then microencapsulated via spray-drying and incorporated into pan-bread formulation. Enzymolysis time significantly influenced the degree of hydrolysis (1.5–26.5%), free amino acid content, and antioxidant activity of DSPH. DSPH obtained after 120 min of hydrolysis (DSPH-120) was found suitable for microencapsulation. Among the microcapsule powders produced with various carriers (i.e., maltodextrin, gum Arabic, whey protein concentrate (WPC), and pectin), the maltodextrin-WPC-based one was selected for bread fortification, due to its high production yield and favorable physicochemical, functional, and morphological properties. The fortification level (1–5% w/w) impacted the moisture content, water activity, firmness, specific volume, porosity, color indices (for crust and crumb), antioxidant activity, and sensory attributes (especially bitterness) of the fortified breads. Overall, breads fortified with up to 3% microcapsule powder exhibited acceptable physicochemical and sensory characteristics. These findings demonstrate the potential of DSPH as a valuable source of bioactive compounds and antioxidants for fortification of food products, like bread, after microencapsulation. [ABSTRACT FROM AUTHOR]

The use of green solvents, citric acid (CA), and natural deep eutectic solvents (NADES) for the obtention of pectin from wastes (pulp and peel) of Malus domestica was studied. The NADES used comprised citric acid–glucose–water (N1) or lactic acid–glucose–water (N2). The fractions rich in pectin obtained after exposure to NADES showed lower yield (≈4 g/100 g CA vs. ≈ 11 g/100 g CA), equal to or lower degree of methoxylation (53–71 mol/100 mol CA vs. 73 mol/100 mol CA), equal to or greater content of uronic acid (50–63 g/100 g CA vs. 51 g/100 g CA) than those isolated with CA, and the ones obtained from peel were the most thermally stable. These pectins showed greater linearity, shorter branch lengths, and lower arabinose content than those obtained with CA. The neutral sugars present in the highest concentration in all the isolated fractions were arabinose, xylose, galactose, and rhamnose. Glucose was also detected, probably due to contamination with starch. Their aqueous solutions showed pseudoplastic behavior. The effect of ultrasound assistance was preliminarily evaluated in the production of pectic fractions using N2, observing higher yields (13–18 g/100 g), in general, a higher concentration of uronic acid and a higher degree of methoxylation when compared with the extraction without US. They also showed greater arabinose content (less degradative treatment), lower glucose content (increased purity), and higher rhamnogalacturonan I (RG-I) content. It is known that RG-I is linked to pectin bioactivity and rheological behavior. The green solvent techniques assayed allowed obtaining fractions rich in uronic acid with different chemical, thermochemical, and rheological characteristics. In the case of isolation with NADES, the yield was low, but preliminary tests with ultrasound assistance showed that it is possible to overcome this limitation. [ABSTRACT FROM AUTHOR]

AbstractThe effects of four groups of hot-air drying methods, including constant temperature (50 °C) and constant humidity (10%) (CTCH), constant temperature (50 °C) and variable humidity (60%-47%-35%-23%-10%) (CTVH), variable temperature (40 °C-46 °C-52 °C-58 °C-64 °C) and constant humidity (10%) (VTCH), variable temperature (40 °C-46 °C-52 °C-58 °C-64 °C) and variable humidity (60%-47%-35%-23%-10%) (VTVH), on the drying kinetics, product quality and the content of pectin polysaccharides in cell wall of wolfberry were studied. Among them, VTVH showed the highest drying efficiency with the shortest drying time of 13 h, which was 9.52% shorter than that of CTCH, and the highest effective water diffusion coefficient for wolfberries (9.356 × 10−9 m2·min−1). After VTVH drying, samples showed the highest polysaccharides content (46.48%) and rehydration rate (52.24%), as well as the lowest color difference (6.07) and shrinkage rate (66.38%). The content of water-soluble pectin (WSP) in wolfberry was the highest under VTCH drying condition, which was 48.67% higher than that of CTVH drying condition. [ABSTRACT FROM AUTHOR]

Tea plant can enrich a large amount of fluorine (F) in the cell wall of its mature leaves, thus posing the risk of excessive intake of F for tea consumers. This study investigated the effect of foliar calcium (Ca) application (0.05-1 mM) on F accumulation in tea plant leaves by analyzing the association of F with cell wall materials, pectin methylesterification structure, and cell wall genes. Ca spray could effectively reduce the F level, the content of wall carbohydrates (excluding the chelate pectin fraction) and the pectin methylesterification degree in tea plant leaves. Correlation analysis further revealed that the tea leaf F content was positively correlated with most of the cell wall materials. Transcriptomics analysis indicated that the key genes involved in reorganization of cell wall polysaccharides (such as CslE6 , XTH32 , PG , PGIP , PME18 , PMEU1 , and PMEI9) were associated with the variations in F content and cell wall components. All the results suggest that Ca may lessen the tea leaf F level by reducing the accumulation of cell wall materials and intervening the cell wall structure and gene expression. This study provided useful information for reducing the F level and solving the F safety problem in tea plant. [ABSTRACT FROM AUTHOR]

The recovery of polysaccharides (PS) from red grape marc and white grape pomace by enzymatic degradation of their cell walls is an interesting green extraction technique that preserves the structure and bioactivity of PS. The type and dose of enzyme, and the liquid/solid (L/S) ratio in PS extraction were studied using four commercial enzymes. Four different doses per enzyme were used, with tartaric acid as solvent and L/S ratios of 1.3/1 and 4/1 for 24 h at 20 °C, compared with a control. The highest dose of enzyme E1, polygalacturonase + pectin lyase + pectin-methyl-esterase (with the highest activity) was the most effective in the degradation of high and medium molecular weight PS. At the lower L/S ratio, the fact that the highest dose of E1 degraded a higher percentage of high and medium molecular weight PS in the marc was explained by the difference in cell wall deconstruction between pomace and marc. The highest total PS purity was achieved in pomace with E1 at the maximum dose in both ratios, and in marc at the 1.3/1 ratio. The extraction efficiency of total PS was low for all enzymes. In the future, extraction with E1 combined with other green extraction techniques will be studied. [ABSTRACT FROM AUTHOR]

AbstractInfrared microspectroscopy allows for detailed characterization of functional groups at subcellular levels in plants. In this study, barley leaves were inoculated with Blumeria graminis f. sp. hordei (Bgh, adapted) and B. graminis f. sp. tritici (Bgt, nonadapted). Globar-based transmission Fourier transform infrared (gFTIR) microspectroscopy equipped with an upgraded high-resolution focal plane array (FPA) detector which enabled the rapid acquisition of high magnification imaging with a 3.3-μm × 3.3-μm capacity, was employed to quantitatively analyse the cell wall (CW) modification over individual leaf cells in response to attempted penetration at 24 hours post-inoculation. Univariate and multivariate analyses of gFTIR spectra revealed distinct changes in several CW functional groups upon attempted penetration by Bgt, with significant increases in the integrated areas of cellulose, hemicellulose, methyl-esterified pectins and lipid regions compared to cells without penetration. Notably, neither guaiacyl (G) nor syringyl (S) lignin increased significantly in CWs near Bgt penetration sites relative to nonpenetrating controls, though the G/S ratio was higher than in Bgh-penetrated sites. These findings suggest early and rapid CW modifications occur during the nonhost resistance to Bgt. This study also confirms previous results obtained using synchrotron-based FTIR (sFTIR), demonstrating that both gFTIR and sFTIR are valuable for studying plant CW apposition, with gFTIR being more accessible and rapid for imaging over large areas with compatible quality and resolution to sFTIR. [ABSTRACT FROM AUTHOR]

Copyright of Shipin Kexue/ Food Science is the property of Food Science Editorial Department and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Pectin is a complex plant heteropolysaccharide whose structure and function differ depending on its source. In animal feed, breaking down pectin is essential, as its presence increases feed viscosity and reduces nutrient absorption. Soybean meal, a protein-rich poultry feed ingredient, contains significant amounts of pectin, the structure of which remains unclear. Consequently, the enzyme activities required to degrade soybean meal pectin and how they interact are still open questions. In this study, we produced 15 recombinant fungal carbohydrate-active enzymes (CAZymes) identified from fungal secretomes acting on pectin. After observing that these enzymes were not active on soybean meal pectin when used alone, we developed a semi-miniaturized method to evaluate their effect as multi-activity cocktails. We designed and tested 12 enzyme pools, containing up to 15 different CAZymes, using several hydrolysis markers. Thanks to our multiactivity enzymatic approach combined with a Pearson correlation matrix, we identified 10 fungal CAZymes efficient on soybean meal pectin, 9 of which originate from Talaromyces versatilis. Based on enzyme specificity and linkage analysis, we propose a structural model for soybean meal pectin. Our findings underscore the importance of combining CAZymes to improve the degradation of agricultural co-products. [ABSTRACT FROM AUTHOR]

Highlights: This review provides a detailed account of engineered plant cell wall (CW)-mimetic soft materials, which are designed to replicate the intricate composition, structure, and mechanical properties of natural plant CWs. Experimental methods to create CW-like materials are reviewed, and relevant characterization techniques, including mechanical, chemical, structural, and morphological analyses, are discussed. The applications of CW-like materials in several fields, including food packaging, edible films, drug delivery, construction materials, and biocatalysis are highlighted. Plant cell wall (CW)-like soft materials, referred to as artificial CWs, are composites of assembled polymers containing micro-/nanoparticles or fibers/fibrils that are designed to mimic the composition, structure, and mechanics of plant CWs. CW-like materials have recently emerged to test hypotheses pertaining to the intricate structure–property relationships of native plant CWs or to fabricate functional materials. Here, research on plant CWs and CW-like materials is reviewed by distilling key studies on biomimetic composites primarily composed of plant polysaccharides, including cellulose, pectin, and hemicellulose, as well as organic polymers like lignin. Micro- and nanofabrication of plant CW-like composites, characterization techniques, and in silico studies are reviewed, with a brief overview of current and potential applications. Micro-/nanofabrication approaches include bacterial growth and impregnation, layer-by-layer assembly, film casting, 3-dimensional templating microcapsules, and particle coating. Various characterization techniques are necessary for the comprehensive mechanical, chemical, morphological, and structural analyses of plant CWs and CW-like materials. CW-like materials demonstrate versatility in real-life applications, including biomass conversion, pulp and paper, food science, construction, catalysis, and reaction engineering. This review seeks to facilitate the rational design and thorough characterization of plant CW-mimetic materials, with the goal of advancing the development of innovative soft materials and elucidating the complex structure–property relationships inherent in native CWs. [ABSTRACT FROM AUTHOR]

Sugar beet pulp is a byproduct of white sugar production, and it is quite significant in terms of volume. Every year, tens of millions of tons of beet pulp are produced around the world. However, only a fraction of it is currently used, mainly as animal feed. The composition of beet pulp includes plant polysaccharides, such as cellulose, arabinan, and pectin. Through the process of enzymatic hydrolysis, these polysaccharides are converted into technical C6/C5 sugars, which can be further used as a substrate for the microbial synthesis of various substances, including biofuels, organic acids, and other green chemistry molecules. The current study was designed with a primary objective that focused on the development of a strain that had the potential for enhanced productivity and the capacity to produce enzymes suitable for beet pulp hydrolysis. The pelA and abfA genes, which encode pectin lyase and arabinofuranosidase, respectively, in the fungus Penicillium canescens (VKPM F-178), were cloned and successfully expressed in the recipient strain Penicillium verruculosum B1-537 (VKPM F-3972D). New recombinant strains were created using the expression system of the mycelial fungus P. verruculosum B1-537, which is capable of simultaneously producing pectin lyase and arabinofuranosidase, as well as homologous cellulases. The screening of strains for increased enzymatic activity towards citrus pectin, sugar beet branched arabinan, and microcrystalline cellulose revealed that a B4 clone of P. verruculosum exhibited the greatest potential in sugar beet pulp cake hydrolysis. This clone was selected as the basis for the creation of a new enzyme preparation with enhanced pectin lyase, arabinase, and cellulase activities. The component composition of the enzyme preparation was determined, and the results indicated that the enzyme content comprised approximately 11% pectin lyase, 40% arabinofuranosidase, and 40% cellulases. The primary products of the enzymatic hydrolysis of the unpretreated beet pulp cake were arabinose and glucose. The degree of arabinan and cellulose conversion was observed to be up to 50% and 80%, respectively, after a period of 48 to 72 h of hydrolysis. The new B4 preparation was observed to be highly efficacious in the hydrolysis of beet cake at elevated concentrations of solids (up to 300 g/L) within the reaction mixture. The newly developed strain, as a producer of pectin lyase, arabinofuranosidase, and cellulase complexes, has the potential to be utilized for the bioconversion of sugar beet processing wastes and for the efficient generation of highly concentrated solutions of technical sugars for further implementation in processes of microbial synthesis. [ABSTRACT FROM AUTHOR]

The objective of this study is to investigate the effects of carvacrol on the postharvest storage quality and cell wall metabolism of the 'Guichang' kiwifruit. For this purpose, the 'Guichang' kiwifruit is selected as the test material and treated with 0.03 mg/mL of a carvacrol solution for dipping. The storage quality and cell wall metabolism of the fruit are then evaluated under ambient conditions (20 ± 1 °C). The results indicate that treatment with carvacrol effectively reduces the postharvest respiration rate and weight loss in the kiwifruit, while preserving the levels of vitamin C (VC), soluble protein, total phenols, flavonoids, soluble solids, solid–acid ratio, and soluble pectin. Additionally, it delays the decline in the starch content and mitigates the increase in soluble sugars. Furthermore, carvacrol significantly decreases amylase activity and inhibits the elevation of polygalacturonase (PG), pectin methylesterase (PME), β-galactosidase (β-Gal), and cellulase (Cx) activity. Consequently, this treatment effectively maintains fruit firmness as well as protopectin (PP) and cellulose content at elevated levels. A correlation analysis shows that firmness is highly and negatively correlated with the cell wall degrading enzymes PG, PME, β-Gal, Cx, and α-L-Af, with R values of −0.88, −0.83, −0.98, −0.94, and −0.93, respectively. The negative correlation values for the control group are all lower than 0. In conclusion, treatment with carvacrol effectively preserves a high level of postharvest ripening quality in the kiwifruit, attenuates the metabolic processes of the cell wall, and delays fruit softening and senescence. [ABSTRACT FROM AUTHOR]

Simple Summary: Molybdenum (Mo) is an essential trace element for plant growth and development, and is currently widely used in crop fertilizers. The plant cell wall is the first barrier to prevent the invasion of diseases, and provide protection and support for plant growth. We systematically evaluated the regulatory effects of Mo on tobacco plant growth and cell wall biosynthesis. The application of Mo increased the Mo content, molybdase gene expression, and biomass, and thus promoted tobacco growth. The quantity of C-O-C, -COOH, C-H, and N-H functional groups, and the contents of cellulose, hemicellulose, lignin, protopectin, and soluble pectin were increased in the cell wall of Mo-treated plants. The metabolomics results revealed that Mo could regulate the synthesis of metabolic substances through key metabolic pathways such as galactose metabolism, and arginine and proline biosynthesis. Our findings reveal that Mo has beneficial effects on plant growth and cell wall thickening, and provides important clues for the further investigation of trace elements. Molybdenum (Mo) is widely used as a micronutrient fertilizer to improve plant growth and soil quality. However, the interactions between cell wall biosynthesis and molybdenum have not been explored sufficiently. This study thoroughly investigated the regulatory effects of different concentrations of Mo on tobacco cell wall biosynthesis from physiological and metabolomic aspects. The results indicate that Mo treatment increased the Mo content of tobacco variety K326. Moreover, it significantly up-regulated the gene expression levels of molybdases (NR, AO, SO, XDH) and molybdate transporters in tobacco, whereby the gene expression levels of NR were upregulated by 28.48%, 52.51%, 173.05%, and 246.21%, respectively; and MOT1 and MOT2 were upregulated by 21.49/8.67%, 66.05/30.44%, 93.05/93.26%, and 166.11/114.29%, respectively. Additionally, Mo treatment regulated the synthesis of related enzymes, effectively promoted plant growth, and significantly increased biomass and dry matter accumulation, with the biomass in the leaves increasing significantly by 30.73%, 40.72%, 46.34%, and 12.88%, respectively. The FT-NIR spectroscopy results indicate that after Mo was applied to the soil, the quantity of C-O-C, -COOH, C-H, and N-H functional groups increased. Concurrently, the contents of cellulose, hemicellulose, lignin, protopectin, and soluble pectin in the leaves significantly increased, wherein the content of soluble pectin and hemicellulose increased significantly by 31.01/288.82%, 40.69/343.43%, 69.93/241.73%, and 196.88/223.26%, respectively. Furthermore, the cell walls thickened, increasing the ability of the plant to withstand disturbances. The metabolic network diagrams indicate that Mo regulated galactose metabolism, and arginine and proline acid biosynthesis. The contents of carbohydrates, spermidine, proline, quinic acid, IAA, flavonoids, and other substances were increased, increasing the levels of polysaccharides and pectin within the cell wall, controlling lignin production, and successfully enhancing resistance to abiotic stress. These results offer important perspectives for further investigations into the role of trace elements. [ABSTRACT FROM AUTHOR]

This study examines the impact of titanium and copper ion modifications on the properties of hybrid hydroxyapatite/chitosan granules, which serve as components of novel injectable bone substitutes - biomicroconcretes. In addition to the hybrid granules, the powdered phase of the composites comprises highly reactive α-tricalcium phosphate (α-TCP) powder. The utilization of a mixture consisting of citrus pectin and disodium phosphate as the liquid phase of bone substitutes facilitated the development of easily mouldable, fully injectable biomicroconcretes based on calcium phosphate, characterized by distinct properties. The resulting biomicroconcretes demonstrated favourable cohesion and setting times falling within acceptable parameters. Furthermore, the incorporation of citrus pectin into the liquid phase significantly augmented the mechanical strength of the materials. The unique attributes of biomicroconcretes containing citrus pectin arise from the presence of both a dual setting system and a double hybrid system. The dual setting mechanism, stemming from the hydrolysis of α-TCP and the crosslinking of citrus pectin in the presence of Ca2⁺ ions, yielded materials distinguished by excellent cohesion and chemical stability. Conversely, the double hybrid system emerged from the coexistence of hybrid granules and interactions between polycationic chitosan within the hybrid granules and polyanionic citrus pectin. All obtained biomicroconcretes exhibited in vitro bioactivity, positioning them as promising candidates for further biological investigations. Notably, the integration of antibacterial copper ions into hybrid hydroxyapatite/chitosan granules significantly enhances their potential utility as bone substitute materials, effectively reducing the risk of S. aureus and E. coli infection during surgical procedures. It has been found that titanium modified composites reduced adhesion of S. aureus but did not reduce the adhesion of E. coli cells. This research validates the advantageous properties of the synthesized ceramic-based biomaterials and sets the stage for subsequent in vitro and in vivo studies. [ABSTRACT FROM AUTHOR]

In response to the restrictions imposed by their epiphytic habit, orchids have developed structural traits that allow greater efficiency in water uptake and use, such as a complex adventitious root system with velamen. The composition of cell wall of this specialized epidermis can be altered according to the substrate to which it is fixed, influencing wall permeability, absorption, and storage of water in roots. The current study aimed to evaluate the cell wall composition of adventitious roots of Vanilla phaeantha (Orchidaceae) that grow attached to the phorophyte, fixed in the soil, or hung free. Immunocytochemical analyses were used to determine the protein, hemicellulose, and pectin composition of the cell walls of aerial and terrestrial roots. We observed that pectins are present in the different tissues of the aerial roots, while in the terrestrial roots, they are concentrated in the cortical parenchyma. The deposition of xyloglucans, extensins, and arabinogalactans was greater in the epidermis of the free side of the roots attached to the phorophyte. The strong labeling of pectins in aerial roots may be related to the influx of water and nutrients, which are generally scarce in this environment. The arrangement of hemicelluloses and proteins with the pectins may be associated with increased cell rigidity and sustainability, a feature of interest for the aerial roots. In summary, the habit of roots can interfere with the non-cellulosic composition of the cell walls of V. phaeantha, possibly related to changes in cell functionality. [ABSTRACT FROM AUTHOR]

The aim of the study was to determine the effect of the recommended (6.5 mg/kg) or enhanced (13 mg/kg) level of CuNPs in the diet in combination with different types of dietary fibre – cellulose (control), inulin, pectin, or psyllium on the Cu biodistribution and level of selected minerals parameters in the blood of rats. Rats were randomly divided into 10 groups. The first two groups were fed control diets containing cellulose and a mineral mixture with standard or enhanced content of CuCO3. Experimental groups were fed a diet supplemented with CuNPs (6.5 or 13 mg/kg) and combined with different types of fibre (cellulose, pectin, inulin, or psyllium). After the feeding period blood, liver, brain, and thigh samples were collected. In the samples of water, diet, urine, faeces, liver, brain, and thigh the Cu content was determined to assess Cu biodistribution in the body. Additionally, the concentrations of minerals (Cu, P, Ca, Mg, Fe, and Zn) in the blood plasma samples were measured. The replacement of CuCO3 with CuNPs in the diet beneficially influenced the biodistribution of Cu in the body by reducing its excretion, improving its digestibility, and utilization, reducing its accumulation in the brain and muscle, and increasing levels of Ca, P, Mg, Zn and Fe in the blood. Increasing the level of CuNPs in the diet increased total Cu intake. The addition of pectin, inulin and psyllium to the diet with a high content of CuNPs significantly increased the excretion of Cu, with no negative effect on its digestibility, and utilization, and prevented its excessive accumulation in the brain and muscle of rats, especially in the case of inulin. The results suggest that the addition of dietary fibre to the diet of rats ensures homeostasis of this element in the case of excessive intake of CuNPs by modifying the bioavailability of Cu. [ABSTRACT FROM AUTHOR]

Although angiosperm plants generally react to immunity elicitors like chitin or chitosan by the cell wall callose deposition, this response in particular cell types, especially upon chitosan treatment, is not fully understood. Here we show that the growing root hairs (RHs) of Arabidopsis can respond to a mild (0.001%) chitosan treatment by the callose deposition and by a deceleration of the RH growth. We demonstrate that the glucan synthase‐like 5/PMR4 is vital for chitosan‐induced callose deposition but not for RH growth inhibition. Upon the higher chitosan concentration (0.01%) treatment, RHs do not deposit callose, while growth inhibition is prominent. To understand the molecular and cellular mechanisms underpinning the responses to two chitosan treatments, we analysed early Ca2+ and defence‐related signalling, gene expression, cell wall and RH cellular endomembrane modifications. Chitosan‐induced callose deposition is also present in the several other plant species, including functionally analogous and evolutionarily only distantly related RH‐like structures such as rhizoids of bryophytes. Our results point to the RH callose deposition as a conserved strategy of soil‐anchoring plant cells to cope with mild biotic stress. However, high chitosan concentration prominently disturbs RH intracellular dynamics, tip‐localised endomembrane compartments, growth and viability, precluding callose deposition. Summary statement: The root hairs (RHs) of Arabidopsis, when exposed to elicitor chitosan, deposit callose and change the growth rate. This is accompanied by altered signalling, gene expression, and is linked to altered pectin methylation state. Our research highlights the evolutionarily conserved role of RHs in environmental sensing. [ABSTRACT FROM AUTHOR]

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The effects of different mild drying conditions using various drying methods [freeze drying (FD), vacuum drying at 15 kPa pressure (VD15), vacuum drying at 1 kPa pressure (VD1), convective drying (CD), and infrared drying (IRD)] on drying kinetics, proximate composition, yield of extracted pectin, methoxyl content, sugar content, total carotenoids content, antioxidant potential, and color parameters of carrot wastes were examined experimentally. CD was the shortest drying treatment compared to the other drying processes, at 270 min, followed by IRD, VD1, FD, and VD15. The results showed a higher retention of pectin and carotenoids in CD-dried samples. Moreover, along with VD1, CD was able to maintain sucrose and antioxidant potential to a greater extent than other methods. Based on color parameters, FD and IRD had the most significant changes in relation to CIELab values, with ∆E* values close to 33 and 34 units, whereas VD15, VD1, and CD had values (without significant differences) close to 16, 18, and 21 units, respectively. Therefore, the current findings suggest that a short period of exposure of the waste to mild drying temperature conditions is essential for obtaining high-quality waste with potential for use in the food industry. [ABSTRACT FROM AUTHOR]

Polysaccharides like starch, chitosan, and pectin are attractive for removing heavy metal ions from water. Chitosan (n+) is mixed with pectin (n−) to enhance ion adsorption from aqueous media. This study involves two parts. First, 1 g/L stock solutions of pectin and chitosan at pH 5 are prepared and used to create polyelectrolyte complexes (PECs) with varying molar charge ratios (n−/n+). Pectin is added to stirred chitosan solutions to form PECs, relying on ionic interactions between chitosan's amino groups and pectin's carboxyl groups. However, the resultant PEC concentration is insufficient for effective heavy metal ion removal. In response, the second part of the study focuses on a specific PEC with n−/n+ of 0.84. The stock solution concentration is increased to 5 and 10 g/L at pH 5, enhancing efficiency and forming a gel. The gel dispersion is freeze‐dried, and the resultant PECs are used for adsorption experiments with Cd2+, Ni2+, Fe2+/3+, Mn2+, and Cu2+ sulfate solutions. Adsorption rates are in the order Cu2+ > Fe2+/3+ > Cd2+ > Ni2+ > Mn2+ for a 20 mg/L salt concentration, indicating high PEC affinity for heavy metal ions. [ABSTRACT FROM AUTHOR]

The effects of CaCl2 addition before (PreCa) or after (PostCa) heating pea protein–pectin dispersions on the formed gel's rheological and microstructural properties were investigated. Isothermal titration calorimetry (ITC) revealed that CaCl2 bound both pea proteins and pectins through a spontaneous exothermic reaction and pectin exhibited a stronger binding affinity to CaCl2. In PreCa gels, low levels of CaCl2 (5 and 10 mM) increased the gel elasticity (increase in the storage modulus, G′) and their microstructural compactness. However, higher CaCl2 levels (15 and 25 mM) decreased gels' elasticity, likely due to diminished hydrogen bonds formed in the cooling stage, resulting in gels with larger voids and fewer interconnections between the protein and pectin phases. In PostCa gels, their elasticity increased with the CaCl2 content, a rheological change associated with the formation of denser microstructures. The addition of 25 mM CaCl2 decreased β-sheet and increased α-helix and random coil structures. Hydrogen bonding and electrostatic and hydrophobic interactions contributed to gel formation and stability in both PreCa and PostCa gels, whereas disulfide bonds had negligible effects. This study highlights the role of CaCl2 in modulating pea protein–pectin gels' properties and microstructures for the development of gel-like foods with diverse textures and mouthfeels. [ABSTRACT FROM AUTHOR]

Since only a limited number of fruit sources are utilized for commercial pectin production, there is a growing need to explore new and unique sources in light of the recent rise in industrial demand for this polymer. In this study, pectin from the pomace of the Phyllantus acidus fruit was extracted, optimized using response surface methodology and characterized for the first time in relation to its physicochemical characteristics and techno-functional properties. A maximized yield of 6.54 ± 0.83% was obtained through optimized conditions of a 180 min extraction time, an extraction solvent pH of 1.5 and a solid-liquid ratio of 1:50. Spectroscopic analysis confirmed a high-methoxyl pectin and intrinsic viscosity measurements revealed that the pectin had a molecular weight of 33389.58 g/mol. The emulsion stability of the extracted pectin (100%) was significantly greater than values reported in the literature due to its high protein content (12.56%). Additionally, it displayed excellent antioxidant properties due to its high total phenolic content of 33.10 mg gallic acid equivalent (GAE)/g. The 2,2-diphenyl-1-picrylhydrazyl (DPPH) assay showed that the pectin had a scavenging rate of 94% compared to the 97% of ascorbic acid and the 66% of commercial pectin. Furthermore, ferric reducing antioxidant power (FRAP) analysis revealed that compared to ascorbic acid, the extracted pectin had more than a 10-time higher relative FRAP value (45.48%) than commercial pectin (3.95%). The study's results highlight Phyllantus acidus as a promising and alternative source of pectin with potential applications in the food industry. [ABSTRACT FROM AUTHOR]

Cassava root cortex (CRC), which represents 10–12% of the weight of the cassava root, is a residue rich in pectin, a heteropolysaccharide with potential for food and pharmaceutical applications. This study aimed to develop optimal conditions for pectin extraction from CRC using hydrochloric acid and water, aiming to observe the behavior and characteristics acquired in each extraction. For this purpose, a central composite rotational design (CCRD) was used to observe the action of dependent variables (solvent: CRC flour proportion, temperature, and time) on the dependent variables (yield, degree of esterification, and galacturonic acid content). CRC flour presented significant levels of phenolic compounds (2088.78 mg GAE/100 g), anthocyanins (71.86 mg/100 g), and flavonoids (49.99 mg/100 g), besides low water content (4.91%). Aqueous and acidic extraction assays showed that acidic extraction resulted in higher yields (71.83%), with pectins of low (< 50%) and high (> 50%) methoxylation. Furthermore, it was observed that the interaction of time and temperature variables had greater weight in the regression coefficients, presenting significant effects in all treatments. Therefore, our results highlighted the best conditions for aqueous extraction (70 °C, 60 min, and proportion of 1:40) and acidic extraction (70 °C, 60 min, and proportion of 1:20), showing that the optimized pectin from CRC has good potential for use in various industrial applications. [ABSTRACT FROM AUTHOR]

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Fruit waste (FW), mainly from agroindustry, is currently left behind in landfills despite its rich composition. The bioactive compounds (e.g., oils, polyphenols), carbohydrates, and lignin present in this biomass type require comprehensive characterization (i.e., identification and quantification) before they can be used as raw materials in biorefineries. This review collected information from scientific papers on FW compositional analysis methods and characterization data; the information needs to be compiled in a systematic, standardized, and comprehensive way to understand and quantify the true potential of FW as feedstocks for biorefineries. The information gathered in this review allowed us to identify the biomass fractions that could be valorized further depending on the kind of FW (peels, seeds, or seed vessels, and pomace or mixed residues). Fruit waste differs from conventional lignocellulosic biomass due to the presence of higher amounts (>5%) of extractives – pectin, and starch. This review describes current compositional analysis methodologies to identify possible strengths and weaknesses that could affect the adequate selection of valorization platforms. As no current methodology allows the composition of FW to be described thoroughly, this work identifies procedures applicable to biorefineries that use FW. Possible improvements are suggested to fill methodological gaps in the quantification of samples with large amounts of extractives and pectin. The standardization of methods for FW's quantification is fundamental for the adequate integration of different valorization platforms into biorefineries. It is essential to consider all the substances present in FW to exploit fully their potential for new value‐added molecules, including oils, polyphenols, and pectin. [ABSTRACT FROM AUTHOR]

Pectin is widely spread in nature and it develops an extremely complex structure in terms of monosaccharide composition, glycosidic linkage types, and non-glycosidic substituents. As a non-digestible polysaccharide, pectin exhibits resistance to human digestive enzymes, however, it is easily utilized by gut microbiota in the large intestine. Currently, pectin has been exploited as a novel functional component with numerous physiological benefits, and it shows a promising prospect in promoting human health. In this review, we introduce the regulatory effects of pectin on intestinal inflammation and metabolic syndromes. Subsequently, the digestive behavior of pectin in the upper gastrointestinal tract is summarized, and then it will be focused on pectin's fermentation characteristics in the large intestine. The fermentation selectivity of pectin by gut bacteria and the effects of pectin structure on intestinal microecology were discussed to highlight the interaction between pectin and bacterial community. Meanwhile, we also offer information on how gut bacteria orchestrate enzymes to degrade pectin. All of these findings provide insights into pectin digestion and advance the application of pectin in human health. [ABSTRACT FROM AUTHOR]

[Objective] In order to provide technical support for further improving the aging quality of core tobacco raw materials, the suitable packing densities for natural aging of different grades of tobacco leaves were explored. [Method] Hongda B2F, C3F and X2F redried strips were selected as test materials, and the packing density of each redried strips was set with 4 gradients, namely 180,190,200 and 210 kg/carton (0.514 m³). The effects of different packing densities on the contents of aroma components, cellulose, lignin, pectin, plastid pigment and sensory quality of aged strips were analyzed after the above redried strips were aged for 600 d under the same storage environment.[Result]The contents of some chemical components and sensory quality showed great differences after the same redried strips were naturally aged for 2 years with different packing densities. Comprehensively compare the differences of aroma components, cellulose, lignin, pectin, plastid pigments and sensory quality of aged strips with different packing densities, the suitable packing density of B2F,C3F and X2F redried strips was 200,180 and 190 kg/carton respectively.[Conclusion]The packing density of redried strips had a great impact on its aging effect, and different packing densities were suitable for aging of different grades of redried strips. [ABSTRACT FROM AUTHOR]

Pectin, a polysaccharide, is widely used as a gelling and thickening agent in the food industry. This study undertook optimization of pectin extraction from the peels of Baccaurea ramiflora Lour. (Burmese grape or lotkon), an abundantly grown wild fruit in Bangladesh. We applied the Box–Behnken Design of Response Surface Methodology with varied processing parameters including pH, time, and temperature. The Response Surface Methodology, employing a second‐order polynomial model, successfully optimized the extraction conditions for the maximum pectin yield. The model predicted a pectin yield of 10.73%, which closely matched the experimental yield of 10.56%. The optimal conditions for pectin extraction were determined as pH (2.4), extraction time (56 min), and temperature (76°C). Further analyses of the extracted pectin under optimized conditions confirmed its excellent potential for food applications. The pectin was characterized by its moisture content (10.42%), water activity (0.51), ash content (3.41%), equivalent weight (769.23 mg/mole), methoxyl content (7.75%), anhydrouronic acid content (66.88%), degree of esterification (65.79%), and acetyl value (0.39%). These determined parameters strongly support that the pectin extracted from the peels of Burmese grapes is of good quality. [ABSTRACT FROM AUTHOR]

Bacterial cellulose (BC) is a subject of interest for researchers due to its advantageous characteristics, including a straightforward manufacturing process, biocompatibility, and extensive modification potential. The hydrophilic nature of the material is beneficial in some applications, yet a limiting factor in others. This study aimed to develop BC-based materials with goFogureod moisture resistance. The modification of bacterial cellulose (BC) using apple powder, stearic acid, or a combination of these modifiers resulted in the formation of a range of materials, some of which had their surfaces additionally functionalised by coating with a mixture of apple powder and stearic acid (HSt). The nature and type of changes were confirmed by FTIR and theoretical analysis, which was conducted by modelling the interaction between cellulose and homogalacturonan or rhamnogalacturonan using SCIGRESS v.FJ 2.7 software. Changes in hydrogen bonding resulting in a weakening of the interactions between cellulose and water in the presence of pectin were demonstrated by both empirical data and modelling. The effectiveness of BC functionalisation was confirmed by material wettability. The water contact angle changed from 38° for the unmodified material to 125° for the material obtained by modification of the bacterial cellulose with glycerol followed by modification with a mixture of HSt at a concentration of 10% and AP at a concentration of 60%. The modifications produced a material with a robust hydrophobic surface. The results suggest that the surface roughness may not be the primary factor influencing the hydrophilicity or hydrophobicity of these materials but that it is more likely to be related to the interactions of components. None of the tested materials demonstrated antimicrobial activity against Escherichia coli, Bacillus subtilis, Staphylococcus aureus, Aspergillus niger, or Candida albicans. [ABSTRACT FROM AUTHOR]

Objective: А method has been developed for extracting modified pectin from plant raw materials by using microwave radiation at the stage of washing. Methods: The rheological properties of 5.0% aqueous solutions of apple pectin obtained by exposure to microwave radiation of various powers: 300, 450 and 600 W, as well as pectins obtained by the traditional method at temperatures of 25, 40, 55, 70°C were investigated. Results and Discussion: It is shown that the use of microwave radiation can improve the method of obtaining pectins by increasing the yield of pectins and regulating their structure and properties. The rheological properties of concentrated aqueous solutions of pectins obtained by exposure to microwave radiation of various powers have been studied. It is shown that all studied systems of pectin solutions are non-Newtonian fluids with a pseudoplastic type of viscous flow anomaly, determined by the values of the microwave energy. The values of the apparent activation energies of the viscous flow of solutions, which are an indirect characteristic of the strength of the structures of the system, have been estimated. Data was obtained on the structure and changes in the structure of their concentrated solutions under the action of external forces and temperature in the course of a viscous flow. Conclusions: It is shown that the power values оf microwave radiation are the main factor determining the structure of molecular matrices of pectins and the structure of their concentrated aqueous solutions. [ABSTRACT FROM AUTHOR]

Background and Aims The cell walls of charophytic algae both resemble and differ from those of land plants. Cell walls in early-diverging charophytes (e.g. Klebsormidiophyceae) are particularly distinctive in ways that might enable survival in environments that are incompatible with land-plant polymers. This study therefore investigates the structure of Klebsormidium polysaccharides. Methods The 'pectin' fraction (defined by extractability) of Klebsormidium fluitans , solubilized by various buffers from alcohol-insoluble residues, was digested with several treatments that (partly) hydrolyse land-plant cell-wall polysaccharides. Products were analysed by gel-permeation and thin-layer chromatography. Key Results The Klebsormidium pectic fraction made up ~30–50 % of its alcohol-insoluble residue, was optimally solubilized at pH 3–4 at 100 °C, and contained residues of xylose ≈ galactose > rhamnose > arabinose, fucose, mannose and glucose. Uronic acids were undetectable, and the pectic fraction was more readily solubilized by formate than by oxalate, suggesting a lack of chelation. Some land-plant-targeting hydrolases degraded the Klebsormidium pectic fraction: digestion by α- l -arabinanase, endo-β-(1→4)- d -xylanase and α- d -galactosidase suggests the presence of β-(1→4)-xylan with terminal α- l -arabinose, α- d -galactose and (unexpectedly) rhamnose. 'Driselase' released oligosaccharides of xylose and rhamnose (~1:1), and graded acid hydrolysis of these oligosaccharides indicated a 'rhamnoxylan' with rhamnose side-chains. Partial acid hydrolysis of Klebsormidium pectic fraction released rhamnose plus numerous oligosaccharides, one of which comprised xylose and galactose (~1:2 Gal/Xyl), suggesting a galactoxylan. Lichenase was ineffective, as were endo-β-(1→4)- d -galactanase, endo-β-(1→4)- d -mannanase, β- d -xylosidase and β- d -galactosidase. Conclusions Klebsormidium pectic fraction possesses many land-plant-like linkages but is unusual in lacking uronic acid residues and in containing rhamnoxylan and galactoxylan domains. Uronic acids allow land-plant and late-diverging charophyte pectins to form Ca2+-bridges, facilitating cell-wall polymer association; their absence from Klebsormidium suggests that neutral heteroxylans rely on alternative cross-linking mechanisms. This lack of dependence on Ca2+-bridges might confer on Klebsormidium the ability to grow in the acidic, metal-rich environments that it tolerates. [ABSTRACT FROM AUTHOR]

Cell walls play essential roles in cell recognition, tissue adhesion, and wound response. In particular, pectins as cell-adhesive agents are expected to play a key role in the early stages of grafting. To test this premise, this study focused on examining the dynamics of the accumulation and degree of methyl-esterification of pectic polysaccharides at the graft junctions using tomato autografts as an experimental model. Monosaccharide analysis showed a marked increase in homogalacturonan from 25% to 32 or 34% at the junction zones early after grafting. In addition, a decrease in the degree of homogalacturonan methyl-esterification up to 38% in the scion and 64% in the rootstock was observed in the first few days after grafting, accompanied by an increase in pectin methyl-esterase activity of up to 20–30% in the tissues surrounding the graft junction. These results shed light on the role of homogalacturonan in grafting and reinforce the key function of pectin as one of the most relevant cell wall components during the grafting process. [ABSTRACT FROM AUTHOR]

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SUMMARY The plant cell wall is the first barrier against pathogen invasion. Fusarium solani is the primary pathogen responsible for apple replant disease. In this study, we identified an MYB protein, MdMYB54, which interacts with the positive regulator of F. solani resistance, MdERF114, and confers apple‐increased tolerance against F. solani. The cellulose synthetase (CESA) gene MdCesA6 and pectin lyase‐like (PLL) genes MdPLL8 and MdPLL12 were screened as three potential downstream target genes of MdMYB54 using DAP‐seq. The results of electrophoretic mobility shift and yeast one‐hybrid assays showed that MdMYB54 directly binds to the promoters of MdCesA6, MdPLL8, and MdPLL12 in vivo and in vitro. Dual‐luciferase and β‐glucuronidase assays showed that MdMYB54 activates the expression of these genes. The cellulose content and pectin lyase activity of MdMYB54‐overexpressed roots were significantly higher than those of wild‐type plants under F. solani treatment but were the opposite in MdMYB54‐RNAi roots. The deposition of cellulose enhanced the physical barrier of the plant cell wall, whereas the activation of pectin lyase promoted the formation of oligogalacturonides and the production of reactive oxygen species. Overexpression of MdCesA6, MdPLL8, and MdPLL12 in the root system enhanced the tolerance of apple to F. solani. The direct interaction of MdERF114 with MdMYB54 enhanced MdMYB54‐mediated cell wall defense response. These results suggest that modifying these candidate genes may provide a strategy for improving the resistance of apple to F. solani. [ABSTRACT FROM AUTHOR]

Pectate lyases (PL), as important polysaccharide lyases, play an important role in the infection of host plants by pathogenic. A previous study found that the PL gene CP966_RS08110 was up-regulated in the interaction between Streptomyces galilaeus 5T-1 and potatoes. In this study, S. galilaeus 5T-1 was used as the study object, and its gene function was investigated using bioinformatics analysis, prokaryotic expression, and CRISPR-Cas9 technology. The previous results showed that the pectate lyase CP966_RS08110 gene of Streptomyces galilaeus 5T-1 was up-regulated in the pathogenic process. In this study, the CP966_RS08110 gene was cloned from the genomic DNA of S. galilaeus 5T-1. It encoded for a 415-residue protein with a complete PL-6 superfamily domain and Pec_lyase_C domain, which belongs to the PL1 family. The soluble protein encoded by CP966_RS08110 was obtained successfully, which has high pathogenicity after inoculating healthy potatoes. The mutant strain △PL5T-1 with CP966_RS08110 gene deletion was successfully obtained, and its colony morphology and pigment were not significantly different from that of wild strains, but its growth rate was slowed down, moreover, the hyaline circle formed by the mutant strain ΔPL5T-1 using pectin was significantly smaller than wild strain, and the deletion of this gene affected the infestation rate of S. galilaeus 5T-1. Our results confirm that the CP966_RS08110 gene was the pathogenic factors and played a key role in process of infecting and causing potato common scab, which laid foundation for understanding the pathogenic mechanism of S. galilaeus 5T-1. [ABSTRACT FROM AUTHOR]

AbstractPectin, a complex dietary fiber, constitutes a key structural component of the cell walls of numerous edible plant products. It is resistant to digestion by human enzymes and undergoes depolymerization and saccharification in the gastrointestinal tract through the action of carbohydrate-active enzymes (CAZymes) produced by gut microbiota. This enzymatic breakdown generates intermediate structural fragments, which are subsequently converted into pectin oligosaccharides (POS) and monosaccharides. POS exhibit prebiotic properties and have demonstrated potential health benefits, including anti-carcinogenic effects, mucoadhesive capabilities, and the promotion of beneficial gut bacterial growth. However, the current understanding of the molecular structure of pectin and its degradation dynamics remains fragmented within the literature, impeding progress in dietary fiber intervention research and the development of personalized nutrition approaches. This review aims to provide a comprehensive overview of the structural features of pectin and the intricate breakdown mechanisms orchestrated by CAZymes. It underscores the complex architecture of pectin that influences its breakdown dynamics and specifies the enzymatic requirements for the cleavage of its diverse structural components. These insights complement our accompanying review on the structure-function relationships between pectin and the human gut microbiota, previously published in this journal. [ABSTRACT FROM AUTHOR]

Citrus peels are produced in large quantities as a by-product of beverage production, leading to underutilization of waste. Sitaya agrihorti citrus is one of the citrus varieties used in the beverage industry because of its sweet taste. Wasted sitaya citrus peels contain components such as pectin. Microwaveassisted extraction (MAE) is a well-known innovative method, currently widely used in pectin extraction due to its efficiency and reduced processing time compared to conventional methods. This study used MAE at different power levels: 360, 450, 540, 630, and 720W, each applied for two minutes. The extracted pectin was evaluated for key properties, including equivalent weight, methoxyl content, galacturonic acid content, degree of esterification, and water content. This study aims to determine the effect of microwave power on pectin yield and quality. The results showed that microwave power significantly affected pectin yield (p < 0.01), with the highest yield of 12.103% obtained at 720W power. However, variations in microwave power did not significantly affect the physical or chemical characteristics of pectin extracted from Sitaya citrus peel. This study concluded that MAE is an effective extraction method for producing pectin from citrus peel waste, which offers a sustainable approach to agro-industrial waste management. The findings highlight the potential for increasing the value of orange peel through an efficient extraction process, contributing to economic and environmental sustainability while creating value-added products. [ABSTRACT FROM AUTHOR]