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The germination process of seeds is influenced by the interplay between two opposing factors, pectin methylesterase (PME) and pectin methylesterase inhibitor (PMEI), which collectively regulate patterns of pectin methylesterification. Despite the recognized importance of pectin methylesterification in seed germination, the specific mechanisms that govern this process remain unclear. In this study, we demonstrated that the overexpression of GhPMEI53 is associated with a decrease in PME activity and an increase in pectin methylesterification. This leads to seed cell wall softening, which positively regulates cotton seed germination. AtPMEI19, the homologue in Arabidopsis thaliana, plays a similar role in seed germination to GhPMEI53, indicating a conserved function and mechanism of PMEI in seed germination regulation. Further studies revealed that GhPMEI53 and AtPMEI19 directly contribute to promoting radicle protrusion and seed germination by inducing cell wall softening and reducing mechanical strength. Additionally, the pathways of abscicic acid (ABA) and gibberellin (GA) in the transgenic materials showed significant changes, suggesting that GhPMEI53/AtPMEI19-mediated pectin methylesterification serves as a regulatory signal for the related phytohormones involved in seed germination. In summary, GhPMEI53 and its homologs alter the mechanical properties of cell walls, which influence the mechanical resistance of the endosperm or testa. Moreover, they impact cellular phytohormone pathways (e.g., ABA and GA) to regulate seed germination. These findings enhance our understanding of pectin methylesterification in cellular morphological dynamics and signaling transduction, and contribute to a more comprehensive understanding of the PME/PMEI gene superfamily in plants.

The increasing impact of climate change poses a serious threat to olive cultivation, particularly through environmental stresses such as ultraviolet-B (UV-B) radiation. This study investigates the use of pollen as a marker to discriminate the UV-B tolerance of four Italian olive cultivars (Frantoio, Leccino, Olivastra Seggianese, and Pendolino). Pollen grains were exposed to UV-B radiation at varying durations (1, 2 and 3 h) and distances (10, 20, 30 and 40 cm) to evaluate viability, germination rate, pollen tube length, and cell wall composition, including the distribution of key structural elements such as pectins, cellulose, callose, arabinogalactan proteins, and polysaccharide-synthesizing enzymes. Results indicate that UV-B stress effects are highly cultivar-specific and exposure-dependent. Frantoio and Leccino show higher sensitivity to short-term, high-intensity UV-B, while Pendolino demonstrates greater resistance to prolonged exposure but unexpected sensitivity to low-intensity, short-duration UV-B. This multidimensional response underscores the complex interaction between cultivar and UV-B stress. These findings contribute to the sustainability of olive cultivation under changing environmental conditions by identifying more resilient cultivars.

We tested the effects of galactoglucomannan oligosaccharides (GGMOs) and/or cadmium (Cd) on peroxidase activity and the proteome in maize (Zea mays L.) roots and leaves. Our previous work confirmed that GGMOs ameliorate the symptoms of Cd stress in seedlings. Here, the plants were hydroponically cultivated for 7 days, and the protein content and peroxidase activity were estimated in intracellular, neutral cell wall, and acidic cell wall protein fractions. The peroxidase activity varied between the plant organs as well as among the fractions and treatments. The GGMOs in the presence of Cd did not significantly influence content of peroxidases but modulated their activity, which implies posttranslational regulation. The changes in the content of various proteins (e.g., related to the defence reactions, cell wall structure/metabolism, and activation of plant hormones) caused by GGMOs and Cd indicate possible protective mechanisms that improve the vitality of maize seedlings exposed to metal stress. GGMOs partially reverted Cd-induced protein disbalance, which was a reoccurring phenomenon of mitigation in leaves.

The involvement of jasmonic acid (JA) in the rice’s response to cadmium (Cd) stress is well recognized, though the underlying mechanisms remain unclear. In this study, exposure to Cd stress rapidly elevated endogenous JA concentrations in rice roots, meanwhile, a mutant coleoptile photomorphogenesis 2 (cpm2) which produces less JA, was more sensitive to Cd stress than its wild type (WT). JA mitigated Cd toxicity by decreasing Cd absorption in root cell wall and shoot, which was achieved by up-regulating the expression of the Cd-chelation and efflux-related genes such as OsHMA3, OsABCG36 and OsCAL1; down-regulating the transcript level of the Cd uptake and translocation-related genes, including OsHMA2, OsCCX2, OsNRAMP1/5, and OsZIP5/7. Additionally, a reduction in hemicellulose content was observed in the root cell wall. Further analysis indicated that the mitigation effect of JA on Cd accumulation was dependent on the inhibition of nitric oxide (NO) synthesis, as the NO donor SNP could diminish this effect. In summary, JA effectively reduced Cd content in rice by modulating the cell wall’s capacity for Cd uptake, potentially through reducing the production of NO.

Sporothrix brasiliensis is one of the leading etiological agents of sporotrichosis, a cutaneous and subcutaneous mycosis worldwide distributed. This organism has been recently associated with epidemic outbreaks in Brazil. Despite the medical relevance of this species, little is known about its virulence factors, and most of the information on this subject is extrapolated from Sporothrix schenckii. Here, we generated S. brasiliensis mutants, where GP70 was silenced. In S. schenckii, this gene encodes a glycoprotein with adhesive properties required for virulence. The S. brasiliensis GP70 silencing led to an abnormal cellular phenotype, with smaller, round yeast-like cells that aggregate. Cell aggregation was disrupted with glucanase, suggesting this phenotype is linked to changes in the cell wall. The cell wall characterization confirmed changes in the structural polysaccharide β-1,3-glucan, which increased in quantity and exposure at the cell surface. This was accompanied by a reduction in protein content and N-linked glycans. Mutant strains with high GP70-silencing levels showed minimal levels of 3-carboxy-cis,cis-muconate cyclase activity, this glycoprotein's predicted enzyme function, and decreased ability to bind laminin and fibronectin. These phenotypical changes coincided with abnormal interaction with human peripheral blood mononuclear cells, where production of IL-1β, IL-17, and IL-22 was reduced and the strong dependence on cytokine stimulation via mannose receptor was lost. Phagocytosis by monocyte-derived macrophages was increased and virulence attenuated in a Galleria mellonella larvae. In conclusion, Gp70 is an abundant cell wall glycoprotein in S. brasiliensis that contributes to virulence and proper interaction with innate immnune cells.

AIM: This study aims to visually ascertain the differences in cell walls in Staphylococcus aureus which is sensitive and resistant to Vancomycin. Background. S. aureus is a common cause of infections that occur in hospitals. Over the past few decades, there has been an alarming increase in the prevalence of pathogens and strains resistant of S. aureus to antibiotics including Vancomycin. Resistance to vancomycin is carried by the vanA gene, characterized by thickening of the cell walls of S. aureus bacteria. METHODS: The research sample consisted of 19 isolates of S. aureus bacteria taken from diabetic ulcer swabs which were then subjected to the Minimum Inhibitory Concentration (MIC) test and visual examination of cell wall thickness by Transmission Microscope Electron (TEM). Result. The results of the study showed that 2 samples were Vancomycin-resistant Staphylococcus aureus (VRSA) based on the MIC test for the antibiotic Vancomycin with a MIC value of 32 μg/ML, which indicates that there was a strain that was resistant to the antibiotic Vancomycin because it had a MIC value more than of 16 μg/ML. There is a difference in the cell wall thickness of Vancomycin-sensitive Staphylococcus aureus (VSSA) and VRSA as optically discerned by the TEM. Based on the Independent T-test, observation of the cell walls of VSSA and VRSA bacteria showed a significant difference in thickness. CONCLUSION: This study concludes that there is a difference of the cell wall thickness of Vancomycin-sensitive Staphylococcus aureus and Vancomycin-resistant Staphylococcus aureus as optically discerned by the TEM.

In rice, cell-wall matrix polysaccharides contribute to salt–alkali tolerance. However, the mechanism by which cell-wall matrix polysaccharides and their biosynthetic genes regulate salt–alkali tolerance in rice remains unclear. To address this question, we report on the regulatory mechanism of salt–alkali tolerance of the 1,4-β-d-xylan synthase gene OsCSLD4 in the hemicellulose biosynthesis pathway. Mutant of OsCSLD4, nd1 and its wild-type were analyzed using comprehensive techniques and methods, including phenotyping, gene expression, comparative transcriptomic analysis, qPCR validation, and determination of physio-biochemical indices. We found that the salt–alkali tolerance of nd1 was lower than that of the wild type, and the expression of the OsCSLD4 gene was induced under salt–alkali stress. Comparative transcriptomic analysis revealed that the expression levels of genes involved in photosynthesis, carbohydrate, and cell wall matrix polysaccharide biosynthesis pathways in nd1 seedlings were downregulated compared to those in the wild type under salt–alkali stress. Accordingly, physio-biochemical analysis demonstrated that nd1 seedlings had reduced levels of chlorophyll, total soluble sugar, starch, and hemicellulose, coupled with a significant increase in malondialdehyde content under salt–alkali stress. In essence, the OsCSLD4 gene confers salt–alkali tolerance to rice by regulating the hemicellulose content to strengthen cell wall integrity and enhance intracellular physio-biochemical salt–alkali tolerance at the cellular level, thereby maintaining photosynthetic capacity and growth at the plant level. This study revealed that OsCSLD4 has potential value in molecular breeding for the development of salt-alkali-tolerant rice varieties.

Hemp (Cannabis sativa L.) is a versatile crop that produces cellulosic bast fibres used in textiles and biocomposites. Is also finds use in phytoremediation, being a good candidate for the cultivation on marginal lands, such as those contaminated by heavy metals (HMs). HMs like cadmium (Cd) and zinc (Zn) are known to affect plant growth and impair the biosynthesis of cellulose and lignin at the cell wall level. Since cellulose is the major component in the gelatinous layer of bast fibres, HMs can impact the structure of hemp fibres and, consequently, their mechanical properties. This study investigates how varying concentrations of Cd and Zn in the soil affect the bast fibres of hemp plantlets. The chosen model is the hypocotyl, as it is ideal for studying bast fibre development: it exhibits a temporal separation between the elongation and thickening phases within a short period of approximately three weeks. C. sativa plantlets were grown for 20 days, and the hypocotyls sampled to perform histochemical observations, gene expression analysis, as well as to quantify biomass yield and Cd/Zn accumulation. Hemp plantlets grown in soils with the three highest Zn concentrations were smaller than the control group, whereas no decrease in size was observed under elevated Cd concentrations. However, at the highest Cd concentration, the root system exhibited enhanced development, accompanied by a significant increase in dry weight across all the concentrations tested. The quantification of Cd and Zn showed that the roots were the main organs accumulating HMs. Cd at the two highest concentrations decreased significantly the lumen area of bast fibres and increased their cell wall thickness. Zn decreased significantly the lumen area, but it did not impact the thickness of the cell wall at the highest concentration. Cd also increased the number of secondary fibres. Immunohistochemistry highlighted a different pattern of crystalline cellulose distribution with a signal that was less homogeneous in the presence of Cd and Zn. Gene expression analysis revealed changes in transcripts encoding cellulose synthases, fasciclin-like arabinogalactan proteins, class III peroxidases. The results obtained shed light on the molecular response and bast fibre histological changes occurring in young hemp plants exposed to Cd and Zn.

Due to the continuous production of industrial wastes and the excessive use of chemical fertilizers and pesticides, severe cadmium (Cd) pollution in soil has occurred globally. This study investigated the impacts of incorporating zinc oxide nanoparticles (ZnONPs) into hydroponically grown lettuce (Lactuca sativa) under cadmium stress conditions, to seek effective methods to minimize Cd buildup in green leafy vegetables. The results showed that 1 mg/L of Cd significantly inhibited lettuce growth, decreasing in leaves (29 %) and roots (33 %) biomass. However, when lettuce was exposed to 2.5 mg/L ZnONPs under cadmium stress, the growth, chlorophyll content, net photosynthetic rate (Pn), stomatal conductance (Gs), actual photochemical efficiency of PSII (φPSII), and activity of key enzymes in photosynthesis were all significantly enhanced. Furthermore, ZnONPs significantly decreased the accumulation of Cd in lettuce leaves (36 %) and roots (13 %). They altered the subcellular distribution and chemical morphology of Cd in lettuce by modifying the composition of cell walls (such as pectin content) and the levels of phenolic compounds, resulting in a reduction of 27 % in Cd translocation from roots to leaves. RNA sequencing yielded 45.9 × 107 and 53.4 × 107 clean reads from plant leaves and roots in control (T0), Cd (T1), Cd+ZnONPs (T2), and ZnONPs (T3) treatment groups respectively, and 3614 and 1873 differentially expressed genes (DEGs) were identified. Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analysis identified photosynthesis, carbon fixation, and phenylpropanoid metabolism as the main causes of ZnONPs-mediated alleviation of Cd stress in lettuce. Specifically, the DEGs identified included 12 associated with photosystem I, 13 with photosystem II and 23 DEGs with the carbon fixation pathway of photosynthesis. Additionally, DEGs related to phenylalanine ammonia-lyase, caffeoyl CoA 3-O-methyltransferase, peroxidase, 4-coumarate-CoA ligase, hydroxycinnamoyl transferase, and cytochrome P450 proteins were also identified. Therefore, further research is recommended to elucidate the molecular mechanisms by which ZnONPs reduce Cd absorption in lettuce through phenolic acid components in the phenylpropanoid metabolism pathway. Overall, treatments with ZnONPs are recommended to effectively reduce Cd accumulation in the edible portion of lettuce.

The application of metal-based nanoparticles in inhibiting plant pathogenic bacteria and fungi has gained significant attention in recent years. several nanoparticles, including silver (Ag), titanium dioxide (TiO2), magnesium oxide (MgO), copper (Cu), and zinc oxide (ZnO), can generate reactive oxygen species (ROS) when exposed to light. The oxidative damage inflicted by ROS can disrupt the cellular structures and metabolic processes of pathogens, leading to their inactivation and inhibition. However, it is crucial to consider the potential environmental and health impacts of nanoparticle use. The safe and responsible use of nanoparticles and their potential risks should be thoroughly evaluated to ensure sustainable and effective plant disease management practices.

ABSTRACT: Objectives: This study aimed to identify the resistance mechanisms to micafungin and fluconazole in a clinical isolate of Candida glabrata. Methods: The isolate was whole-genome sequenced to identify amino acid changes in key proteins involved in antifungal resistance, and the isolate was further characterised by pathogenicity-related phenotypic assays that supported the sequencing results. Results: Amino acid substitutions were detected in 8 of 17 protein candidates. Many of these substitutions were novel, including in CHS3, CHS3B, and KRE5, which are involved in the development of micafungin resistance. Regarding fluconazole resistance, overexpression of efflux pumps was observed. Our isolate did not exhibit an increased virulence potential compared with the control strain; however, a significant increase in chitin content and potential to resist the cell surface disruptant sodium dodecyl sulphate was observed. Conclusions: This clinical Candida glabrata isolate experienced a change in cell wall architecture, which correlates with the development of micafungin resistance.

The cell wall serves as the primary barrier against the entry of heavy metal ions into cells. However, excessive accumulation of heavy metals within plants can lead to alterations in the spatial structure and physical properties of the cell wall, thereby affecting the capacity of plants to capture heavy metals. Proline (Pro) is involved in the synthesis of the cell wall, modulating the stability and integrity of its structure. Extensins, core proteins that maintain the cell wall structure, are proline/hydroxyproline-rich glycoproteins that contain the characteristic sequence Ser-[Pro]3–5. They act as intermediates in the regulation of biological processes such as cell wall synthesis, assembly, and signal transduction, typically forming a network structure of cell wall proteins through cross-linking with pectin. This network is essential for the self-assembly expansion of the plant cell wall and plays an indispensable role in cell wall stress signal transduction through its interaction with intracellular signalling molecules. However, the mechanisms by which Pro affects the synthesis of cell wall structural proteins, cell wall assembly, and the sensing of cell wall stress under heavy metal stress remain unclear. This review, from the perspectives of biochemistry and molecular biology, comprehensively elaborates on the impact of Pro and Pro-rich proteins on the structure and function of the cell wall. These findings emphasize the mechanism by which Pro enhances the ability of the cell wall to capture heavy metals, providing new research ideas for the use of genetic engineering to manipulate cell wall synthesis and repair, thereby reducing the phytotoxicity of heavy metals.

The genus Distichlis comprises halophytic perennial C4 grasses which grow in very extreme conditions. It is distributed throughout almost the entire American continent. Despite these interesting characteristics, studies on these plants are relatively scarce, and their ecological and productive value deserves to be further explored. In this work, nutritional aspects, and composition of the cell walls of the aerial part (leaves and shoots) of D. laxiflora Hack were studied. Their changes over four samplings in different seasons, in two nearby sites: a halophytic meadow (H), and a mesophytic meadow (M), were analyzed. Photosynthetic efficiency and K/Na ratio were determined as stress indicators. Plants of sites H and M have similar cell wall content except for spring when plants from site H show lower values. Also, the spring samples present a markedly higher in vitro digestibility for site H. In agreement, samples from site H contain lower amounts of glucuronoarabinoxylans and β-glucans. The protein content is lower in site H, except for spring, and with a maximum in summer for site M. This work shows some changes in the cell walls of D. laxiflora in response to salinity, and these changes influence the digestibility of this material. Spring, coinciding with the regrowth cycle of this plant and with the worst stress indicators, is the season when plants of the halophytic site show the highest nutritional quality for grazing cattle.

The interactions between bacteria and microalgae play pivotal roles in resource allocation, biomass accumulation, nutrient recycling, and species succession in aquatic systems, offering ample opportunities to solve several social problems. The escalating threat of harmful algal blooms (HABs) in the aquatic environment and the lack of cheap and eco-friendly algal-biomass processing methods have been among the main problems, demanding efficient and sustainable solutions. In light of this, the application of algicidal bacteria to control HABs and enhance algal biomass processing has been promoted in the past few decades as potentially suitable mechanisms to solve those problems. Hence, this comprehensive review aims to explore the diverse interaction modes between bacteria and microalgae, ranging from synergistic to antagonistic, and presents up-to-date information and in-depth analysis of their potential biotechnological applications, particularly in controlling HABs and enhancing microalgal biomass processing. For instance, several studies revealed that algicidal bacteria can effectively inhibit the growth of Microcystis aeruginosa, a notorious freshwater HAB species, with an antialgal efficiency of 24.87 %–98.8 %. The review begins with an overview of the mechanisms behind algae-bacteria interactions, including the environmental factors influencing these dynamics and their broader implications for aquatic ecosystems. It then provides a detailed analysis of the role of algicidal bacteria in controlling harmful algal blooms, as well as their role in bioflocculation and the pretreatment of microalgal biomass. Additionally, the review identifies and discusses the constraints and challenges in the biotechnological application of these interactions. By exploring the strategic use of algicidal bacteria, this review not only underscores their importance in maintaining aquatic environmental health but also in enhancing biomass processing efficiency. It offers valuable insights into future research avenues and the potential scalability of these applications, both in situ and at an industrial level.

Soil Cd pollution is a significant environmental issue faced by contemporary society. Kentucky bluegrass is considered a potential phytoremediation species, as some varieties have excellent cadmium (Cd) tolerance. However, the mechanisms of Cd accumulation and transportation in Kentucky bluegrass are still not fully understood. The Cd-tolerant Kentucky bluegrass cultivar ‘Midnight’ (M) exhibits lower Cd translocation efficiency and a higher leaf Cd concentration compared to the Cd-sensitive cultivar ‘Rugby II’ (R). We hypothesized that Cd translocation from roots to shoots in cultivar M is hindered by the endodermal barriers and cell wall polysaccharides; hence, we conducted Cd distribution, cytological observation, cell wall component, and transcriptomic analyses under Cd stress conditions using the M and R cultivars. Cd stress resulted in the thickening of the endodermis and increased synthesis of cell wall polysaccharides in both the M and R cultivars. Endodermis development restricted the radical transport of Cd from the root cortex to the stele, while the accumulation of cell wall polysaccharides promoted the binding of Cd to the cell wall. These changes further inhibited the long-distance translocation of Cd from the roots to the aerial parts. Furthermore, the M cultivar exhibited limited long-distance Cd translocation efficiency compared to the R cultivar, which was attributed to the enhanced development of endodermal barriers and increased Cd binding by cell wall polysaccharides. This study provides valuable insights for screening high Cd transport efficiency in Kentucky bluegrass based on anatomical structure and genetic modification.

The morphological development of rice (Oryza sativa L.) leaves is closely related to plant architecture, physiological activities, and resistance. However, it is unclear whether there is a co-regulatory relationship between the morphological development of leaves and adaptation to drought environment. In this study, a drought-sensitive, roll-enhanced, and narrow-leaf mutant (renl1) was induced from a semi-rolled leaf mutant (srl1) by ethyl methane sulfonate (EMS), which was obtained from Nipponbare (NPB) through EMS. Map-based cloning and functional validation showed that RENL1 encodes a cellulose synthase, allelic to NRL1/OsCLSD4. The RENL1 mutation resulted in reduced vascular bundles, vesicular cells, cellulose, and hemicellulose contents in cell walls, diminishing the water-holding capacity of leaves. In addition, the root system of the renl1 mutant was poorly developed and its ability to scavenge reactive oxygen species (ROS) was decreased, leading to an increase in ROS after drought stress. Meanwhile, genetic results showed that RENL1 and SRL1 synergistically regulated cell wall components. Our results revealed a theoretical basis for further elucidating the molecular regulation mechanism of cellulose on rice drought tolerance, and provided a new genetic resource for enhancing the synergistic regulation network of plant type and stress resistance, thereby realizing simultaneous improvement of multiple traits in rice.

The increased awareness of environmental problems has shifted the attention from synthetic polymer porous materials to natural plant porous materials like bamboo parenchyma tissue to develop functional materials. However, the neglect of the inherent structure and property of plant porous materials leads to insufficient development and utilization of their natural advantages. Here, we investigated the fine structure and mechanisms of bamboo parenchyma tissue, which has multiple high-quality properties like energy-absorbing and toughening, to provide a basis for their wide utilization in porous materials. Results showed that bamboo parenchyma tissue was a foam-like porous material with sufficient strength, high porosity and low density. It was composed of cell walls and four types of three-dimensional polyhedral pores converging in space. The total natural porosity was up to 78.80%. The cell walls exhibited a three-zone strength distribution with an average solid cell wall strength of 75.84 MPa, due to their cocoon-like closed microfibrils patterns, chemical compositions and pits characteristics. The high porosity and weakening of transition zone and cell end wall helped to absorb energy. This study provides ideas for the application of bamboo parenchyma tissue in cushioning energy-absorbing foam materials and porous material templates and for the biomimetic design of environmentally friendly porous materials.

Ultrasound processing is an emerging green technology that has the potential for wider application in the food processing industry. While the effects of ultrasonication on isolated macromolecules such as protein and starch have been reported, the effects of physical barriers on sonication on these macro-molecules, for example inside whole seed, tissue or cotyledon cells, have mostly been overlooked. Intact chickpea cells were subjected to sonication with different ultrasound processing times, and the effects of sonication on the starch and protein structure and digestibility were studied. The digestibility of these macronutrients significantly increased with the extension of processing time, which, however was not due to the molecular degradation of starch or protein but related to damage to cell wall macro-structure with increasing sonication time, leading to enhanced enzyme accessibility. Through this study, it is demonstrated that ultrasound processing has least effect on whole food structure, for example, whole seeds but can modulate the nutrient bioavailability without changing the properties of the macronutrients in seed fractions e.g. intact cells, offering new scientific knowledge on effect of ultrasound in whole foods at various length scales.

The plant cell wall, a vital component in providing structural integrity and facilitating growth, comprises cellulose microfibrils among its major constituents. This study employed Atomic Force Microscopy (AFM) to investigate the intricate relationship between genetic mutation, cellulose microfibril organization, nanomechanical properties of cellulose microfibrils and plant growth. Focusing on the Arabidopsis thaliana wild type (WT) and ixr1–2 mutant population (known for resistance to herbicide ISOXABEN), we utilized AFM to scrutinize cellulose microfibrils on the newly synthesized cell wall in 5-day-old dark-grown hypocotyls. Our macroscopic analysis revealed significant differences in plant growth, prompting a detailed examination at the nanoscale using AFM to discover if the macroscopic disparity between these two populations gets translated in structural details, orientation, and mechanical properties of cellulose microfibrils at the nanoscale too. AFM analysis highlighted distinct organizational disparities in cellulose microfibrils between the WT and mutant population. Our results revealed that the WT manifests a more aligned and oriented microfibril structure in contrast to the mutant population that shows significantly less aligned cellulose microfibrils in the plant growth direction. Also, the WT and mutant population demonstrate nuanced differences in height, width, roughness, deformation, and stiffness. The observed nanoscale alterations in microfibril structure and nano-mechanical properties contribute to an improved understanding of the intricate dynamics governing plant cell wall structure and its pivotal role in growth and development.

Melatonin (MT) participates in plants' responses in plants’ response to cadmium (Cd) tolerance, although its work model remains elusive. Here, the function of MT in adjusting Cd accumulation in Gossypium hirsutum (CCRI12) was investigated. In this research we observed that exogenous 50 μM MT significantly reduced the Cd accumulation under 100 μМ Cd stress for 7 days of treatment in cotton seedlings. Cd markedly induced the ROS (H2O2, O2-) accumulation and elevated the expression of transporters for Cd uptake and translocation. After application of MT reduced ROS and MDA accumulation in response to high induction of antioxidant defense system; the genes encoding superoxide dismutase (GhSOD), catalase (GhCAT), and peroxidase (GhPOD), ascorbate peroxidase (GhAPX), and glutathione S-transferase (GhGST) were significantly upregulated accompanied by their level of content. Furthermore, MT down-regulated transporters for Cd uptake include Natural Resistance-Associated Macrophage Protein 1 (GhNRAMP3), Zinc/Iron-regulated transporter-like protein (GhZIP1/4/6), Heavy Metal ATPase gene (GhHMA2), and ATP-binding Cassette sub family C (GhABCC3/2). Exogenous application of MT raised the hemicelluloses, cellulose and pectin content accompanied by their expression levels, xyloglucan endotransglucosylase/hydrolase (GhXTH28/6/9/B), cellulose synthase like (GhCSLG1/2) and COBRA-like (GhCOBL4), pectin acetylesterases (GhPAE8/7), pectin methylesterases (GhPME31) which in turn increased the cell wall's binding capacity to Cd.

Desiccation tolerance has emerged as a potential strategy for crop improvement. However, the application of desiccation tolerance in crops, particularly rice, has been challenging and limited. Studies in angiosperms suggest that desiccation in vegetative tissues shares a common set of genes, developed convergently by modifying shared pathways associated with seed desiccation. The drought-tolerant Oryza sativa ssp. indica cv MR303 has demonstrated the capability to withstand desiccation state for a short period of time. Using this variety, we aim to investigate the factors that limit rice plants from achieving desiccation tolerance. The irreversibility of the cell wall emerges as a primary factor hindering rice plants from acquiring desiccation tolerance. Analysis of cell wall composition and transcriptomic data reveals an accumulation of secondary cell wall components and the expression of cell wall-related genes involved in secondary wall formation and modification, suggesting that these factors could be underlying causes for the irreversibility of the cell wall. Such factors contribute to the rigidity and stiffness of the cell wall, leading to its irreversibility during the rehydration process. This, in turn, impedes the recovery of rice after dehydration.

Host recognition of the pathogen-associated molecular pattern (PAMP), β-1,3-glucan, plays a major role in antifungal immunity. β-1,3-glucan is an essential component of the inner cell wall of the opportunistic pathogen Candida albicans. Most β-1,3-glucan is shielded by the outer cell wall layer of mannan fibrils, but some can become exposed at the cell surface. In response to host signals such as lactate, C. albicans shaves the exposed β-1,3-glucan from its cell surface, thereby reducing the ability of innate immune cells to recognise and kill the fungus. We have used sets of barcoded xog1 and eng1 mutants to compare the impacts of the secreted β-glucanases Xog1 and Eng1 upon C. albicans in vitro and in vivo. Flow cytometry of Fc-dectin-1-stained strains revealed that Eng1 plays the greater role in lactate-induced β-1,3-glucan masking. Transmission electron microscopy and stress assays showed that neither Eng1 nor Xog1 are essential for cell wall maintenance, but the inactivation of either enzyme compromised fungal adhesion to gut and vaginal epithelial cells. Competitive barcode sequencing suggested that neither Eng1 nor Xog1 strongly influence C. albicans fitness during systemic infection or vaginal colonisation in mice. However, the deletion of XOG1 enhanced C. albicans fitness during gut colonisation. We conclude that both Eng1 and Xog1 exert subtle effects on the C. albicans cell surface that influence fungal adhesion to host cells and that affect fungal colonisation in certain host niches.

Pattern-Triggered Immunity (PTI) in plants is activated upon recognition by Pattern Recognition Receptors (PRRs) of Damage- and Microbe-Associated Molecular Patterns (DAMPs and MAMPs) from plants or microorganisms, respectively. An increasing number of identified DAMPs/MAMPs are carbohydrates from plant cell walls and microbial extracellular layers, which are perceived by plant PRRs, such as LysM and Leucine Rich Repeat-Malectin (LRR-MAL) receptor kinases (RKs). LysM-RKs (e.g. CERK1, LYK4 and LYK5) are needed for recognition of fungal MAMP chitohexaose (β-1,4-D-(GlcNAc)6, CHI6), whereas IGP1/CORK1, IGP3 and IGP4 LRR-MAL RKs are required for perception of β-glucans, like cellotriose (β-1,4-D-(Glc)3, CEL3) and mixed-linked glucans. We have explored the diversity of carbohydrates perceived by Arabidopsis thaliana seedlings by determining PTI responses upon treatment with different oligosaccharides and polysaccharides. These analyses revealed that plant oligosaccharides from xylans [β-1,4-D-(xylose)4 (XYL4)], glucuronoxylans and α-1,4-glucans, and polysaccharides from plants and seaweeds activate PTI. Cross-elicitation experiments of XYL4 with other glycans showed that the mechanism of recognition of XYL4 and the DAMP 33-α-L-arabinofuranosyl-xylotetraose (XA3XX) shares some features with that of CEL3 but differs from that of CHI6. Notably, XYL4 and XA3XX perception is impaired in igp1/cork1, igp3 and igp4 mutants, and almost not affected in cerk1 lyk4 lyk5 triple mutant. XYL4 perception is conserved in different plant species since XYL4 pre-treatment triggers enhanced disease resistance in tomato to Pseudomonas syringae pv tomato DC3000 and PTI responses in wheat. These results expand the number of glycans triggering plant immunity and support IGP1/CORK1, IGP3 and IGP4 relevance in Arabidopsis thaliana glycans perception and PTI activation. Significance Statement: The characterization of plant immune mechanisms involved in the perception of carbohydrate-based structures recognized as DAMPs/MAMPs is needed to further understand plant disease resistance modulation. We show here that IGP1/CORK1, IGP3 and IGP4 LRR-MAL RKs are required for the perception of carbohydrate-based DAMPs β-1,4-D-(xylose)4 (XYL4) and 33-α-L-arabinofuranosyl-xylotetraose (XA3XX), further expanding the function of these LRR-MAL RKs in plant glycan perception and immune activation.

Every fungal cell is encapsulated in a cell wall, essential for cell viability, morphogenesis, and pathogenesis. Most knowledge of the cell wall composition in fungi has focused on ascomycetes, especially human pathogens, but considerably less is known about early divergent fungal groups, such as species in the Zoopagomycota and Mucoromycota phyla. To shed light on evolutionary changes in the fungal cell wall, we studied the monosaccharide composition of the cell wall of 18 species including early diverging fungi and species in the Basidiomycota and Ascomycota phyla with a focus on those with pathogenic lifestyles and interactions with plants. Our data revealed that chitin is the most characteristic component of the fungal cell wall, and was found to be in a higher proportion in the early divergent groups. The Mucoromycota species possess few glucans, but instead have other monosaccharides such as fucose and glucuronic acid that are almost exclusively found in their cell walls. Additionally, we observed that hexoses (glucose, mannose and galactose) accumulate in much higher proportions in species belonging to Dikarya. Our data demonstrate a clear relationship between phylogenetic position and fungal cell wall carbohydrate composition and lay the foundation for a better understanding of their evolution and their role in plant interactions.

Fruit development and ripening is a complex procedure (Malus×domestica Borkh.) and can be caused by various factors such as cell structure, cell wall components, and cell wall hydrolytic enzymes. In our study, we focused on the variations in fruit firmness, cell wall morphology and components, the activity of cell wall hydrolytic enzymes and the expression patterns of associated genes during fruit development in two different types of apple cultivars, the hard-crisp cultivar and the loose-crisp cultivar. In this paper, the aim was to find out the causes of the texture variations between the different type cultivars. Cell wall materials (CWMs), hemicellulose and cellulose content were strongly associated with variations in fruit firmness during the fruit development. The content of water soluble pectin (WSP) and chelator soluble pectin (CSP) gradually increased, while the content of ionic soluble pectin (ISP) showed inconsistent trends in the four cultivars. The activities of polygalacturonase (PG), β-galactosidase (β-gal), cellulase (CEL), and pectate lyase (PL) gradually increased in four cultivars. And the activities of PG, β-gal, and CEL were higher in ‘Fuji’ and ‘Honeycrisp’ fruit with the fruit development, while the activity of PL of ‘Fuji’ and ‘Honeycrisp’ was lower than that of ‘ENVY’ and ‘Modi’. Both four cultivars of fruit cells progressively became bigger as the fruit expanded, with looser cell arrangements and larger cell gaps. According to the qRT-PCR, the relative expression levels of MdACO and Mdβ-gal were notably enhanced. Our study showed that there were large differences in the content of ISP and hemicellulose, the activity of PL and the relative expression of Mdβ-gal between two different types of apple cultivars, and these differences might be responsible for the variations in the texture of the four cultivars.

Introduction: Postharvest textural changes in fruit are mainly divided into softening and lignification. Loquat fruit could have severe lignification with increased firmness during postharvest storage. Pectin is mainly associated with the postharvest softening of fruit, but some studies also found that pectin could be involved in strengthening the mechanical properties of the plant. Objectives: This study focused on characterizing the dynamics of pectin and its complexation in the cell wall of lignified loquat fruit during postharvest storage, and how these changes could influence fruit firmness. Methods: The homogalacturonan (HG) pectin in the cell wall of loquat fruit was identified using monoclonal antibodies. An oligogalacturonide (OG) probe was used to label the egg-box structure formed by Ca2+ cross-linking with low-methylesterified HG. An exogenous injection was used to verify the role of egg-box structures in the firmness increase in loquat fruit. Results: The JIM5 antibody revealed that low-methylesterified HG accumulated in the tricellular junctions and middle lamella of loquat fruit that had severe lignification symptoms. The pectin methylesterase (PME) activity increased during the early stages of storage at 0 °C, and the calcium-pectate content and flesh firmness constantly increased during storage. The OG probe demonstrated the accumulation of egg-box structures at the cellular level. The exogenous injection of PME and Ca2+ into the loquat flesh led to an increase in firmness with more low-methylesterified HG and egg-box structure signals. Conclusion: PME-mediated demethylesterification generated large amounts of low-methylesterified HG in the cell wall. This low-methylesterified HG further cross-linked with Ca2+ to form egg-box structures. The pectin-involved complexations then contributed to the increased firmness in loquat fruit. Overall, besides being involved in fruit softening, pectin could also be involved in strengthening the mechanical properties of postharvest fruit. This study provides new ideas for obtaining a better texture of postharvest loquat fruits based on pectin regulation.

Upland cotton (Gossypium hirsutum L.) is the most important natural textile fiber crop worldwide. Plant height (PH) is a significant component of plant architecture, strongly influencing crop cultivation patterns, overall yield, and economic coefficient. However, cotton genes regulating plant height have not been fully identified. Previously, an HD-Zip gene (GhHB12) was isolated and characterized in cotton, which regulates the abiotic and biotic stress responses and the growth and development processes. In this study, we showed that GhHB12 was induced by auxin. Moreover, overexpression of GhHB12 induces the expression of HY5, ATH1, and HAT4, represses the spatial-temporal distribution, polar transport, and signaling of auxin, alters the expression of genes involved in cell wall expansion, and restrains the plant height in cotton. These results suggest a role of GhHB12 in regulating cotton plant height, which could be achieved by affecting the auxin signaling and cell wall expansion.

Isolates of Rhizoctonia solani (AG-3 PT, AG-4 HG-I, AG-4 HG-II) and one binucleate Rhizoctonia sp. (BNR) belonging to AG-Bb were investigated for pathogenicity on tomato cultivar Mobil. The BNR isolate revealed the lowest virulence and it was used as biocontrol agent against R. solani AG-4 HG-II, which showed the highest virulence on tomato. Inoculation of tomato plants with the hypovirulent BNR isolate reduced the disease symptoms of R. solani and induced resistance. Resistance induction was observed not only on the plants simultaneously inoculated with BNR and R. solani, but also when the plants were inoculated by the BNR and R. solani with time intervals. The peroxidase (POX), superoxide dismutase (SOD) and catalase (CAT) activities and expression levels of the corresponding genes in tomato plants increased after R. solani or BNR inoculation. The highest level of antioxidant activities and expression of their genes, lignin and callose formation were observed in the plants inoculated with the BNR and R. solani, simultaneously. The BNR inoculation reduced H2O2 accumulation. The highest level of priming was observed for the POX among other antioxidants tested via application of the BNR. Treatment with potassium cyanide (as a POX inhibitor) reduced basal resistance and BNR-induced resistance (BNR-IR) via reduction of lignification and callose deposition in tomato plants. These findings demonstrated the role of antioxidant enzymes, mainly the POX, in both basal resistance and BNR-IR. Therefore, redox state and antioxidants are involved in cell wall strengthening via lignin and callose formation, as important defense components which decrease the pathogen progress in plant tissues.

Pea cell walls have been shown to encapsulate nutrients inside cells, thereby limiting their hydrolysis by digestive enzymes. However, it is unknown how the cell wall performs this barrier function. In particular, this could be due to the presence of specific polysaccharides or, most probably, the organisation of the components within the cell wall. This study aimed to investigate how cell walls prevented protein hydrolysis. To address this objective, isolated cells were obtained using different treatments thought to affect cell walls differently (incubations in water, salt or EDTA solutions) and digested in vitro using a three-phase (oral, gastric and intestinal) model. Purified polysaccharides (cellulose, rhamnogalacturonan I and xyloglucan) and solutions obtained from the incubation of pea fibres and flour were also used in our digestion experiments. We found that protein bioaccessibility (here defined as the amount of protein released from the pea cells) and hydrolysis was lower after the gastric phase for the isolated cells prepared with the salt solution compared to the other treatments. Regardless of the treatment, between 47% and 93% of proteins were released from the cells (bioaccessible) and hydrolysed, respectively. Therefore, after prolonged incubation time proteases seem to be able to penetrate the cells during digestion. In terms of purified polysaccharides, rhamnogalacturonan I had the greatest effect on protein hydrolysis. Incubation solutions made from the pea fibres reduced proteolysis to a greater extent than the pea flour. The present study showed that pea cell walls delay protein digestion mainly via its structural organisation within the cell wall, with purified polysaccharides having a more limited effect.

Phosphorus (P) starvation in rice facilitates the reutilization of root cell wall P by enhancing the pectin content. NaCl modulates pectin content, however, it is still unknown whether NaCl is also involved in the process of pectin regulated cell wall P remobilization in rice under P starved conditions. In this study, we found that 10 mmol/L NaCl increased the shoot and root biomasses under P deficiency to a remarkable extent, in company with the elevated shoot and root soluble P contents in rice. Further analysis indicated that exogenous NaCl enhanced the root cell wall P mobilization by increasing the pectin methylesterase activity and uronic acid content in pectin suggesting the involvement of NaCl in the process of cell wall P reutilization in P starved rice roots. Additionally, exogenous NaCl up-regulated the expression of P transporter OsPT6, which was induced by P deficiency, suggesting that NaCl also facilitated the P translocation prominently from root to shoot in P starved rice. Moreover, exogenous abscisic acid (ABA) can reverse the NaCl-mediated mitigation under P deficiency, indicating the involvement of ABA in the NaCl regulated root cell wall P reutilization. Taken together, our results demonstrated that NaCl can activate the reutilization of root cell wall P in P starved rice, which is dependent on the ABA accumulation pathway.

Root hairs are cells from the root epidermis that grow as long tubular bulges perpendicular to the root. They can grow in a variety of mechanical or chemical environments. Their mechanical properties are mainly due to their stiff cell wall which also constitutes a physical barrier between the cell and its environment. Thus, it is essential to be able to quantify the cell wall mechanical properties and their adaptation to environmental cues. Here, we present a technique we developed to measure the Young’s (elastic) modulus of the root hair cell wall. In essence, using custom-made glass microplates as cantilevers of calibrated stiffness, we are able to measure the force necessary to bend a single living root hair. From these experiments one can determine the stiffness and Young’s modulus of the root hair cell wall.

EXTENSINS (EXTs) are an abundant and yet enigmatic class of cell wall proteins that are found across multicellular plant lineages, from Bryophytes to Angiosperms. They have been shown to be integrated within the cell wall matrix, and are proposed to play key roles in the dynamic regulation of cell-wall properties. Consistent with this, EXTs are thought to be important for plant growth and development. However, like many other classes of cell wall proteins, EXTs are biochemically complex, highly diverse, and are encoded by multiple genes, making in-depth functional characterization a challenging undertaking. Here we will provide an overview of current knowledge of the biochemistry and properties of EXTs, and of the tools that have been deployed to study their biological functions in plants.

The cell wall fulfils several functions in the biology of fungi. For instance, it provides mechanical strength, interacts with the (a)biotic environment, and acts as a molecular sieve. Recently, it was shown that proteins and β-glucans in the cell wall of Schizophyllum commune bind Cu2+. We here show that the cell wall of this mushroom forming fungus also binds other (micro-)nutrients. Ca2+, Mg2+, Mn2+, NO3–, PO43-, and SO42- bound at levels > 1 mg per gram dry weight cell wall, while binding of BO3-, Cu2+, Zn2+ and MoO42- was lower. Sorption of Ca2+, Mn2+, Zn2+ and PO43- was promoted at alkaline pH. These compounds as well as BO33-, Cu2+, Mg2+, NO3–, and SO42- that had bound at pH 4, 6, or 8 could be released from the cell wall at pH 4 with a maximum efficiency of 46–93 %. Solid-state NMR spectroscopy showed that the metals had the same binding sites as Cu2+ when a low concentration of this ion is used. Moreover, data indicate that anions bind to the cell wall as well as to the metal ions. Together, it is shown that the cell wall of S. commune binds various (micro-)nutrients and that this binding is higher than the uptake by hyphae. The binding to the cell wall may be used as a storage mechanism or may reduce availability of these molecules to competitors or prevent toxic influx in the cytoplasm.

Candida auris is a multi-drug resistant human fungal pathogen that has become a global threat to human health due to its drug resistant phenotype, persistence in the hospital environment and propensity for patient to patient spread. Isolates display variable aggregation that may affect the relative virulence of strains. Therefore, dissection of this phenotype has gained substantial interest in recent years. We studied eight clinical isolates from four different clades (I-IV); four of which had a strongly aggregating phenotype and four of which did not. Genome analysis identified polymorphisms associated with loss of cell surface proteins were enriched in weakly-aggregating strains. Additionally, we identified down-regulation of chitin synthase genes involved in the synthesis of the chitinous septum. Characterisation of the cells revealed no ultrastructural defects in cytokinesis or cell separation in aggregating isolates. Strongly and weakly aggregating strains did not differ in net surface charge or in cell surface hydrophobicity. The capacity for aggregation and for adhesion to polystyrene microspheres were also not correlated. However, aggregation and extracellular matrix formation were all increased at higher growth temperatures, and treatment with the amyloid protein inhibitor Thioflavin-T markedly attenuated aggregation. Genome analysis further indicated strain specific differences in the genome content of GPI-anchored proteins including those encoding genes with the potential to form amyloid proteins. Collectively our data suggests that aggregation is a complex strain and temperature dependent phenomenon that may be linked in part to the ability to form extracellular matrix and cell surface amyloids.

The tea plant accumulates elevated levels of fluoride (F) from environmental sources. Drinking tea containing high F levels poses a potential threat to human health. Selenium (Se) was applied by foliar spray to investigate its effects on F accumulation and physiology in tea plant. Foliar application of different forms of Se, i.e., Na2SeO3, Kappa-selenocarrageenan, Selenomethionine and Nanoselenium, reduced F content in tea leaves by 10.17 %−44.28 %, 16.12 %−35.41 %, 22.19 %−45.99 % and 22.24 %−43.82 %, respectively. Foliar spraying Se could increase F accumulation in pectin through increasing pectin content and pectin demethylesterification to bind more F in the cell wall, which decreased the proportion of water-soluble fluoride in tea leaves. Application of Se significantly decreased the contents of chromium (39.6 %−72.0 %), cadmium (48.3 %−84.4 %), lead (2.2 %−44.4 %) and copper (14.1 %−44.6 %) in tea leaves. Foliar spraying various forms of Se dramatically increased the Se content and was efficiently transformed into organic Se accounting for more than 80 % in tea leaves. All Se compounds increased peroxidase activity by 3.3 %−35.5 % and catalase activity by 2.6 %−99.4 %, reduced malondialdehyde content by 5.6 %−37.1 %, and increased the contents of chlorophyll by 0.65 %−31.8 %, carotenoids by 0.24 %−27.1 %, total catechins by 1.6 %−21.0 %, EGCG by 4.4 %−17.6 % and caffeine by 9.1 %−28.6 %. These results indicated that Se application could be served as a potential efficient and safe strategy diminishing the concentration of F in tea leaves.

In highly intensive greenhouse vegetable production, soil acidification was caused by excessive fertilization, increasing cadmium (Cd) concentrations in the vegetables, which bears environmental hazards and is a negative influence on vegetables and humans. Transglutaminases (TGases), a central mediator for certain physiological effects of polyamines (PAs) in the plant kingdom, play important roles in plant development and stress response. Despite increased research on the crucial role of TGase in protecting against environmental stresses, relatively little is known about the mechanisms of Cd tolerance. In this study, we found, TGase activity and transcript level, which was upregulated by Cd, and TGase-induced Cd tolerance related to endogenous bound PAs increase and formation of nitric oxide (NO). Plant growth of tgase mutants was hypersensitive to Cd, chemical complementation by putrescine, sodium nitroprusside (SNP, nitric oxide donor) or gain of function TGase experiments restore Cd tolerance. α-diflouromethylornithine (DFMO, a selective ODC inhibitor) and 2–4-carboxyphenyl-4,4,5,5-tetramethylimidazoline-1-oxyl-3-oxide (cPTIO, NO scavenger), were respectively found declined drastically endogenous bound PA and NO content in TGase overexpression plants. Likewise, we reported that TGase interacted with polyamine uptake protein 3 (Put3), and the silencing of Put3 largely reduced TGase-induced Cd tolerance and bound PAs formation. This salvage strategy depends on TGase-regulated synthesis of bound PAs and NO that is able to positively increase the concentration of thiol and phytochelatins, elevate Cd in the cell wall, as well as induce the levels of expression Cd uptake and transport genes. Collectively, these findings indicate that TGase-mediated enhanced levels of bound PA and NO acts as a vital mechanism to protect the plant from Cd-caused toxicity.

Large areas of soil in southern China are contaminated with cadmium (Cd) and are deficient in boron (B). Previously, we suggested that B supplementation could reduce Cd accumulation in hot peppers (Capsicum annuum L.); however, the physiological mechanisms underlying this reduction remain unclear. In this study, the uptake and translocation of Cd in hot pepper plants were investigated using hydroponic experiments with different B and Cd treatments. A pot experiment was performed to verify whether B decreased the Cd concentration in hot peppers by minimizing the Cd translocation rate. The results of the dose- and time-dependent experiments showed that B supplementation reduced root Cd uptake and root-to-shoot Cd translocation. Additionally, B supplementation increased the root length, diameter, volume, surface area, and number of root forks and tips, as well as improving the relative absorbance of carboxyl groups under Cd exposure, leading to enhanced Cd fixation in the cell walls of the roots. As a result, the fruit Cd concentration decreased because B inhibited Cd translocation from the roots. Overall, the results demonstrate that B supplementation can reduce Cd accumulation in hot peppers by promoting normal root growth and development and by limiting the uptake and translocation of Cd.

Cadmium (Cd) accumulation in crops causes potential risks to human health. Microbial extracellular polymeric substances (EPS) are a complex mixture of biopolymers that can bind various heavy metals. The present work examined the alleviating effects of EPS on Cd toxicity in rice and its detoxification mechanism. The 100 μM Cd stress hampered the overall plant growth and development, damaged the ultrastructures of both leaf and root cells, and caused severe lipid peroxidation in rice plants. However, applying EPS at a concentration of 100 mg/L during Cd stress resulted in increased biomass, reduced Cd accumulation and transport, and minimized the oxidative damage. EPS application also enhanced Cd retention in the shoot cell walls and root vacuoles, and actively altered the expression of genes involved in cell wall formation, antioxidant defense systems, transcription factors, and hormone metabolism. These findings provide new insights into EPS-mediated mitigation of Cd stress in plants and help us to develop strategies to improve crop yield in Cd-contaminated soils in the future.

Yeasts are used to produce several bioproducts, including functional bio-molecules, enzymes, biofuels, lipids, pigments, vitamins, organic acids, and other value-added bioproducts. When the production of the bioproduct occurs intracellularly, methods of disruption are traditionally used (mechanical and non-mechanical), which promote the release of bioproducts, but also the total degradation of the cell wall with consequent loss of yeast viability. As an alternative, cell permeabilization methods can be used through the use of external agents (chemical or physical), which form pores that increase the transfer of the product through the membrane, facilitating the separation of material, increasing the production of metabolites and also acting as an effective way of maintaining cellular viability - at least partially. In this review, we summarize the advances in yeast cell wall permeabilization compared to traditional methods of cell rupture. We also present the methods available for evaluating cell disruption and yeast permeabilization for yeast.

The alcohol-insoluble residue in Vanilla dressleri, V. odorata, V. planifolia and V. pompona mature leaves was fractionated into water-, oxalate-, HCl- and NaOH-soluble pectins, hemicellulose and lignocellulose. Neutral sugars and uronic acids of each fraction were determined by high-performance anion exchange chromatography-pulsed amperometric detection. V. dressleri differentiated from the other three species based on the higher amounts of the HCl-soluble pectin fraction and the amount of glucose exceeding 5–7 times the values found in the NaOH-soluble pectin fraction in the other species, as well as a cellulose/hemicellulose ratio of ca. 2/3. Analogously, V. planifolia could also be distinguished by its higher cellulose/hemicellulose ratio of ca. 7. In addition to taxonomical implications, these results might be instrumental for defining adequate conditions for cell wall digestion aiming at protoplast isolation and appropriate media composition for cell wall regeneration during protoplast culture, which has been elusive in the Orchidaceae.

Starch digestibility in whole pulses is affected by food structural characteristics, which in turn can be modulated by processing methods. In present study, high-pressure steam (HPS) and hydrothermal treatment (HT) with different moisture content were applied to clarify the mechanisms of processing variables affecting in vitro starch digestibility in pulse cells. Based on thermal and X-ray results, the relative crystallinity of cells decreased after HPS and HT treatments. However, HPS-treated cells under higher (>50%) moisture content showed insignificant discrepancies in crystallinity than HT samples. Starch digestion in HPS-treated cells increased with higher moisture content but was still lower than in HT samples. Results of FITC-dextran diffusion and methyl esterification of cell walls indicated that cells with higher wall permeability exhibited relatively higher starch digestibility. This study suggests that the enzyme susceptibility to starch in cells is dominantly influenced by cell wall structure, which could be optimized through processing variables.

Forests are crucial sustainable sources of natural ecosystems and contribute to human welfare. Cunninghamia lanceolata (Chinese fir) is an economically important conifer and occupies the largest area in China that produces global wood resources. Although Chinese fir has high economic value in China, little information is known regarding its mechanisms of wood formation. Therefore, transcriptome analysis was conducted to study the gene expression patterns and associated timber formation mechanisms in Chinese fir at different stand ages. In the present study, a total of 837,156 unigenes were identified in 84 samples from Chinese fir (pith and root) at different stand ages via RNA-Seq. Among them, most of the differentially expressed genes (DEGs) were significantly enrichment in plant hormone signal transduction, flavonoid metabolism pathway, starch and sucrose metabolism, and MAPK signal transduction pathway, which might be associated with the diameter formation in Chinese fir. The DEGs in these pathways were analyzed in Chinese fir and were related to lignin synthesis, cell wall formation and cell wall reinforcement/thickening. These genes might play an important role in regulating timber formation/growth in Chinese fir. In addition, certain transcriptome factors (TFs) related to Chinese fir timber formation were identified, including WRKY33, WRKY22, PYR/PYL, and MYC2. Weighted co-expression network analysis (WGCNA) showed that glucan endo-1,3-beta-d-glucosidase was a hub gene significantly correlated with the growth-related genes in Chinese fir. Sixteen key genes that related to diameter regulation in Chinese fir were verified by qRT-PCR analysis. These key genes might have a fine regulatory role in timber formation in Chinese fir. Our results pave the way for research on the regulatory mechanisms of wood formation, and provide an insight for improving the quality production of Chinese fir.

Understanding the impact of mildew on lignin and hemicelluloses within plant cell walls is crucial for addressing biomass degradation and antimicrobial studies. In this work, Two-dimensional nuclear magnetic resonance (2D NMR) and nanoindentation techniques were used to characterize the effects of three mildew species-Aspergillus niger (AN), Trichoderma viride (TV), and Penicillium citrinum (PC)-on lignin and hemicelluloses within bamboo cell walls. 2D NMR detected bond changes, while nanoindentation measured mechanical decline. Results show that mildew infection causes surface discoloration and weakens bamboo's mechanical integrity. Among the three species, AN had the greatest impact, followed by TV and PC. At the macromolecular level, mildew infection reduces the molecular weight of hemicelluloses. Specifically, all three mildew species (AN, PC, and TV) displayed targeted degradation of arabinose side chains in hemicelluloses. Mildew infection also altered the lignin composition in bamboo, with AN and PC infections leading to an elevated syringyl-to-guaiacyl (S/G) ratio, indicating reduced lignin condensation. Notably, TV demonstrated a remarkable ability to selectively cleave resistant carbon‑carbon (β-β) bonds in lignin, which are typically harder to degrade than ester and ether bonds. In summary, this study reveals how mildew strains selectively degrade bamboo lignin and hemicelluloses, offering insights into biomass use and plant-microbe interactions., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2025 Elsevier B.V. All rights reserved.)

Phosphoglucomutase (PGM) is considered an essential catalyst in polysaccharide biosynthesis, plays a pivotal role in the early stage of carbon metabolism and the synthesis of nucleotide sugars. Polysaccharides are important active components of Sanghuangporus vaninii. Based on the transcriptomic data, the successful cloning and re-annotation of the putative 1353 - bp PGM took place, which encodes a protein of 49.45 kDa. In order to elucidate the function of this gene, overexpression and interference transformation systems were constructed in S. vaninii. The results revealed that the PGM is primarily responsible for regulating the interconversion between glucose-1-phosphate and glucose-6-phosphate. An up - regulation of PGM expression resulted in a significant increase in extracellular polysaccharide content, quantified at 7.72 % and 15.15 %, whereas a down - regulation of PGM expression resulted in a significant increase in intracellular polysaccharide content (33.68 % and 38.24 %). The antioxidant capacity of intracellular polysaccharide in strain, including hydroxyl radical scavenging, superoxide anion radical scavenging, 2-diphenyl-1-picrylhydrazyl (DPPH) scavenging, ABTS + radical scavenging and FRAP scavenging was significantly increased by RNA interference with the expression of PGM, while the overexpression of PGM was found to enhance the antioxidant capacity of extracellular polysaccharide to a certain degrees. Furthermore, the modulation of PGM expression had a significant impact on polysaccharide metabolic pathways, resulting in alterations in monosaccharide composition and impacting the content of cell wall components, and the microstructure of polysaccharides. These findings elucidate the polysaccharide biosynthetic pathway in S. vaninii, highlighting the PGM as a prime target for the propagation of high-yield polysaccharide-producing strains. This study stands as a basic reference for amplifying polysaccharide production via strategic metabolic regulation., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2025 Elsevier B.V. All rights reserved.)

Tree hybridization is important in enhancing tree quality, adaptability, and genetic variability; however, the molecular basis of cell wall at the sublayer scale that contributes to superior performance remains unclear. This study adopted a new perspective and chose three poplar clones with parent-offspring relationship as material. The cellulose structure, lignin content, morphology of cells were analyzed, and the relationship between cell wall multi-layered structure and mechanical properties was explored. As the result, crystallinity of the Nanyang poplar, the hybrid progeny is the highest, ascribing to its larger crystallite width (3.90 nm) and length (9.02 nm), while its microfibril angle (MFA) is smaller and not significantly different from the parents (Clone No. 50, Clone No. 36) with low impact on its mechanical properties. Besides, Nanyang poplar with the highest thicker fiber cell wall and larger wall-to-lumen ratio. Superior microstructure result in Nanyang poplar with the highest macro-mechanical properties, including modulus of elasticity (MOE), modulus of rupture (MOR), hardness, compressive strength; as well as supreme cell wall mechanical properties. Correlation analysis results showed that, strongest correlation was observed between the degree of crystallinity and the macro-mechanical properties of wood, specifically MOE, MOR and compressive strength. Additionally, a significant correlation was found between lignin content and the hardness of wood., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2025 Elsevier B.V. All rights reserved.)

We report the case of a man in his 70s who developed invasive pneumococcal disease (IPD) caused by CO 2 -dependent Streptococcus pneumoniae. He was admitted with suspected pneumonia based on chest X-ray and computed tomography imaging findings. Ceftriaxone treatment was initiated following the collection of sputum samples and two sets of blood cultures. The antimicrobial treatment was then changed to sulbactam/ampicillin (SBT/ABPC) because urine pneumococcal antigen testing performed on admission was positive. The following day, CO 2 -dependent S. pneumoniae was isolated from the blood cultures and sputum sample, leading to a diagnosis of IPD. The patient continued SBT/ABPC treatment (6 g/day) but remained febrile and died 4 days after admission. Serotyping and whole-genome sequence analysis of the isolate revealed that it was serotype 24F and sequence type (ST) 162. A c.536C > T mutation was identified in murF of the isolate compared with S. pneumoniae Spain9V-3. The isolation of CO 2 -dependent S. pneumoniae serotype 24F ST162 from pediatric patients in Japan was recently reported. However, to the best of our knowledge, this is the first reported IPD case in an elderly patient caused by CO 2 -dependent S. pneumoniae serotype 24F ST162. Thus, even in adults with IPD, caution should be exercised going forward., Competing Interests: Declaration of interest There are no conflicts of interest to declare., (Copyright © 2025 Japanese Society of Chemotherapy, Japanese Association for Infectious Diseases, and Japanese Society for Infection Prevention and Control. Published by Elsevier Ltd. All rights reserved.)

Cassava cell flour can expand the food industrial availability of cassava resources. In this study, cassava cells were isolated from eight cassava varieties to analyze the composition, structure, and physicochemical properties. The smaller particle size in CS4 led to the lowest swelling power and viscosity, which further reduced the modulus (G', G") and shear stress of the cassava cell gel. The higher starch content in CS3 and CS8 (88.86 %, 87.99 %) increased the swelling and solubility of the cells, resulting in high viscosity and gel strength. Thicker cell walls presented a higher content of cell wall polysaccharides, hindering the interaction of water, heat, and digestive enzymes with intracellular starch, leading to higher gelatinization temperatures and lower digestion rates. In addition, the B1 chain promoted the formation of the starch crystalline region and increased the gelatinization temperature and enthalpy of cell flour. Based on cluster analysis and correlation analysis, the differences in the functional properties of cassava cell flour were related to cell components, morphology, and intracellular starch structure. The study provided a theoretical basis for the application of cassava cells in the food industry., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier B.V. All rights reserved.)

Xylan is a vital component of plant cell walls, contributing to their structural integrity and flexibility through interactions with other polymers. Its structure varies among plant species, influencing the mechanical properties of cell walls. Xylan also has significant industrial potential, including in biofuels, biomaterials, food, and pharmaceuticals, due to its ability to be converted into valuable bioproducts. However, key aspects of xylan biosynthesis, regulation, and structural impact on plant growth and structures remain unclear. This review highlights current researches on xylan biosynthesis, modification, and applications, identifying critical gaps in knowledge. Meanwhile the review proposes new approaches to regulate xylan synthesis and understand its role in cell wall assembly and interactions with other polymers. Addressing these gaps could unlock the full industrial potential of xylan, leading to more sustainable applications., Competing Interests: Declaration of competing interest The manuscript was edited and reviewed by all authors, and we declare that there is no conflict of interest., (Copyright © 2024 Elsevier B.V. All rights reserved.)

Lignin is a crucial constituent of cell walls and plays a pivotal role in plant growth and development. However, the transcriptional regulatory network governing lignin biosynthesis is not fully understood. In this study, we observed that PpnCCT39 overexpression resulted in greener stems, larger basal diameters, and increased stem dry weight. Additionally, the secondary xylem of lines overexpressing PpnCCT39 was wider, had larger xylem fiber cell areas, and thicker cell walls, compared to those of wild-type plants. Furthermore, PpnCCT39 overexpression led to elevated lignin content and enhanced the rigidity of secondary cell walls. RNA-seq and ChIP-seq association analyses identified 826 potential regulatory target genes of PpnCCT39 that were upregulated and expressed in 1-month-old PpnCCT39 overexpression lines. Gene enrichment analyses revealed enrichment in pathways related to cell wall formation, xylem and phloem development, and the phenylpropanoid pathway. Two genes involved in lignin biosynthesis, PagCOMT1 and PagBGLU18-2, exhibited significantly increased expression in stems of lines overexpressing PpnCCT39, as demonstrated by high FPKM values and RT-qPCR results. Further investigations using yeast one-hybrid, dual-luciferase assays, and electrophoretic mobility shift assays demonstrated that PpnCCT39 directly activates the transcription of PagCOMT1 and PagBGLU18-2, thereby promoting lignin biosynthesis. This study elucidated the transcriptional regulatory mechanism of PpnCCT39 in poplars and revealed its role in activating the expression of key lignin biosynthesis genes. PpnCCT39 facilitates lignin biosynthesis and secondary growth processes, offering a novel theoretical framework for modulating lignin biosynthesis and enhancing timber yield through molecular design., Competing Interests: Declaration of competing interest The authors declare no conflict of interest., (Copyright © 2024 Elsevier B.V. All rights reserved.)