Altered Cell Wall Structure Research Articles

Passive protection of chicken egg yolk immunoglobulin (IgY) against Streptococcus agalactiae infection in Nile tilapia (Oreochromis niloticus)

IgY is an immunoglobulin primarily found in the serum and egg yolk of birds, amphibians, and reptiles. Recent years, IgY is considered to have a good application prospect in the immunodiagnostics and passive immunotherapy of aquatic diseases. In this study, we prepared a specific IgY against Streptococcus agalactiae in tilapia after immunizing the hens for 4 times. The result of ELISA detection showed that the IgY titers in water-soluble fraction (WSF) after 6 weeks of immunization reached 1:51200 and last for 4 weeks. Western blot (WB) analysis data showed that the specific IgY could recognize the target band, the specific IgY showed a concentration-dependent inhibitory effect on the growth of S. agalactiae, altered cell wall structure and aggluted of S. agalactiae. The quantitative reverse transcription PCR (qRT-PCR) analysis data suggested that the specific IgY downregulated the expression of pro-inflammatory factors (IL-8, TNF-α), upregulated the anti-inflammatory factors (IL-10, TGF-β). In addition, the histopathological results showed that the specific IgY significantly decreased the pathological manifestations, dramatically improved the survival rates of tilapia in injection, feeding, and immersion experiments. Collectively, our findings demonstrated that the broad potential of specific IgY for the prevention and treatment of S. agalactiae infection in tilapia.

Foliar application of myo-inositol inhibits the growth of trifoliate orange (Poncirus trifoliata) seedlings by inducing alterations in cell wall structure and energy metabolism disorders

Foliar application of myo-inositol inhibits the growth of trifoliate orange (Poncirus trifoliata) seedlings by inducing alterations in cell wall structure and energy metabolism disorders

Nanoplastics increase algal absorption and toxicity of Cd through alterations in cell wall structure and composition

Nanoplastics (NPs) may act as carriers of heavy metals and cause complex toxicity to aquatic organisms, while the exact role of NPs in the joint toxicity remains unclear. Here, we investigated the joint toxicity of polystyrene NPs (PS-NPs) and Cd to freshwater algae (Chlorella vulgaris). It was found that PS-NPs (1 mg L−1) could hardly enter algal cells and slightly inhibit algal growth (p < 0.01). The effect of PS-NPs as carriers on the joint toxicity of PS-NPs and heavy metals could be neglected because of the limited adsorption of Cd by PS-NPs, while the PS-NPs altered the cell wall structure and composition, which resulted in the increased algal absorption and toxicity of Cd. Compared to the low dose Cd (0.4 mg L−1) treatment alone, the extracellular and intracellular Cd contents in the cotreatment were significantly increased by 27.3 % and 18.0 %, respectively, due to the increased contents of cell wall polysaccharides (pectin and hemicellulose in particular) by the PS-NPs. Furthermore, after the high dose Cd (2 mg L−1) exposure, the inhibited polysaccharide biosynthesis and the loosen cell wall structure weakened the tolerance of cell wall to abiotic stress, facilitating the entry of PS-NPs into the algal cells and inducing the higher toxicity. These results elucidate the mechanism by which NPs enhance heavy metal toxicity to algae, providing a novel insight into environmental risks of NPs.

Unveiling the intricate mechanisms of plant defense

Plants may lack mobility, but they are not defenseless against the constant threats posed by pathogens and pests. Pattern Recognition Receptors (PRRs), which are located on the plasma membrane, enable plants to effectively recognize intruders. These receptors function by sensing elicitors or fragments of the cell wall that arise from damage. Recent studies underscore the significance of maintaining cell wall integrity in the coordination of defense mechanisms following the detection of parasitism. Pathogen invasion often triggers alterations in cell wall structure, which leads to the release of molecules like β-glucans and oligogalacturonides. These small molecules are then recognized by PRRs, which stimulate downstream signaling pathways that involve both receptor-like kinases and calcium-dependent signaling. Here, we present the latest insights into plant signaling that play a vital role in immunity: the maintenance of cell wall integrity; the intricate interplay between receptor-like kinases; and the involvement of calcium ions. The goal of the review is to provide readers with a deeper understanding of the intricate mechanisms underlying plant defense strategies.

Ripening induced degradation of pectin and cellulose affects the far infrared drying kinetics of mangoes

The quality parameters of mangoes change during ripening, which has a vital impact on processing characteristics. Effects of ripening stage (four stages from the lowest to highest degree—RS-1, RS-2, RS-3, RS-4) on cell wall polysaccharides and far infrared drying kinetics of mangoes were investigated. As ripening progressed, the water-soluble pectin contents increased by 213.5%; while the chelate-, sodium carbonate-soluble pectin and hemicellulose contents decreased by 44.0%, 59.5% and 65.8%, respectively. Moreover, the molecular weight reduction confirmed the degradation of pectin. These further caused the alteration of cell wall structure and changes in water distribution. Meanwhile, the drying time of mangos with different ripeness were in the order: RS-3 > RS-4 > RS-2 > RS-1. It correlated with the degradation of cell wall polysaccharides, the destruction of cell wall and the increases in free water during ripening. The ripeness classification could effectively improve the uniformity and efficiency of fruits drying processing.

Morphological Characterization and Transcriptome Analysis of New Dwarf and Narrow-Leaf (dnl2) Mutant in Maize

Lodging is the primary factor limiting high yield under a high plant density. However, an optimal plant height and leaf shape can effectively decrease the lodging risk. Here we studied an ethyl methanesulfonate (EMS)-induced dwarf and a narrow-leaf mutant, dnl2. Gene mapping indicated that the mutant was controlled by a gene located on chromosome nine. Phenotypic and cytological observations revealed that dnl2 showed inhibited cell growth, altered vascular bundle patterning, and disrupted secondary cell wall structure when compared with the wild-type, which could be the direct cause of the dwarf and narrow-leaf phenotype. The phytohormone levels, especially auxin and gibberellin, were significantly decreased in dnl2 compared to the wild-type plants. Transcriptome profiling of the internodes of the dnl2 mutant and wild-type revealed a large number of differentially expressed genes enriched in the cell wall biosynthesis, remodeling, and hormone biosynthesis and signaling pathways. Therefore, we suggest that crosstalk between hormones (the altered vascular bundle and secondary cell wall structure) may contribute to the dwarf and narrow-leaf phenotype by influencing cell growth. These results provide a foundation for DNL2 gene cloning and further elucidation of the molecular mechanism of the regulation of plant height and leaf shape in maize.

PtrLAC16 plays a key role in catalyzing lignin polymerization in the xylem cell wall of Populus

Plant laccases have been proposed to participate in lignin biosynthesis. However, there is no direct evidence that individual laccases in Populus can polymerize lignin monomers and alter cell wall structure. Here, a Populus laccase, PtrLAC16, was expressed and purified in a eukaryotic system. Enzymatic analysis of PtrLAC16 showed that it could polymerize lignin monomers in vitro. PtrLAC16 preferred sinapyl alcohol, and this preference is associated with an altered S/G ratio in transgenic Populus lines. PtrLAC16 was localized exclusively in the cell walls of stem vascular tissue, and a reduction in PtrLAC16 expression led to a significant decrease in lignin content and altered cell wall structure. There was a direct correlation between the inhibition of PtrLAC16 expression and structural changes in the stem cell wall of Populus. This study provides direct evidence that PtrLAC16 plays a key role in the polymerization of lignin monomers, especially for sinapyl lignin, and affects the formation of xylem cell walls in Populus.

Cell wall structure and composition is affected by light quality in tomato seedlings

Light affects many aspects of cell development. Tomato seedlings growing at different light qualities (white, blue, green, red, far-red) and in the dark displayed alterations in cell wall structure and composition. A strong and negative correlation was found between cell wall thickness and hypocotyl growth. Cell walls was thicker under blue and white lights and thinner under far-red light and in the dark, while intermediate values was observed for red or green lights. Additionally, the inside layer surface of cell wall presented random deposited microfibrillae angles under far-red light and in the dark. However, longitudinal transmission electron microscopy indicates a high frequency of microfibrils close to parallels related to the elongation axis in the outer layer. This was confirmed by ultra-high resolution small angle X-ray scattering. These data suggest that cellulose microfibrils would be passively reoriented in the longitudinal direction. As the cell expands, the most recently deposited layers (inside) behave differentially oriented compared to older (outer) layers in the dark or under FR lights, agreeing with the multinet growth hypothesis. High Ca and pectin levels were found in the cell wall of seedlings growing under blue and white light, also contributing to the low extensibility of the cell wall. Low Ca and pectin contents were found in the dark and under far-red light. Auxins marginally stimulated growth in thin cell wall circumstances. Hypocotyl growth was stimulated by gibberellins under blue light.

Ethanol induced jasmonate pathway promotes astaxanthin hyperaccumulation in Haematococcus pluvialis

Haematococcus pluvialis is a main biological resource for the antioxidant astaxanthin production, however, potential modulators and molecular mechanisms underpinning astaxanthin accumulation remain largely obscured. We discovered that provision of ethanol (0.4%) significantly triggered the cellular astaxanthin content up to 3.85% on the 4th day of treatment. Amongst, 95% of the accumulated astaxanthin was esterified, particularly enriched with monoesters. Ultrastructural analysis revealed that ethanol altered cell wall structure and physiological properties. Antioxidant analyses revealed that astaxanthin accumulation offset the ethanol induced oxidative stress. Ethanol treatment reduced carbohydrates while increased lipids and jasmonic acid production. Transcriptomic analysis uncovered that ethanol orchestrated the expression of crucial genes involved in carotenogenesis, e.g. PSY, BKT and CRTR-b were significantly upregulated. Moreover, methyl jasmonic acid synthesis was induced and played a major role in regulating the carotenogenic genes. The findings uncovered the novel viewpoint in the intricate transcriptional regulatory mechanisms of astaxanthin biosynthesis.

Excess boron inhibited the trifoliate orange growth by inducing oxidative stress, alterations in cell wall structure, and accumulation of free boron

The boron (B) is an essential nutrient and plays an important role in the stability of the primary cell wall (CW). Due to the narrow window between B deficiency and toxicity, mismanagement practices lead to B toxicity that inhibit root growth and overall crop productivity. However, the exact cause of root growth inhibition remains unclear. The present study examined the potential causes and targets of B toxicity by studying intercellular mechanism. The trifoliate seedlings were cultured under excess B conditions. The results indicated that plant growth was inhibited by excess B, nevertheless, the effects were prominent on roots and leaves. B toxicity exacerbated oxidative stress and root cell death. The analysis of CW functional groups, CW microstructure and B forms lead to the conclusion that alterations in CW, and accumulation of free-B and carbohydrates might cause inhibition of growth and visible symptoms of B toxicity.

Boron increases root elongation by reducing aluminum induced disorganized distribution of HG epitopes and alterations in subcellular cell wall structure of trifoliate orange roots

Aluminum toxicity limits the plant growth by inducing inhibition of root elongation. Although several mechanisms have been proposed regarding the phytotoxic effects of aluminum on inhibition of root elongation; the primary causes of aluminum induced root inhibition and its mitigation by boron (B) are still elusive. The present study was carried out to explore the mechanisms of B induced mitigation of aluminum toxicity and to investigate the changes in well wall structure under aluminum toxicity coupled with the techniques of confocal laser microscope, lumogallion and transmission electron microscope. The results revealed that aluminum toxicity severely hampered the root elongation and plant biomass. Moreover, alteration in subcellular structure were observed under aluminum toxicity, however, such negative effects were further exacerbated with B deficiency. Aluminum toxicity indicated disorganized distribution of HG (homogalacturonan) epitopes with higher accumulation of apoplastic aluminum. Nevertheless, B supply improved root elongation, and reduced the aluminum uptake. Taken together, it is concluded that B application can reduce aluminum toxicity and improve root elongation by decreasing Al3+ accumulation to cell wall, alteration in the cell wall structure and reducing the distribution of HG epitopes in the roots of trifoliate (Poncirus trifoliate) orange.

Long-term cadmium exposure influences the abundance of proteins that impact the cell wall structure in Medicago sativa stems.

Cadmium (Cd) is a non‐essential, toxic heavy metal that poses serious threats to both ecosystems and human health. Plants employ various cellular and molecular mechanisms to minimise the impact of Cd toxicity and cell walls function as a defensive barrier during Cd exposure.In this study, we adopted a quantitative gel‐based proteomic approach (two‐dimensional difference gel electrophoresis) to investigate changes in the abundance of cell wall and soluble proteins in stems of Medicago sativa L. upon long‐term exposure to Cd (10 mg·Cd·kg−1 soil as CdSO 4). Obtained protein data were complemented with targeted gene expression analyses.Plants were affected by Cd exposure at an early growth stage but seemed to recover at a more mature stage as no difference in biomass was observed. The accumulation of Cd was highest in roots followed by stems and leaves. Quantitative proteomics revealed a changed abundance for 179 cell wall proteins and 30 proteins in the soluble fraction upon long‐term Cd exposure. These proteins are involved in cell wall remodelling, defence response, carbohydrate metabolism and promotion of the lignification process.The data indicate that Cd exposure alters the cell wall proteome and underline the role of cell wall proteins in defence against Cd stress. The identified proteins are linked to alterations in cell wall structure and lignification process in stems of M. sativa, underpinning the function of the cell wall as an effective barrier against Cd stress.

Cell wall-bound silicon optimizes ammonium uptake and metabolism in rice cells.

Turgor-driven plant cell growth depends on cell wall structure and mechanics. Strengthening of cell walls on the basis of an association and interaction with silicon (Si) could lead to improved nutrient uptake and optimized growth and metabolism in rice (Oryza sativa). However, the structural basis and physiological mechanisms of nutrient uptake and metabolism optimization under Si assistance remain obscure. Single-cell level biophysical measurements, including in situ non-invasive micro-testing (NMT) of NH4+ ion fluxes, atomic force microscopy (AFM) of cell walls, and electrolyte leakage and membrane potential, as well as whole-cell proteomics using isobaric tags for relative and absolute quantification (iTRAQ), were performed. The altered cell wall structure increases the uptake rate of the main nutrient NH4+ in Si-accumulating cells, whereas the rate is only half in Si-deprived counterparts. Rigid cell walls enhanced by a wall-bound form of Si as the structural basis stabilize cell membranes. This, in turn, optimizes nutrient uptake of the cells in the same growth phase without any requirement for up-regulation of transmembrane ammonium transporters. Optimization of cellular nutrient acquisition strategies can substantially improve performance in terms of growth, metabolism and stress resistance.

Production of fluorescent and cytotoxic K28 killer toxin variants through high cell density fermentation of recombinant Pichia pastoris

BackgroundVirus infected killer strains of the baker’s yeast Saccharomyces cerevisiae secrete protein toxins such as K28, K1, K2 and Klus which are lethal to sensitive yeast strains of the same or related species. K28 is somewhat unique as it represents an α/β heterodimeric protein of the A/B toxin family which, after having bound to the surface of sensitive target cells, is taken up by receptor-mediated endocytosis and transported through the secretory pathway in a retrograde manner. While the current knowledge on yeast killer toxins is largely based on genetic screens for yeast mutants with altered toxin sensitivity, in vivo imaging of cell surface binding and intracellular toxin transport is still largely hampered by a lack of fluorescently labelled and biologically active killer toxin variants.ResultsIn this study, we succeeded for the first time in the heterologous K28 preprotoxin expression and production of fluorescent K28 variants in Pichia pastoris. Recombinant P. pastoris GS115 cells were shown to successfully process and secrete K28 variants fused to mCherry or mTFP by high cell density fermentation. The fluorescent K28 derivatives were obtained in high yield and possessed in vivo toxicity and specificity against sensitive yeast cells. In cell binding studies the resulting K28 variants caused strong fluorescence signals at the cell periphery due to toxin binding to primary K28 receptors within the yeast cell wall. Thereby, the β-subunit of K28 was confirmed to be the sole component required and sufficient for K28 cell wall binding.ConclusionSuccessful production of fluorescent killer toxin variants of S. cerevisiae by high cell density fermentation of recombinant, K28 expressing strains of P. pastoris now opens the possibility to study and monitor killer toxin cell surface binding, in particular in toxin resistant yeast mutants in which toxin resistance is caused by defects in toxin binding due to alterations in cell wall structure and composition. This novel approach might be easily transferable to other killer toxins from different yeast species and genera. Furthermore, the fluorescent toxin variants described here might likewise represent a powerful tool in future studies to visualize intracellular A/B toxin trafficking with the help of high resolution single molecule imaging techniques.

Aspergillus fumigatus Trehalose-Regulatory Subunit Homolog Moonlights To Mediate Cell Wall Homeostasis through Modulation of Chitin Synthase Activity.

ABSTRACTTrehalose biosynthesis is found in fungi but not humans. Proteins involved in trehalose biosynthesis are essential for fungal pathogen virulence in humans and plants through multiple mechanisms. Loss of canonical trehalose biosynthesis genes in the human pathogen Aspergillus fumigatus significantly alters cell wall structure and integrity, though the mechanistic link between these virulence-associated pathways remains enigmatic. Here we characterize genes, called tslA and tslB, which encode proteins that contain domains similar to those corresponding to trehalose-6-phosphate phosphatase but lack critical catalytic residues for phosphatase activity. Loss of tslA reduces trehalose content in both conidia and mycelia, impairs cell wall integrity, and significantly alters cell wall structure. To gain mechanistic insights into the role that TslA plays in cell wall homeostasis, immunoprecipitation assays coupled with liquid chromatography-tandem mass spectrometry (LC-MS/MS) were used to reveal a direct interaction between TslA and CsmA, a type V chitin synthase enzyme. TslA regulates not only chitin synthase activity but also CsmA sub-cellular localization. Loss of TslA impacts the immunopathogenesis of murine invasive pulmonary aspergillosis through altering cytokine production and immune cell recruitment. In conclusion, our data provide a novel model whereby proteins in the trehalose pathway play a direct role in fungal cell wall homeostasis and consequently impact fungus-host interactions.

DkXTH8, a novel xyloglucan endotransglucosylase/hydrolase in persimmon, alters cell wall structure and promotes leaf senescence and fruit postharvest softening.

Fruit softening is mainly associated with cell wall structural modifications, and members of the xyloglucan endotransglucosylase/hydrolase (XTH) family are key enzymes involved in cleaving and re-joining xyloglucan in the cell wall. In this work, we isolated a new XTH gene, DkXTH8, from persimmon fruit. Transcriptional profiling revealed that DkXTH8 peaked during dramatic fruit softening, and expression of DkXTH8 was stimulated by propylene and abscisic acid but suppressed by gibberellic acid and 1-MCP. Transient expression assays in onion epidermal cells indicated direct localization of DkXTH8 to the cell wall via its signal peptide. When expressed in vitro, the recombinant DkXTH8 protein exhibited strict xyloglucan endotransglycosylase activity, whereas no xyloglucan endohydrolase activity was observed. Furthermore, overexpression of DkXTH8 resulted in increased leaf senescence coupled with higher electrolyte leakage in Arabidopsis and faster fruit ripening and softening rates in tomato. Most importantly, transgenic plants overexpressing DkXTH8 displayed more irregular and twisted cells due to cell wall restructuring, resulting in wider interstitial spaces with less compact cells. We suggest that DkXTH8 expression causes cells to be easily destroyed, increases membrane permeability and cell peroxidation, and accelerates leaf senescence and fruit softening in transgenic plants.

A Novel FC116/BC10 Mutation Distinctively Causes Alteration in the Expression of the Genes for Cell Wall Polymer Synthesis in Rice.

We report isolation and characterization of a fragile culm mutant fc116 that displays reduced mechanical strength caused by decreased cellulose content and altered cell wall structure in rice. Map-based cloning revealed that fc116 was a base substitution mutant (G to A) in a putative beta-1,6-N-acetylglucosaminyltransferase (C2GnT) gene (LOC_Os05g07790, allelic to BC10). This mutation resulted in one amino acid missing within a newly-identified protein motif “R, RXG, RA.” The FC116/BC10 gene was lowly but ubiquitously expressed in the all tissues examined across the whole life cycle of rice, and slightly down-regulated during secondary growth. This mutant also exhibited a significant increase in the content of hemicelluloses and lignins, as well as the content of pentoses (xylose and arabinose). But the content of hexoses (glucose, mannose, and galactose) was decreased in both cellulosic and non-cellulosic (pectins and hemicelluloses) fractions of the mutant. Transcriptomic analysis indicated that the typical genes in the fc116 mutant were up-regulated corresponding to xylan biosynthesis, as well as lignin biosynthesis including p-hydroxyphenyl (H), syringyl (S), and guaiacyl (G). Our results indicate that FC116 has universal function in regulation of the cell wall polymers in rice.

Proteomic analysis reveals growth inhibition of soybean roots by manganese toxicity is associated with alteration of cell wall structure and lignification

Plant roots, the hidden half of plants, play a vital role in manganese (Mn) toxicity tolerance. However, molecular mechanisms underlying root adaptation to Mn toxicity remain largely unknown. In this study, soybean (Glycine max) was used to investigate alterations of root morphology and protein profiles in response to Mn toxicity. Results showed that soybean root growth was significantly inhibited by Mn toxicity. Subsequent proteomic analysis revealed that 31 proteins were successfully identified via MALDI TOF/TOF MS analysis including 21 unique up-regulated and 6 unique down-regulated proteins, which are mainly related to cell wall metabolism, protein metabolism and signal transduction. qRT-PCR analysis revealed that corresponding gene transcription patterns were correlated with accumulation of 14 of 21 up-regulated proteins, but only 1 of 6 down-regulated proteins, suggesting that most excess Mn up-regulated proteins are controlled at the transcriptional levels, while down-regulated proteins are controlled at the post-transcriptional levels. Furthermore, changes in abundances of GTP-binding nuclear protein Ran-3, expansin-like B1-like protein, dirigent protein and peroxidase 5-like protein strongly suggested that alteration of root cell wall structure and lignification might be associated with inhibited root growth. Taken together, this study was helpful to further understandings of adaptive strategies of legume roots to Mn toxicity. SignificanceThis study highlighted the effects of Mn toxicity on soybean root growth and its proteome profiles. Excess Mn treatments inhibited root growth. Comparative proteomic analysis was performed to analyze the changes in protein profiles of soybean roots in response to Mn toxicity. A total of 31 root proteins with differential abundances were identified and predominantly associated with signal transduction and cell wall metabolism. Among them, the abundances of the GTP-binding nuclear protein Ran-3 and Ran-binding protein 1 were significantly increased, suggesting that the proteins could be involved in the signaling network in soybean roots responsive to Mn toxicity. Interestingly, three 14-3-3 proteins were decreased by excess Mn at protein but not mRNA levels, suggesting that these proteins could be regulated at post-transcriptional modification under Mn excess conditions. Furthermore, changes in abundances of expansin-like B1-like protein, peroxidase 5-like protein, dirigent protein 2-like protein and dirigent protein strongly suggested that Mn toxicity could influence root cell wall modification, and thus inhibit root growth. This study provided significant insights into the potential molecular mechanisms underlying soybean root adaptation to Mn toxicity, which was mainly through alteration of root cell wall structure and lignification.

Biochar filters reduced the toxic effects of nickel on tomato (Lycopersicon esculentum L.) grown in nutrient film technique hydroponic system

This work used the nutrient film technique to evaluate the role of biochar filtration in reducing the toxic effects of nickel (Ni2+) on tomato growth. Three hydroponic treatments: T1 (control), T2 (with Ni2+), and T3 (with Ni2+ and biochar) were used in the experiments. Scanning electron microscopy equipped with energy dispersive X-ray spectroscopy and Fourier transform spectroscopy was used to characterize the pre- and post-treatment biochar samples. The results illustrated that precipitation, ion exchange, and complexation with surface functional groups were the potential mechanisms of Ni2+ removal by biochar. In comparison to the control, the T2 treatment showed severe Ni-stress with alterations in cell wall structure, distortions in cell nucleus, disturbances in mitochondrial system, malformations in stomatal structure, and abnormalities in chloroplast structure. The biochar filters in T3 treatment reduced dysfunctions of cell organelles in root and shoot cells. Total chlorophyll concentration decreased by 41.6% in T2 treatment. This reduction, however, was only 20.8% due to the protective effect of the biochar filters. The presence of Ni2+ in the systems reduced the tomato fruit yield 58.5% and 31.9% in T2 and T3, respectively. Nickel concentrations reached the toxic limit in roots, shoots, and fruits in T2, which were not observed in T3. Biochar filters in T3 also minimized the dramatic reductions in nutrients concentration in roots, shoots, and fruits, which occurred in T2 treatment due to the severe Ni-stress. Findings from this work suggested that biochar filters can be used on farms as a safeguard for wastewater irrigation.

Hyperproduction of β-Glucanase Exg1 Promotes the Bioconversion of Mogrosides in Saccharomyces cerevisiae Mutants Defective in Mannoprotein Deposition.

Bacteria and fungi can secrete extracellular enzymes to convert macromolecules into smaller units. Hyperproduction of extracellular enzymes is often associated with alterations in cell wall structure in fungi. Recently, we identified that Saccharomyces cerevisiae kre6Δ mutants can efficiently convert mogroside V into mogroside III E, which has antidiabetic properties. However, the underlying efficient bioconversion mechanism is unclear. In the present study, the mogroside (MG) bioconversion properties of several cell wall structure defective mutants were analyzed. We also compared the cell walls of these mutants by transmission electron microscopy, a zymolyase sensitivity test, and a mannoprotein release assay. We found zymolyase-sensitive mutants (including kre1Δ, las21Δ, gas1Δ, and kre6Δ), with defects in mannoprotein deposition, exhibit efficient MG conversion and excessive leakage of Exg1; such defects were not observed in wild-type cells, or mutants with abnormal levels of glucans in the cell wall. Thus, yeast mutants defective in mannoprotein deposition may be employed to convert glycosylated bioactive compounds.