Search Results (112)

Cellulose is the strongest cell wall polymer defining plant cell shape and growth, and the most abundant biopolymer on the Earth. Its synthesis by the plasma membrane (PM)-localized cellulose synthase complexes (CSCs) depends on surrounding lipids that establish the membrane microenvironment in which CSCs work and form vesicles delivering and removing CSCs to and from the PM by exo- and endocytosis. The role of exact lipid molecular species in these processes is poorly understood. In the present work we used hypocotyls of etiolated wild-type Col-0 and mutant ixr1-1 Arabidopsis thaliana seedlings grown with or without isoxaben, a specific cellulose synthesis inhibitor, as a model to reveal lipid molecular species associated with cellulose biosynthesis. Different lipid classes were separated by thin-layer chromatography (TLC) and their molecular species were analyzed by liquid chromatography–triple quadrupole tandem mass spectrometry (LC-QqQ-MS/MS). A total of 250 lipid molecular species were identified. Col-0 plants maintained stable levels of membrane glycerophospholipids but displayed significant remodeling of their acyl chains. In the presence of isoxaben, they accumulated three times more phosphatidic acids, a hallmark of a stress response. The isoxaben-resistant mutant ixr1-1 was characterized by a higher relative content of phosphatidylethanolamines, potentially rendering membranes more labile, as well as plastid galactolipids, which accumulated under isoxaben treatment. The multifaceted effects of isoxaben, including its impact on endomembrane lipids, suggest that it has additional binding sites beyond CSC. Full article

The cellulose synthase gene superfamily encompasses two major groups, CesA and Csl, which are vital for synthesizing cellulose and hemicellulose in plant cell walls and fundamental to plant growth and developmental regulation. Madhuca pasquieri is a rare tree with high timber value. Currently, there is no relevant report on the identification and characterization of the CesA/Csl gene family in M. pasquieri. In this study, based on the high-quality genome of M. pasquieri, 47 members of the CesA/Csl superfamily were identified and classified into seven subfamilies, including CesA, CslA, CslB, CslC, CslD, CslE and CslG. Cis-acting elements were identified via analysis of the 2000 bp upstream sequences of MpCesA, suggesting extensive involvement in biotic and abiotic stress regulation. Based on the transcriptome data of five growth periods, the expression of the CesA/Csl family was analyzed. Combined with phylogenetic information, it is inferred that MpCesA4/7b/7a/8b may regulate the secondary wall, while MpCesA1/3b/6b may regulate the primary wall. Protein–protein interaction showed that MpCesA4/7b/8a were in the core site. Finally, we constructed the cellulose synthase complex (MpCesA4/7b/8b) model using AlphaFold3, which suggests that MpCesA4/7b/8b may form a complex on the plasma membrane to carry out cellulose synthesis. This study has a limitation in that the complex and its expression lack experimental validation, and only data analysis is provided as a reference, offering some directions for future research. In summary, the systematic characterization of the MpCesA/Csl gene family provides important insights into cell wall formation, genetic enhancement, and future biotechnological applications of this species. Full article

Isoprene, a highly volatile hydrocarbon with numerous industrial applications, has traditionally been produced from petrochemical sources through processes associated with significant environmental impacts. Microbial production of isoprene has emerged as a promising and more sustainable alternative. In this study, the potential of the non-conventional yeast Kluyveromyces marxianus to produce isoprene from a renewable feedstock was explored, contributing to the development of a more sustainable process. K. marxianus was engineered to produce isoprene from glucose through the expression of an isoprene synthase gene, and the gene copy number of this enzyme was found to significantly influence isoprene production. Furthermore, enhancing the supply of the isoprene precursors acetyl-CoA and dimethylallyl diphosphate (DMAPP) via engineering of the mevalonate pathway led to increased production. A higher headspace-to-culture ratio in sealed serum bottles also facilitated isoprene accumulation. Importantly, isoprene production was achieved from the cellulosic fraction of pretreated Eucalyptus globulus wood. To our knowledge, this is the first report of isoprene production in K. marxianus using a lignocellulosic feedstock, providing proof of concept for its potential in integrated processes based on sustainable substrates under stressful conditions. Full article

The toxicity of copper (Cu) severely affects the growth and physiological metabolism of plants. 2-(3,4-Dichlorophenoxy) triethylamine (DCPTA) is a plant growth regulator known to enhance plant tolerance to various abiotic stresses; however, its specific role in mitigating Cu toxicity via cell wall modulation and nitrogen metabolism remains unclear. “Zhongnong 26” (Cucumis sativus L.) seedlings were subjected to a randomized block design with four treatments: control (CK), 0.25 mg/L DCPTA, 50 μM Cu, and 50 μM Cu + 0.25 mg/L DCPTA, with three biological replicates per treatment. The results indicated that DCPTA application significantly alleviated Cu-induced growth inhibition. Specifically, DCPTA improved root system architecture by markedly increasing total root length (68.8%), surface area (68.7%), and the number and length of secondary lateral roots (69.6%, 173.2%). Furthermore, DCPTA enhanced the biosynthesis of cell wall polysaccharides—including pectin (24.3%), hemicellulose 1 (22.4%), hemicellulose 2 (23.7%) and cellulose (33.1%) in roots. Fourier Transform Infrared (FTIR) spectroscopy analysis revealed that DCPTA modified functional groups (e.g., –OH, –COOH) within the cell wall, enhancing their metal-chelating capacity. Consequently, DCPTA promoted the immobilization of Cu in the root cell wall fractions (particularly pectin and HC2) and shifted Cu into less toxic, pectate- and protein-bound forms, thereby reducing its translocation to leaves. Additionally, DCPTA restored the activities of key nitrogen metabolism enzymes in leaves and roots. Compared with Cu treatment alone, nitrate reductase (NR) activity increased by 77.7% and 90.6%, while glutamine synthetase (GS) activity remained stable, and glutamate synthase (GOGAT) activity increased by 10.3% and 71.3% in leaves and roots, respectively. In conclusion, DCPTA enhances copper sequestration in roots by coordinating the regulation of root structure and cell wall strengthening (with an increase in pectin and hemicellulose content). This is crucial for protecting the nitrogen metabolism within the cells (including the enzymes that drive the nitrate–ammonium reduction pathway) to maintain metabolic balance under Cu stress. Full article

Excessive nitrogen (N) fertilization is widely used to increase rice yield, but it often leads to lodging by weakening culm strength. This study aimed to elucidate the structural and molecular mechanisms underlying nitrogen-induced changes in culm lodging resistance in rice. Field and pot experiments with two nitrogen levels were conducted using a randomized design with three biological replicates to evaluate the effects of high nitrogen application on culm mechanical properties, secondary cell wall development, and associated metabolic pathways. Mechanical measurements and microscopic analysis revealed that high nitrogen significantly reduced culm rigidity and impaired sclerenchyma development. To investigate the underlying mechanisms, integrated transcriptomic and proteomic analyses were performed on developing internodes. Differentially expressed genes and proteins were predominantly enriched in carbohydrate metabolism and phenylpropanoid biosynthesis pathways. Notably, key enzymes involved in lignin biosynthesis were consistently downregulated at the protein level under high-nitrogen conditions. In contrast, genes and proteins related to cellulose and hemicellulose biosynthesis exhibited transient inhibition at early stages followed by recovery or upregulation at later stages. Consistent with these findings, histochemical staining and quantitative assays demonstrated a significant reduction (14–16%) in lignin content in the fourth internode, whereas cellulose content showed no substantial change. Furthermore, lignin biosynthetic genes (OsCAD2, Os4CL3, and OsCOMT) were persistently suppressed during critical stages of secondary wall formation, while cellulose synthase genes (OsCESA4, OsCESA7, and OsCESA9) displayed more variable and less sustained expression patterns. Collectively, these results demonstrate that excessive nitrogen application weakens rice culms primarily by inhibiting lignin accumulation rather than cellulose deposition. The preferential suppression of the phenylpropanoid pathway and disruption of secondary cell wall formation provide a mechanistic basis for nitrogen-induced lodging susceptibility in rice. Full article

Background/Objectives: Among cotton species, Gossypium barbadense produces the strongest fibers. Examining cytoskeletal dynamics in single epidermal cells of G. barbadense ovules offers a direct approach to investigating fiber quality. Microtubules are major cytoskeletal components whose organization and dynamics are precisely regulated by microtubule-associated proteins (MAPs). However, information on the TPX2 family remains limited, and characterizing its features in G. barbadense is critical to clarifying the role of TPX2 family members in fiber strength formation. Methods: Using the Arabidopsis thaliana TPX2 sequence as a reference, 40, 49, 26, and 26 TPX2 family members were identified in the genomes of G. barbadense, Gossypium hirsutum, Gossypium arboreum, and Gossypium raimondii, respectively. We further analyzed the expression pattern of GbTPX2-35 and validated its function via virus-induced gene silencing (VIGS). Results: In G. barbadense, GbTPX2-35 (Gbar_D11G59825.1) was significantly upregulated in fiber samples of the parental lines at 25 days post-anthesis, and this expression pattern was further validated in G. barbadense lines with extreme fiber strength phenotypes. Next, VIGS-mediated silencing of GbTPX2-35 downregulated the transcript levels of cellulose synthase and microtubule-related protein genes, a finding further validated by mature fiber strength phenotypic data. Conclusions: This study preliminarily validated a pathway in which GbTPX2-35 regulates fiber strength by coordinating cellulose biosynthesis with microtubule cytoskeleton dynamics, providing valuable candidate genes and theoretical support for molecular breeding of high-strength cotton fibers. Full article

Phytophthora infestans, a devastating oomycete pathogen responsible for late blight in solanaceous crops, relies on cellulose synthase (CesA) complexes for cell wall biosynthesis and virulence. Unlike plant CesAs that form homomeric trimers, oomycete CesA complexes are hypothesized to assemble as heteromeric units, yet their structural organization remains poorly defined. Here, we employed AlphaFold-Multimer and molecular docking to resolve the structural assembly of the PiCesA1–PiCesA2–PiCesA4 heterotrimer in P. infestans and identify potential ligand-binding sites for targeted inhibition. Structural modeling revealed a conserved transmembrane architecture combined with a distinctive cytosolic organization, in which N-terminal pleckstrin homology domains play a central role in heteromeric assembly. AlphaFold-Multimer consistently predicted a stable heterotrimer stabilized by cyclic interactions between pleckstrin homology domains and glycosyltransferase-A domains, forming an extensive interface network that is spatially segregated from the conserved UDP-glucose–binding catalytic core. Structure-guided docking identified potential ligands targeting pleckstrin homology–glycosyltransferase interface regions. Notably, these sites are absent or structurally divergent in plant cellulose synthases, underscoring their potential for pathogen-selective targeting. This work advances mechanistic understanding of cellulose biosynthesis in filamentous pathogens and proposes new avenues for selective disease control in agriculture. Full article

Bacterial cellulose hydrogels (BCHs) are characterized as exopolysaccharides of glucose polymers consisting of β–1–4–glycosidic linkage with various degrees of polymerization which are synthesized by bacteria. There is a paucity of information on the isolation and characterization of a BCH producer isolate from Nigeria. The study, therefore, aimed to characterize a new Acetobacter species that had previously been confirmed to produce BCH. The BCH-producing isolate was characterized by PCR amplification of the full-length 16S rRNA gene, as well as whole-genome sequencing analysis. The whole-genome sequence of the isolate was determined using the Illumina next-generation sequencing (NGS) platform, with downstream analysis of genomic reads through the metaWRAP pipeline. The BCH producer isolate was identified to be Acetobacter orientalis strain Zaria-B1, based on sequence identity with the reference Acetobacter orientalis strain VVS. Based on its annotated genome, the isolate had an approximate genomic size of 3.1 Mbp, 45 total RNAs, a GC content of 52.5%, 3046 total protein-encoding genes, an N50 of 253,774 bp, and an L50 of 4, as well as 30 contigs. The nucleotide BLAST of the cellulose synthase gene sequence confirmed the bin to be Acetobacter orientalis. The whole-genome characterization alongside the 16S rRNA genotyping confirmed the BCH-producing isolate to be Acetobacter orientalis. Full article

The BTB/POZ protein family is widely distributed across the biological kingdom, and its various subfamilies perform diverse physiological functions, including regulating plant growth and development, defending against pathogen invasion, participating in metabolic regulation, and responding to abiotic stresses. However, the functional roles of BTB genes in wood formation remain largely unknown. In this study, a total of 103 BTB genes were identified in Populus trichocarpa. Expression pattern analysis and β-glucuronidase (GUS) staining revealed that PtrBTB82 was predominantly expressed in the xylem. Overexpression of PtrBTB82 in P. trichocarpa significantly reduced cambial activity, resulted in a narrower xylem, and altered the chemical composition of the secondary cell wall, suggesting that PtrBTB82 plays the roles in wood formation. Quantitative real-time PCR (RT-qPCR) analysis showed that overexpression of PtrBTB82 suppressed the expression of genes related to the WUSCHEL-related pathway and plant hormone signaling, which may underlie the reduced cambial activity and inhibited xylem development. Moreover, genes associated with lignin biosynthesis (PtrPALs, PtrC4H1, Ptr4CL and PtrCAD1) were upregulated, while secondary wall cellulose synthase genes (PtrCESA7A/B and PtrCESA8A) were markedly downregulated in the overexpression lines, likely contributing to the altered chemical composition of the wood. Collectively, this study provides new insights into the role of PtrBTBs in wood formation, thereby revealing the functional diversity of the BTB family in plants. Full article

The cellulose synthase (CS) superfamily, comprising the cellulose synthase (CESA) and cellulose synthase-like (CSL) families, plays crucial roles in plant response to abiotic stresses, growth and development. However, there are few reports on the biological functions of CSs in soybean. In this study, 80 soybean CS members were identified and classified into seven subfamilies. Collinearity analyses revealed that the segmental duplication is likely the primary driver for the expansion of CS superfamily in soybean. The abundant stress-responsive and growth-related cis-acting elements in the promoter regions of soybean CS genes suggest their potential functions. Notably, GmCESA1 exhibited significantly higher expression levels in drought-tolerant soybean under drought stress. Soybean plants with lower GmCESA1 expression via virus-induced gene silencing (VIGS-GmCESA1) were less drought-tolerant than the control plants (VIGS-EV), showing reduced relative water content and dry weight than VIGS-EV under drought stress. Furthermore, VIGS-GmCESA1 soybean plants displayed reduced plant height under both well-watered and drought-stressed conditions. Our findings highlight that GmCESA1 has pleiotropic functions in regulating both drought tolerance and growth in soybean, contributing to our knowledge on CS and providing a valuable gene to breed drought-tolerant soybean in the future. Full article

Cellulose is the primary component of plant cell walls, and its content is linked to the strength of plant stems. The cellulose synthase genes (CesA) are crucial for regulating cellulose biosynthesis. To examine the characteristics and functions of CesA genes in sugarcane, our study conducted a genome-wide analysis of the Saccharum officinarum LA-Purple genome. The results identified 10 CesA genes in the S. officinarum genome, which could be grouped into six categories. SoCesA10, SoCesA11, and SoCesA12 are clustered within the same subclass as genes involved in secondary cell wall synthesis in rice and Arabidopsis. Further transcriptome analysis of stems at different stages and sections showed that SoCesA10, SoCesA11, and SoCesA12 were highly expressed during mature stages. Among these, SoCesA10 and SoCesA11 showed differences in expression between species and organs. Their gene functions were also validated in rice, revealing that the expression of SoCesA10 and SoCesA11 was positively correlated with cellulose content. In summary, this study identified key cellulose biosynthesis genes, SoCesA10 and SoCesA11, in sugarcane and preliminarily confirmed their functions in rice, providing a foundation for breeding sugarcane with improved lodging resistance. Full article

Background: Seed shattering enhances ecological adaptation in perennial grasses but severely limits harvestable seed yield in forage crops. Psathyrostachys juncea is an important perennial forage species in arid and cold regions, yet the genetic basis of its seed shattering remains largely unknown. Here we asked which genomic regions and biological pathways underlie natural variation in seed shattering in P. juncea, and whether cellulose synthase (CESA)-mediated cell-wall formation contributes to abscission-zone strength. Results: We evaluated seed shattering in a diverse association panel of P. juncea across four environment–-year combinations and performed a genome-wide association study (GWAS) using genotyping-by-sequencing single-nucleotide polymorphism (SNP) markers. The analysis identified 36 significant SNP loci distributed on multiple chromosomes, consistent with a highly polygenic and environment-responsive architecture. Candidate-gene annotation highlighted pathways related to cell-wall biosynthesis, hormone signaling and sugar transport. Notably, in the BT23SHT environment a cluster of association signals on chromosome 3D co-localized with several genes annotated as cellulose synthase (CESA). Abscission-zone transcriptome profiling and qRT-PCR at 7, 14, 21 and 28 days after heading revealed that CESA genes, including TraesCS3D02G010100.1 located near the lead SNP Chr3D_3539055, showed higher early expression in low-shattering lines and a decline toward baseline in high-shattering lines. Comparative analyses placed P. juncea CESA proteins within a broadly conserved but lineage-divergent framework among grasses. Conclusion: Together, these results define the genetic landscape of seed shattering in P. juncea and nominate cellulose-biosynthetic genes on chromosome 3D as promising targets for marker-assisted selection of low-shattering, high-seed-yield forage cultivars. Full article

Lenticel spots (fruit dots) on pear peel strongly influence consumer preference and market price, yet the regulatory networks underlying their lignin/cellulose deposition remain elusive. Here, we integrated electron microscopy, metabolomics, and RNA-seq across three developmental stages (30, 40, and 60 d after full bloom, DAFB) in the pear cultivar ‘Dangshansuli’ (SL) and its bud-sport ‘Dangshanxisu’ (XS). XS exhibited fewer lenticel spots and lower lignin, cellulose, and hemicellulose contents than SL, with the critical onset of lignin and cellulose accumulation detected between 40 and 60 DAFB. Metabolome-wide analysis detected five differentially accumulated lignin monomers, while transcriptome profiling revealed 79 differentially expressed genes (padj ≤ 0.05, |log₂FC| ≥ 1) enriched in phenylpropanoid and cellulose-synthase pathways. Weighted gene co-expression network analysis (WGCNA) uncovered two modules (|r| > 0.8, p < 0.05) positively correlated with lignin and cellulose content, harboring 11 structural genes (4CL, F5H, CCR, COMT, PRX/POD and CESA isoforms) and five transcription-factor families (MYB, NAC, AP2/ERF, WRKY, bHLH). RT-qPCR validated the coordinated down-regulation of these genes in XS relative to SL. Our results decipher the gene–metabolite circuitry driving lenticel lignification in pear, providing molecular targets for breeding peel-perfect cultivars and for cultural practices that minimize superficial blemishes. Full article

Lamiophlomis rotata (Benth.) Kudo is a typical alpine medicinal plant. However, the mechanism underlying its adaptation to high altitudes remains incompletely understood. In this study, we integrated transcriptome and metabolome analyses. Specifically, we used third-generation sequencing for building a reference transcriptome and second-generation sequencing for differential gene expression analysis. Our findings revealed that the activation of the hydrogen sulfide signaling pathway and the reprogramming of amino acid metabolism are probable adaptation mechanisms. Different from previous reports, the hydrogen sulfide signaling may regulate the activity of cellulose synthase in addition to enhancement of antioxidant capacity and accumulation of osmolytes. By altering the agronomic traits of plants in a cell wall remodeling-dependent manner, it enables L. rotata to adapt to alpine stress. The accumulated amino acids not only store energy-efficient organic nitrogen as precursors for the synthesis of secondary metabolites but also act as signaling molecules to activate defense responses. Additionally, we propose a potential link between the hydrogen sulfide signaling pathway and amino acid metabolism. Overall, this study systematically explores the adaptation mechanism of L. rotata to high-altitude environments, offering a novel perspective for understanding the growth, development, stress responses, and secondary metabolic processes of alpine plants. Full article

Antarctic microorganisms have developed extraordinary strategies for adaptation. They have also demonstrated the ability to produce various biopolymers in response to environmental stress. The demand for biopolymers is constantly increasing and is expected to grow further. Among emerging biomaterials, bacterial cellulose (BC) is generating significant interest due to its unique characteristics that distinguish it from plant-based cellulose. BC exhibits higher purity, water-holding capacity, and tensile strength compared to its plant-based counterpart. Furthermore, BC can be obtained through environmentally friendly protocols. Several bacterial strains have already been identified as cellulose producers, including Komagataeibacter xylinus. In this study, a marine bacterial strain named Pseudomonas sp. ef1, isolated from a consortium associated with the Antarctic ciliate Euplotes focardii, was tested for cellulose production. We found that this Antarctic Pseudomonas can produce BC in conditions that appear unique to this bacterial strain. Furthermore, the final BC product is structurally different from that obtained from the well-known BC producer Komagataeibacter xylinus. Additionally, a putative cellulose synthase was identified from the Pseudomonas sp. ef1 genome, exhibiting unique characteristics that may account for the unique BC production capability of this Antarctic marine Pseudomonas. The versatility of BC opens numerous applications, including in papermaking, food, pharmaceutical, and biomedical sectors. Full article