Search Results (26)

Understanding whether long-term vascular cambium vitality in ancient trees reflects progressive decline or adaptive reprogramming is central to grasping woody plant longevity. We performed an integrative analysis of functional traits, transcriptome profiles, and metabolomic landscapes of cambial zone enriched from 80-, 500-, and 1000-year-old Styphnolobium japonicum trees. With increasing tree age, the vascular cambium showed fewer cell layers, reduced thickness, and lower auxin, gibberellin, and IAA/ABA ratios, whereas bark thickness, malondialdehyde, abscisic acid, jasmonic acid, and salicylic acid contents increased. Transcriptomic and metabolomic analyses revealed that differentially expressed genes and metabolites were primarily enriched in the cell cycle, phytohormone signaling, and phenylpropanoid biosynthesis pathways. Specifically, genes associated with cell division were down-regulated in millennial trees, whereas phenolic acids, flavonoids, and lignin-related metabolites significantly accumulated. Piecewise structural equation modeling suggested associations among tree age, transcription factors, structural genes, metabolites, and cambial functional traits. These results indicate that cambial senescence is not a simple linear decay but a highly coordinated remodeling process, providing crucial evidence for delayed senescence in long-lived woody species. Full article

Sunflower (Helianthus annuus) is highly susceptible to infection by the root parasitic plant Orobanche cumana during its growth. In establishing connections with the sunflower root system, O. cumana induces the hydrolysis and remodeling of the host cell wall. Xyloglucan endotransglucosylase/hydrolase (XTH), a member of glycoside hydrolase family 16 (GH16), is a key enzyme involved in the hydrolysis and synthesis of xyloglucan, playing a critical role in cell wall modification and reconstruction. However, the involvement of XTH families in the interaction between sunflower and O. cumana remains unclear. In this study, we showed that the expression level of HaXTH2 was upregulated in sunflowers following O. cumana infection. Overexpression of HaXTH2 loosens host primary cell walls and represses lignin-based defense responses at the early infection stage, thereby facilitating haustorial penetration across cortical tissues and xylem bridge formation to support normal parasitism of O. cumana. Functional analysis revealed that HaXTH2 and its homolog, HaXTH2-1, facilitate O. cumana infection, whereas OcXTH2, an O. cumana homolog, suppresses this process. Furthermore, HaXTH2, HaXTH2-1, and OcXTH2 are localized to the cell wall. Domain truncation analysis revealed that the GH16 domain alone from HaXTH2 and HaXTH2-1 enhance parasitic susceptibility, while the xyloglucan endotransglycosylase C-terminal domain (XET_C) domain does not. Mutation analysis identified Y20 in HaXTH2 and H96 in HaXTH2-1 as key amino acid sites regulating O. cumana parasitism. This study expands our understanding of the functions of XTHs in plant–plant interactions and provides a theoretical basis for further development of O. cumana-resistant sunflower cultivars. Full article

The extracellular matrix (ECM) provides a dynamic microenvironment that regulates cell proliferation, migration, and tissue remodeling during wound healing. However, replicating the structural and functional complexity and ECM heterogeneity of native skin ECM remains challenging with conventional single-material hydrogels. Recent advances in multimaterial 3D bioprinting have enabled the spatial integration of diverse biomaterials within a single construct. Lignocellulose has attracted increasing attention as a promising biomaterial for recreating key structural features of the native ECM because of its fibrous architecture, mechanical strength, and biocompatibility. This review offers a comprehensive and integrated perspective on the use of lignocellulose-based multimaterial printing to recreate ECM-mimicking architectures, an underexplored area at the intersection of biomaterials and biofabrication. The roles of cellulose, hemicellulose, and lignin in printability, scaffold stability, porosity, bioactivity, and wound-healing performance are discussed. Representative studies have demonstrated that lignocellulose-based multimaterial bioinks provide porous architectures that support cell adhesion, proliferation, and tissue regeneration. These benefits are accompanied by improved mechanical performance, as cellulose nanofibers exhibit elastic moduli exceeding 100 GPa, and lignin-containing hydrogels have achieved compressive moduli of up to 135 kPa. Such mechanical advantages make lignocellulosic materials particularly attractive for fabricating ECM-mimicking scaffolds that require long-term structural integrity. Finally, key design considerations and current limitations associated with lignocellulose-based multimaterial bioprinting are critically discussed. A framework for the rational design of lignocellulose-based multimaterial bioinks is presented, together with future directions toward gradient and adaptive scaffolds, smart wound dressings, and advanced wound-healing applications. Full article

While L-tryptophan is a precursor of plant growth regulators, its effects on secondary metabolism, amino acid profile and cell wall organization in flax callus remain underexplored. This study aimed to optimize flax callus shaken cultures and evaluate the impact of L-tryptophan (0.1 mM and 1 mM) on structural properties of plant cell walls in tested callus using Fourier transform infrared spectroscopy. The impact of L-tryptophan on callus proliferation and metabolism was also determined, because amino acids (among them L-tryptophan) can promote the growth of callus. The results showed that 1 mM L-tryptophan is an effective elicitor, which stimulates flax callus to accumulate larger amounts of bioactive compounds, especially carotenoids and polyphenols, than control callus cultured without L-tryptophan. A lower concentration of L-tryptophan (0.1 mM) slightly improved the level of determined secondary metabolites (except flavonoids). The effect of L-tryptophan on polymers in plant cell walls was investigated. The data confirm that the plant cell wall is a dynamic structure, capable of remodelling in response to growth conditions and external agents. L-tryptophan (0.1 and 1 mM) reduced cellulose levels and induced structural changes in cellulose compared to the untreated control. The structural analyses also suggested a decrease in lignin level and increase in pectin amounts in flax callus after tryptophan addition in comparison to control callus. The results may reflect the relationship between tryptophan and auxins (which are derived from tryptophan) and confirm the role of these metabolites in shaping the structure of the plant cell wall. In fact, an increase in tryptophan level was confirmed in flax callus in tested experimental conditions (supplementation of cultures with both doses of L-tryptophan). These findings have practical significance, because L-tryptophan is also used as a fertilizer or component of fertilizers in plant cultivation. Full article

Soil salinity represents a significant abiotic constraint limiting the productivity and geographical expansion of rapeseed (Brassica napus L.), yet the coordination among the signaling, hormonal, metabolic, and regulatory layers underlying salt tolerance remains incompletely understood. This study elucidates the physiological, biochemical, and transcriptomic responses of B. napus inbred line 383-5 to moderate salt stress (100 mM NaCl at day 10), identifying key lncRNA–mRNA regulatory networks. Salt stress induced pronounced, dose-dependent growth inhibition, oxidative damage, and osmotic adjustment, accompanied by extensive transcriptional reprogramming. Genome-wide analyses identified 6215 differentially expressed protein-coding genes and 941 salt-responsive long non-coding RNAs (lncRNAs), revealing coordinated regulation of ion transport, redox homeostasis, phytohormone signaling, and secondary metabolism. Functional enrichment analyses highlighted the central involvement of abscisic acid and ethylene signaling pathways, MAPK cascades, membrane transporters, and antioxidant systems. Notably, salt stress strongly activated the phenylpropanoid and lignin biosynthesis pathways, suggesting reinforced cell wall remodeling and enhanced oxidative stress mitigation. Integration of lncRNA–mRNA regulatory networks further indicated that non-coding transcripts act as important modulators linking hormone signaling, redox balance, and metabolic adaptation. Collectively, these results reveal a multilayered and tightly synchronized regulatory framework underlying salinity tolerance in B. napus and provide valuable molecular targets for the genetic improvement of salt-resilient rapeseed cultivars. Full article

Dodder (Cuscuta campestris) is a parasitic plant that causes severe economic losses to crops such as mung bean (Vigna radiata), although some species, including tomato (Solanum lycopersicum), exhibit varying degrees of resistance. Dodder parasitism begins with the development of the haustorium, whose endophytic primordium undergoes intrusive growth to penetrate host tissues. While the cell walls of endophytic cells are essential for invasion, the sequential changes occurring in these cell walls are not fully understood. This study aims to characterize cell wall modifications in Cuscuta campestris haustoria during parasitism of a susceptible host (Vigna radiata) and a resistant host (Solanum lycopersicum ‘Minibel’), using histochemical and immunohistochemical approaches focused on homogalacturonan (HG) and arabinogalactan proteins (AGPs). In both hosts, AGPs and HG (predominantly in their demethylesterified form) increased in the host-facing epidermal walls, the aligned file cells of the haustoria, and the boundary layer surrounding the haustorial cone. The boundary layer was enriched in AGPs and initially showed massive HG deposition, later incorporating lignin and callose. In tomato, lignin-based resistance was associated with the outermost cortical cells and did not substantially affect the overall dynamics of the dodder cell walls. These findings highlight the central role of coordinated cell wall remodeling in dodder invasion and reveal broadly similar developmental trajectories of HG and AGPs in haustoria formed on susceptible and resistant hosts. Full article

Soil heavy metal (HM) pollution poses a severe threat to ecological security and human health. Selenium (Se) is an essential trace element for the human body and can regulate crop growth and development as well as HM uptake in HM-contaminated soils. The regulatory mechanisms of Se on HMs are mainly reflected in four aspects: Geochemical immobilization promotes the formation of metal selenide precipitates and the adsorption of HMs by soil colloids by regulating the rhizosphere redox potential (Eh) and pH value. Rhizosphere microbial remodeling drives the enrichment of functional microorganisms such as Se redox bacteria, plant growth-promoting rhizobacteria (PGPR), and arbuscular mycorrhizal fungi (AMF) through the dual selective pressure of Se toxicity and root exudates, in order to synergistically realize Se speciation transformation and HM adsorption/chelation. Root barrier reinforcement constructs physical and chemical dual defense barriers by inducing the formation of iron plaques on the root surface, remodeling root morphology and strengthening cell wall components such as lignin and polysaccharides. Intracellular transport regulation down-regulates the genes encoding HM uptake transporters, up-regulates the genes encoding HM efflux proteins, and promotes the synthesis of phytochelatins (PCs) to form HM complexes and lastly realizes vacuolar sequestration. Finally, we summarize current research gaps in the interaction mechanisms of different Se species, precise application strategies, and long-term environmental risk assessment, providing a theoretical basis and technical outlook for the green remediation of HM-contaminated farmlands and Se biofortification of crops. Full article

Pinus massoniana, a critically important afforestation species in subtropical China, shows severe adventitious rooting recalcitrance linked to endogenous gibberellin (GA) dysregulation. Our study reveals a GA₄-mediated regulatory network that coordinates hormonal crosstalk, redox homeostasis, and cell wall remodeling. Treatment with the GA biosynthesis inhibitor paclobutrazol (PBZ, 100 mg·L⁻¹) shortened rooting time by 32.5% and increased rooting success by 79.5%. We found that PBZ redirected GA flux by upregulating GA₃-oxidase (GA₃OX), leading to GA₄ accumulation. However, elevated GA₄ levels impaired root development by triggering suberization through ferulic acid (FA)-mediated redox imbalance. Application of GA₄ (100 mg·L⁻¹) reduced caffeoyl alcohol content by 54.4% but increased FA and caffeic acid levels 2.4–3.9-fold, shifting lignin precursors toward suberin biosynthesis. FA modulated H₂O₂ flux in a dose-dependent manner: 200 mg·L⁻¹ optimized redox homeostasis (93.7% lower H₂O₂ influx), whereas 1000 mg·L⁻¹ suppressed mitosis. The combination of PBZ (100 mg·L⁻¹) and FA (200 mg·L⁻¹) synergistically enhanced rooting success by 34.4% and achieved 95.8% field survival after two years (vs. 68.5% in controls), challenging the traditional view that lignification alone limits rooting in woody plants. This work provides the first evidence that the GA₄-FA axis controls adventitious root formation in conifers via a Reactive oxygen species (ROS)-dependent switch between suberin and lignin metabolism, offering new strategies to overcome rooting barriers. The PBZ + FA protocol enables scalable clonal propagation of recalcitrant conifers, with potential applications in molecular breeding and forest restoration. Full article

Halophytes such as Salicornia europaea rely on biochemical and structural mechanisms to survive in saline environments. This study aimed to evaluate oxidative stress and structural defense responses in four inland populations—Poland (Inowrocław, Ciechocinek), Germany (Salzgraben-Salzdahlum, Salz), and Soltauquelle (Soltq)—subjected to 0, 200, 400, and 1000 mM NaCl, using non-destructive, image-based approaches. Lipid peroxidation was assessed via malondialdehyde (MDA) detected with Schiff’s reagent, and hydrogen peroxide (H₂O₂) accumulation was visualized with 3,3′-diaminobenzidine (DAB). Roots and shoots were analyzed through colour image analysis and quantified using a computer vision system (CVS). MDA accumulation revealed population-specific differences, with Salz tending to exhibit lower peroxidation, characterized by lower L* ≈ 42–43 and higher b* ≈ 37–18 in shoots at 200–400 mM, which may reflect a potentially more effective salt-management strategy. Although H₂O₂ responses deviated from a direct salinity-dependent trend, particularly in the tolerant Salz and Soltq populations, both approaches effectively tracked population-specific adaptation, with German populations displaying detectable basal H₂O₂ levels, consistent with its multifunctional signalling role in salt management and growth regulation. Structural defences were further explored through histochemical mapping and image analysis of pectin and lignin distribution, which revealed population-specific patterns consistent with cell wall remodelling under stress. Non-destructive, image-based methods proved effective for detecting oxidative and structural responses in halophytes. Such a non-destructive, cost-efficient, and reproducible approach can accelerate the identification of salt-tolerant ecotypes for saline agriculture and reinforce S. europaea as a model species for elucidating salt-tolerance mechanisms. Full article

The cell wall, acting as the first line of defense against aluminum (Al) toxicity, is the primary cellular structure that encounters and perceives Al³⁺. Xyloglucan endotransglucosylase/hydrolase (XTH) plays a pivotal role in mediating cell wall remodeling, a critical mechanism for Al toxicity tolerance. In our previous studies, the candidate gene BnaXTH22 was identified through GWAS and RNA-seq analyses. Under Al toxicity stress, overexpression lines (OEs) exhibited a significant increase in the relative elongation of taproots (9.44–13.32%) and total root length (8.15–12.89%) compared to the wild type (WT). Following Al treatment, OEs displayed reduced MDA content and lower relative electrical conductivity, alongside a significantly higher root activity than WT. Transcriptomic analysis revealed that differentially expressed genes in OE under Al toxicity were predominantly enriched in stress-related biological processes, including phenylpropanoid metabolism, fatty acid biosynthesis, and lignin biosynthesis. These results suggest that BnaXTH22 overexpression could enhance Al toxicity tolerance in rapeseed, potentially by modulating cell wall synthesis to bolster plant resistance. Full article

The novel hydro-electro hybrid priming (HEHP) technique, which synergistically combines controlled hydration and electrostatic field application, represents an innovative chemical-free approach to improve seed germination synchrony. However, the regulatory mechanism of HEHP on cell wall remodeling during post-imbibition remains unclear. Here, we demonstrate that HEHP accelerates carrot (Daucus carota L.) seed germination by synchronizing cell wall hydrolysis and synthesis pathways. Comparative transcriptomics revealed 4591 differentially expressed genes (DEGs) between HEHP-treated and untreated seeds, with significant enrichment in cell wall organization (GO terms) and phenylpropanoid biosynthesis (KEGG pathway). HEHP significantly induced the expression of expansin (EXP), hydrolases (xyloglucan endotransglucosylase (XET), pectinesterase (PE), and phenylalanine ammonia lyase (PAE)), and synthases (cellulose synthase (CesA)), reducing endosperm rupture force considerably at S20 compared to hydropriming (HYD). Enzymatic assays confirmed earlier activity peaks for XET and PE in HEHP, correlating with the sustained expression of key genes. Notably, HEHP pre-activated germination-related metabolism, evidenced by fewer post-imbibition DEGs, and synchronized lignin deposition via transient phenylalanine ammonia lyase (PAL) and 4-coumarate/CoA ligase (4CL) activation. These synergies enabled faster radicle emergence than HYD. Our findings reveal that HEHP optimizes cell wall loosening–reinforcement dynamics through transcriptional priming, offering a tailored solution for mechanized sowing in Apiaceae crops. Full article

Background: Plants face a wide range of environmental stresses that disrupt growth and productivity. To survive and adapt, they undergo complex metabolic reprogramming by redirecting carbon and nitrogen fluxes toward the biosynthesis of protective secondary metabolites such as phenylpropanoids, flavonoids, and lignin. Recent research has revealed that these stress-induced metabolic processes are tightly regulated by epigenetic mechanisms, including DNA methylation, histone modifications, chromatin remodeling, and non-coding RNAs. Methods: This review synthesizes current findings from studies on both model and crop plants, examining the roles of key epigenetic regulators in controlling secondary metabolism under stress. Special focus is placed on dynamic changes in DNA methylation, histone acetylation, and the action of small RNAs such as siRNAs and miRNAs in transcriptional and post-transcriptional regulation. Results: Evidence indicates that stress triggers rapid and reversible epigenetic modifications that modulate gene expression linked to secondary metabolic pathways. These modifications not only facilitate immediate metabolic responses but can also contribute to stress memory. In some cases, this memory is retained and transmitted to the next generation, influencing progeny stress responses. However, critical knowledge gaps remain, particularly concerning the temporal dynamics, tissue specificity, and long-term stability of these epigenetic marks in crops. Conclusions: Understanding how epigenetic regulation governs secondary metabolite production offers promising avenues to enhance crop resilience and productivity in the context of climate change. Future research should prioritize dissecting the stability and heritability of these modifications to support the development of epigenetically informed breeding strategies. Full article

The accumulation of aniline in the natural environment poses a potential threat to crops, and thus, investigating the effects of aniline on plants holds practical implications for agricultural engineering and its affiliated industries. This study combined physiological, transcriptomic, and metabolomic methods to investigate the growth status and molecular-level response mechanisms of rice under stress from varying concentrations of aniline. At a concentration of 1 mg/L, aniline exhibited a slight growth-promoting effect on rice. However, higher concentrations of aniline significantly inhibited rice growth and even caused notable damage to the rice seedlings. Physiological data indicated that under aniline stress, the membrane of rice underwent oxidative damage. Furthermore, when the concentration of aniline was excessively high, the cells suffered severe damage, resulting in the inhibition of antioxidant enzyme synthesis and activity. Transcriptomic and metabolomic analyses indicated that the phenylpropanoid biosynthesis pathway became quite active under aniline stress, with alterations in various enzymes and metabolites related to lignin synthesis. In addition to the phenylpropanoid biosynthesis pathway, amino acid metabolism, lipid metabolism, and purine metabolism were also critical pathways related to rice’s response to aniline stress. Significant changes occurred in the expression levels of multiple genes (e.g., PRX, C4H, GST, and ilvH, among others) associated with functions such as antioxidant activity, membrane remodeling, signal transduction, and nitrogen supply. Similarly, notable alterations were observed in the accumulation of various metabolites (for instance, glutamic acid, phosphatidic acid, phosphatidylglycerol, and asparagine, etc.) related to these functions. Our research findings have unveiled the potential of compounds such as phenylpropanoids and amino acids in assisting rice to cope with aniline stress. A more in-depth and detailed exploration of the specific mechanisms by which these substances function in the process of plant resistance to aniline stress (for instance, utilizing carbon-14 isotope tracing to monitor the metabolic pathway of aniline within plants) will facilitate the cultivation of plant varieties that are resistant to aniline. This will undoubtedly benefit activities such as ensuring food production and quality in aniline-contaminated environments, as well as utilizing plants for the remediation of aniline-polluted environments. Full article

Plant height represents a pivotal agronomic trait for the genetic enhancement of crops. The plant cell wall, being a dynamic entity, is crucial in determining plant stature; however, the regulatory mechanisms underlying cell wall remodeling remain inadequately elucidated. This study demonstrates that the application of gibberellin 3 (GA3) enhances both plant height and cell wall remodeling in tomato (Solanum lycopersicum L.) plants. RNA sequencing (RNA-seq) results of GA3 treatment showed that the DEGs were mostly enriched for cell wall-related pathways; specifically, GA3 treatment elicited the expression of the cell wall-associated gene XYLOGLUCAN ENDOTRANSGLUCOSYLASE/HYDROLASE 19 (SlXTH19), whose overexpression resulted in increased plant height. Comparative analyses revealed that SlXTH19-overexpressing lines exhibited larger cell dimensions and increased XTH activity, along with higher contents of lignin, cellulose, and hemicellulose, thereby underscoring the gene’s role in maintaining cell wall integrity. Conversely, treatments with ethephon (ETH) and 1-Naphthaleneacetic acid (NAA) led to suppressed plant height and reduced SlXTH19 expression. Collectively, these findings illuminate a competitive interplay between GA and ethylene/auxin signaling pathways in regulating cell wall remodeling via SlXTH19 activation, ultimately influencing tomato plant height. Full article

A novel MADS-box transcription factor from Pinus radiata D. Don was characterized. PrMADS11 encodes a protein of 165 amino acids for a MADS-box transcription factor belonging to group II, related to the MIKC protein structure. PrMADS11 was differentially expressed in the stems of pine trees in response to 45° inclination at early times (1 h). Arabidopsis thaliana was stably transformed with a 35S::PrMADS11 construct in an effort to identify the putative targets of PrMADS11. A massive transcriptome analysis revealed 947 differentially expressed genes: 498 genes were up-regulated, and 449 genes were down-regulated due to the over-expression of PrMADS11. The gene ontology analysis highlighted a cell wall remodeling function among the differentially expressed genes, suggesting the active participation of cell wall modification required during the response to vertical stem loss. In addition, the phenylpropanoid pathway was also indicated as a PrMADS11 target, displaying a marked increment in the expression of the genes driven to the biosynthesis of monolignols. The EMSA assays confirmed that PrMADS11 interacts with CArG-box sequences. This TF modulates the gene expression of several molecular pathways, including other TFs, as well as the genes involved in cell wall remodeling. The increment in the lignin content and the genes involved in cell wall dynamics could be an indication of the key role of PrMADS11 in the response to trunk inclination. Full article