Abstract Permafrost soils constitute a large part of the terrestrial carbon pool that is vulnerable to future climate warming. Continued warming of the low Arctic is also leading to the encroachment of large shrubs and trees into tundra ecosystems with effects on microbial community composition, organic matter cycling and physical soil parameters. To date it is still largely unknown how such vegetation shifts affect soil organic matter cycling in permafrost soils on short and long timescales. Here, we investigated differences in soil organic matter properties under graminoid tussock ( Eriophorum vaginatum ), birch shrub ( Betula glandulosa ), spruce tree ( Picea mariana ) and alder shrub ( Alnus viridis ) vegetation by density fractionation and subsequent measurements of organic carbon, total nitrogen, δ 13 C, and lignin phenol biomarker contents. Particulate organic matter constituted 1.3–11.3% of soil weight and stored between 29 and 89% of the total soil lignin, 12–60% of organic carbon and 6–40% of total nitrogen. The contribution of particulate organic matter generally decreased with soil depth. Soils under Alnus viridis showed significantly higher amounts of particulate organic matter and stored more lignin, organic carbon and total nitrogen in particulate form in all soil depths. Sites dominated by Eriophorum vaginatum exhibited higher lignin content and lower degradation state in the subsoil, which was associated with water saturation and low active layer depth. We conclude that the effect of vegetation changes on soil organic matter cycling is dependent on plant species with the encroachment of Alnus viridis shrubs potentially increasing the deposition of particulate organic matter into permafrost soils.

Abstract Insect-associated microorganisms play crucial roles in host plant adaptation. Although oral microbiota are the primary interface with ingested plant material, their diversity, function, and ecological relationship with insect performance remain poorly understood. Here, we investigated the diversity and function of the oral microbiota in two generalist lepidopteran pests (Spodoptera litura and S. frugiperda) feeding across three host plants (bok choy, peanut, and maize). Plant species significantly influenced the diversity and composition of oral microbiota in both S. litura and S. frugiperda. Oral microbial communities from insects feeding on bok choy exhibited significantly higher Sobs richness and Shannon diversity compared to those with peanut or maize plants. Community-level analysis revealed overlapping enriched oral taxa, including Brevibacterium, Staphylococcus, Microbacterium, Allorhizobium-Neorhizobium-Pararhizobium-Rhizobium, Brachybacterium, and Rhodococcus of both insect species when consuming bok choy. In contrast, they accumulated distinct bacterial taxa emerged when feeding on peanut and maize. Microbial ligninolysis capacity within the oral microbiota showed positive associations with leaf lignin content and herbivore performance. This functional trait primarily associated with Brevibacterium and Rhodococcus taxa. Accordingly, two isolated strains, Brevibacterium sedimins OS20 and Rhodococcus sp. OS5 demonstrated effective lignin degradation capacity, achieving 41.01% and 17.62% lignin loss in litter, respectively after 60 days in microcosm experiments. Overall, host plants shape the diversity and composition of insect oral microbiota. Crucially, microbial ligninolysis capacity and leaf lignin content positively correlated with herbivore performance. This study provides novel insights into the function of oral microbiota in plant-insect interactions, potentially informing the complex multitrophic relationships underlying coevolutionary dynamics.

Forage maize is a central pillar of dairy cow feeding in France, directly influencing milk production. Drought significantly affects both maize yield and digestibility, which are both key parameters required for hybrid registration purposes. Research on maize inbred lines has revealed droughts’ notable effect on dry matter and cell wall digestibilities due to changes in cell wall composition, directly impacting forage quality. No such studies have been performed on forage maize hybrids however, which are the main seed type used in the agricultural sector. In this paper, we aimed to understand the impact of water and heat stress on forage maize digestibility, and to uncover the factors controlling it. We grew a panel of eleven modern forage maize hybrids for two years under four different controlled water stress modalities. These plants were agronomically, biochemically and histologically assayed, allowing us to perform a multiscale analysis to determine the traits responsible for variations in digestibility. By establishing a comprehensive heat and water stress index, we classified the environmental conditions. We demonstrated that under severe stress, ear production decreases significantly, but dry matter digestibility can be maintained through increased cell wall digestibility. This boost in cell wall digestibility was due to a reduction in p-hydroxycinnamic acid content and changes in lignin distribution, while lignin content and structure remained stable. The significant impact of lignin distribution on cell wall digestibility increased with the severity of the stress, reaching an extreme threshold where biochemical parameters solely account for digestibility variations. To improve maize digestibility, it will be necessary to better understand how the reduction in carbon flux under stress affects p-hydroxycinnamic acid levels without greatly impacting lignin content. Finally, our work suggests that the inclusion of moderate stress conditions in future maize breeding programs will be necessary to better adapt forage maize hybrids to climate change.

Abstract The wood properties (basic density and compressive strength parallel to the grain under green conditions), chemical components (lignin content, total polyphenol [as equivalent with tannic acid], monosaccharides [as equivalent with glucose], and ethanol-toluene extracts), and decay resistance were investigated in the heartwood of 50 naturally growing Pinus sylvestris L. trees from five different sites (Sites 1 to 5) in Ulaanbaatar, Mongolia. A mixed-effects model was developed to evaluate the among-site differences in measured properties. In addition, principal component analysis was applied to characterize the wood properties of sample trees in each site. The mean values of lignin content, polyphenol content, monosaccharide content, and mass loss caused by Trametes versicolor and Fomitopsis palustris were 30.3%, 95.3 mg/g, 38.9%, 34.4%, and 4.2%, respectively. Mass loss caused by T. versicolor was negatively correlated with lignin content but not with monosaccharide content. In contrast, mass loss caused by F. palustris showed a significant negative correlation with monosaccharide content but not with lignin content. Among-site differences were observed in polyphenol content, mass loss by T. versicolor , and physical and mechanical properties of wood. The principal component analysis results showed that trees from Site 4 showed higher mechanical properties and excellent decay resistance compared to other Sites. Based on these results, it is concluded that site selection is important to control the quality of the final products. In addition, improvement of wood quality can be achieved by selecting mother trees in the appropriate tree breeding program for establishing plantations.

Epichloë fungal endophytes can have a crucial role in plant growth and development. These fungi are recognized as beneficial microorganisms that form symbiotic relationships with grasses and provide several advantages to the host, such as improving stress resistance and promoting growth. The advantageous traits identified in natural ecosystems can, and have been, exploited in managed ecosystems such as pastoral farming in countries including New Zealand, Australia and the Americas. In the current study, Epichloë bromicola strain WBE1, an endophyte isolated from Hordeum brevisubulatum (wild-barley) was artificially inoculated into endophyte-free plants of H. brevisubulatum and H. vulgare (cultivated-barley, novel host) by researchers at Lanzhou University, China, to study grass-endophyte compatibility. WBE1 successfully infected 54% of the endophyte-free plants (n=107) of wild barley and 10% of the cultivated-barley plants (n=545). WBE1 colonisation enhanced the callus and lignin content in both grass hosts but also led to an increase in plant cell death. Cultivated-barley showed more resistance to endophytic infection as its infection frequency was lower than wild-barley. After 14 days, mycelial growth in both barley hosts was observed with the naked eye at the inoculation sites. The microscopy of endophyte infected leaf sheath tissue of wild barley showed that hyphae were branched and curved. In contrast, hyphae within leaf sheath tissues of cultivated-barley were slightly curved and unbranched. Inoculation of both grass hosts by WBE1 induced the expression of early signalling molecules including MAPK, which increased by 12 and 54% in cultivated barley compared with wild barley, 2- and 4-days post inoculation, respectively. Furthermore, O2 increased in both wild and cultivated barley after inoculation by 11 and 19%, respectively; H2O2 increased in both wild and cultivated barley by 67 and 72%, respectively and NO content increased in both wild and cultivated barley by 21 and 18%, respectively. After inoculation, regulated genes related to the synthesis of secondary metabolites involved in phytopathogen detection were expressed earlier in cultivated barley compared with wild barley. NADP+1 oxidoreductase and alcohol dehydrogenase (NADP+) activities were down-regulated in cultivated barley showing that the host was metabolically adjusted to environmental or physiological stress. The expression of signalling molecules and down-regulation of genes related to oxylipin biosynthesis, lipid oxidation, cellular response to environmental stimuli, oxidoreductase activity, and heme binding indicated that inoculation of cultivated barley by WBE1 triggered the host defence responses. This study investigated the gene transcription of an Epichloë endophyte strain across two different host plants, namely the original host and a novel host. The results showed that Epichloë can induce a defence response after inoculation, similar to that exhibited when being invaded by a phytopathogen and was expressed earlier in the novel host compared to the original host. The research results provide new ideas for further revealing the genetic foundations of the symbiotic relationship between Epichloë and their grass hosts.

Fast pyrolysis has emerged as an efficient thermo-chemical route for converting biomass into liquid fuels under moderate temperatures and short vapor residence times. This study presents a systematic Aspen Plus simulation framework for the fast pyrolysis of Wolffia globosa, a protein-rich aquatic plant with low lignin and high volatile matter content. The model employed a multi-stage RYield reactor configuration to represent progressive decomposition processes, integrated with separation and quenching units to preserve vapor quality and bio-oil composition. To establish model credibility, the framework was benchmarked against a published sawdust simulation and compared with reported pyrolysis trends of aquatic biomass. Simulations were performed across 400–600 °C with a fixed vapor residence time of 1.25 s. The results demonstrated that bio-oil yield increased with temperature, peaking at 58.62 wt% at 550 °C before slightly declining at higher temperatures due to secondary cracking. At this optimum condition, the simulated bio-oil contained approximately 89.25% organic compounds and 10.75% water by mass, indicating favorable properties for downstream upgrading. Gas yields increased monotonically with temperature, while char yields decreased, reflecting enhanced volatilization at higher thermal severity. The validated model showed less than 10% deviation from literature data and provides a replicable approach for simulating protein-rich aquatic biomass. Overall, this study highlights Wolffia globosa as a viable feedstock for sustainable bio-oil production and offers a transparent simulation methodology that can support future optimization and integration with circular wastewater treatment systems.

A significant amount of agricultural inputs, such as nitrogen fertilizers, is required due to the increased demand for food and fiber. Nitrogen applied to the soil through organic residues and compounds is more sustainable and environmentally friendly than through inorganic sources. This study evaluated the impact of organic nitrogen sources on carbon dynamics and microbial activity in a citrus orchard soil in northeastern Brazil. Five treatments (Control soil without fertilization, sheep manure + biofertilizer spray, sheep manure, castor bean cake, and green manure, thin branches from gliricidia cut from the plant) were tested. Fertilizers were applied under the plant canopy in 2021, 2022, and 2023 twice a year. Soil samples analysis showed that the distribution of soil organic carbon between particulate organic matter (POM) and mineral-associated organic matter (MAOM) was significantly influenced by the application of nitrogen-rich organic amendments. In the control treatment, the dominance of MAOM over POM followed a typical pattern observed in soils, reflecting the stable nature of MAOM and greater capacity for long-term carbon storage. However, the castor bean cake disrupted this balance by significantly increasing POM and, in some cases, reducing MAOM. In contrast, the green manure treatment did not change the POM and MAOM balance. The results suggest that green manure, with its higher lignin and polyphenol content, did not significantly enhance the labile carbon pool or disrupt carbon stabilization in the MAOM fraction. These findings underscore the role of residue composition in determining the fate of carbon in soil organic matter pools.

In-situ visual delignification and cell-scale kinetics modeling using confocal Raman microscopy.

Functional study on the regulation of lignin formation and disease resistance by the CpARF22 gene in Cucurbita pepo L.

Spatial heterogeneity in biomass yield and quality driving regional strategies for enhanced rice straw bioeconomic potential: a case study in Hunan, China.

Phenotypic, physiological and transcriptomic dynamics of Caragana liouana in a chronosequence of revegetated areas in Ningxia, Northwest China.

The lignocellulosic fibres obtained from dark jute are of superior strength but their coarseness often limits its industrial value, while fibre quality estimation processes further complicates plant selection.The lignocellulosic fibres obtained from dark jute are of superior strength but their coarseness often limits its industrial value. The tedious fibre quality estimation process further complicates the plant selection. Therefore, the current investigation was undertaken to identify some high-yielding and fine-fibre producing dark jute cultivars among a diverse panel based on the morphological and anatomical characteristics. Further, the role of lignin and some genes associated with its biosynthesis pathway, which influences fibre quality attributes was reconnoitered. The pooled analysis of variance for two years demonstrated significant variations among the genotypes across the evaluated traits. The genetic parameters, principal component analysis and correlation studies signified that the assessment of mid-diameter alongside plant height and basal diameter could enhance the selection efficiency for high fibre yielding cultivars. Among the bark anatomical traits, the area of the fiber wedge, lumen area, and number of fiber cells per bundle demonstrated the best estimates of fiber yield and quality. The lignin content (%) and the activities of the phenylalanine ammonia-lyase (PAL) and cinnamyl alcohol dehydrogenase (CAD) enzymes revealed significant differences among the genotypes under evaluation, with a positive association between them for fibre strength and fineness. The upregulated activity of the genes PAL, CAD, and 4-coumarate-CoA ligase (4CL) in the genotype BCCO 105 than its fine fibre-producing counterpart (OIN 95) depicted a critical role of these enzymes leading to disparity in fibre qualities. The high-fibre yielders (BCCO 105, OIN 123) and fine-fibre producing genotypes (OIN 95, OIN 128, BCCO 115, BCCO 120) detected in the present study will not only enrich the breeding materials for future fibre quality enhancements but also fulfill the quest of superior fibre producing dark jute cultivar which can be utilized in the industrial sector efficiently.

MicroRNAs (miRNAs) are known to play critical roles in plant immunity. However, their roles and molecular mechanisms in coordinating plant immunity and growth remain poorly characterized. Here, we report a rice-specific miRNA, osa-miR2871a-3p (miR2871), negatively regulates rice resistance to Xanthomonas oryzae pv oryzae (Xoo) by modulating cell wall biosynthesis. We demonstrated that the transcription factor OsWRKY72 directly binds to the OsMIR2871 promoter and activates its expression. miR2871 suppresses cell wall biosynthesis by directly targeting OsGT43G, which encodes an endoplasmic reticulum-localized glycosyltransferase protein. Genetic and physiological analysis revealed that both miR2871-downregulating (STTM2871) and OsGT43G-overexpressing (GT43G-ox) plants exhibit enhanced resistance to Xoo by maintaining a high level of cellulose and lignin content. Furthermore, we suggested that OsGT43G stabilizes OsMYB63 through physical interactions, co-activating OsCesA4/7/9 expression to confer rice resistance to Xoo. Finally, phenotypic assays showed that STTM2871, GT43G-ox, and OsWRKY72 knockout (wrky72-ko) lines confer broad-spectrum resistance to Xoo without yield penalty. Collectively, our findings uncover a rice-specific miRNA and provide novel insights into the role of the OsWRKY72-miR2871-OsGT43G module in mediating rice's response to Xoo, which offers a new strategy to improve rice resistance to bacterial pathogens.

Influence of cellulose content, lignin content, and fiber breakage on the tensile strength of fiber bundles extracted for different bamboo stem regions

Variations in lignin content deposited in the Congo fan and its potential for oxidative degradation

Uncovering the association of lignin biosynthesis and accumulation with Huangguan plum fruit hollowness and browning by integrated physiological and proteomic analysis.

C/N-Driven Synergies: Earthworms optimize CO2/N2O mitigation and soil quality in floral waste recycling.

Transform waste into profit: Extract licorice residue fiber to load Zr-MOF as a promising adsorbent.

Synergistic improvement of bleachability for poplar chemi-thermomechanical pulp in weakly-alkaline hydrogen peroxide bleaching by xylanase-pectinase pre-treatment.

Enhancing bioenergy from water hyacinth: pretreatment and anaerobic co-digestion.