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Conifers dominate the world's forest ecosystems and are the most widely planted tree species. Their giant and complex genomes present great challenges for assembling a complete reference genome for evolutionary and genomic studies. We present a 25.4-Gb chromosome-level assembly of Chinese pine (Pinus tabuliformis) and revealed that its genome size is mostly attributable to huge intergenic regions and long introns with high transposable element (TE) content. Large genes with long introns exhibited higher expressions levels. Despite a lack of recent whole-genome duplication, 91.2% of genes were duplicated through dispersed duplication, and expanded gene families are mainly related to stress responses, which may underpin conifers' adaptation, particularly in cold and/or arid conditions. The reproductive regulation network is distinct compared with angiosperms. Slow removal of TEs with high-level methylation may have contributed to genomic expansion. This study provides insights into conifer evolution and resources for advancing research on conifer adaptation and development.
Assuntos
Epigenoma , Evolução Molecular , Regulação da Expressão Gênica de Plantas , Genes de Plantas , Pinus/genética , Aclimatação/genética , Cromossomos de Plantas/genética , Cycadopsida/genética , Elementos de DNA Transponíveis/genética , Florestas , Redes Reguladoras de Genes , Tamanho do Genoma , Genômica/métodos , Íntrons , Magnoliopsida/genéticaRESUMO
Whole-genome duplication often results in a reduction in the lignin content in autopolyploid plants compared with their diploid counterparts. However, the regulatory mechanism underlying variation in the lignin content in autopolyploid plants remains unclear. Here, we characterize the molecular regulatory mechanism underlying variation in the lignin content after the doubling of homologous chromosomes in Populus hopeiensis. The results showed that the lignin content of autotetraploid stems was significantly lower than that of its isogenic diploid progenitor throughout development. Thirty-six differentially expressed genes involved in lignin biosynthesis were identified and characterized by RNA sequencing analysis. The expression of lignin monomer synthase genes, such as PAL, COMT, HCT, and POD, was significantly down-regulated in tetraploids compared with diploids. Moreover, 32 transcription factors, including MYB61, NAC043, and SCL14, were found to be involved in the regulatory network of lignin biosynthesis through weighted gene co-expression network analysis. We inferred that SCL14, a key repressor encoding the DELLA protein GAI in the gibberellin (GA) signaling pathway, might inhibit the NAC043-MYB61 signaling functions cascade in lignin biosynthesis, which results in a reduction in the lignin content. Our findings reveal a conserved mechanism in which GA regulates lignin synthesis after whole-genome duplication; these results have implications for manipulating lignin production.
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Lignina , Populus , Lignina/metabolismo , Populus/genética , Populus/metabolismo , Perfilação da Expressão Gênica , Fatores de Transcrição/genética , Fatores de Transcrição/metabolismo , Transdução de Sinais/genética , Regulação da Expressão Gênica de PlantasRESUMO
Lithium-sulfur (Li-S) batteries are highly regarded as the next-generation energy-storage devices because of their ultrahigh theoretical energy density of 2600â Wh kg-1 . Sulfurized polyacrylonitrile (SPAN) is considered a promising sulfur cathode to substitute carbon/sulfur (C/S) composites to afford higher Coulombic efficiency, improved cycling stability, and potential high-energy-density Li-SPAN batteries. However, the instability of the Li-metal anode threatens the performances of Li-SPAN batteries bringing limited lifespan and safety hazards. Li-metal can react with most kinds of electrolyte to generate a protective solid electrolyte interphase (SEI), electrolyte regulation is a widely accepted strategy to protect Li-metal anodes in rechargeable batteries. Herein, the basic principles and current challenges of Li-SPAN batteries are addressed. Recent advances on electrolyte regulation towards stable Li-metal anodes in Li-SPAN batteries are summarized to suggest design strategies of solvents, lithium salts, additives, and gel electrolyte. Finally, prospects for future electrolyte design and Li anode protection in Li-SPAN batteries are discussed.
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MAIN CONCLUSION: Six types of lignin-carbohydrate complex (LCC) fractions were isolated from Eucalyptus. The acidic dioxane treatment applied significantly improved the yield of LCCs. The extraction conditions had a limited impact on the LCC structures and linkages. Characterization of the lignin-carbohydrate complex (LCC) structures and linkages promises to offer insight on plant cell wall chemistry. In this case, Eucalyptus LCCs were extracted by aqueous dioxane, and then precipitated sequentially by 70% ethanol, 100% ethanol, and acidic water (pH = 2). The composition and structure of the six LCC fractions obtained by selective precipitation were investigated by sugar analysis, molecular weight determination, and 2D HSQC NMR. It was found that the acidic (0.05-M HCl) dioxane treatment significantly improved the yield of LCCs (66.4% based on Klason lignin), which was higher than the neutral aqueous dioxane extraction, and the extraction condition showed limited impact on the LCC structures and linkages. In the fractionation process, the low-molecular-weight LCCs containing a high content of carbohydrates (60.3-63.2%) were first precipitated by 70% ethanol from the extractable solution. The phenyl glycoside (PhGlc) bonds (13.0-17.0 per 100Ar) and highly acetylated xylans were observed in the fractions recovered by the precipitation with 100% ethanol. On the other hand, such xylan-rich LCCs exhibited the highest frequency of ß-O-4 linkages. The benzyl ether (BE) bonds were only detected in the fractions obtained by acidic water precipitation.
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Carboidratos/isolamento & purificação , Eucalyptus/metabolismo , Lignina/isolamento & purificação , Metabolismo dos Carboidratos , Carboidratos/química , Precipitação Química , Dioxanos/uso terapêutico , Lignina/química , Lignina/metabolismo , Espectroscopia de Ressonância Magnética , Peso MolecularRESUMO
Understanding and recognizing the structural characteristics of lignin-carbohydrate complexes (LCCs) and lignin in different growth stages and tissue types of bamboo will facilitate industrial processes and practical applications of bamboo biomass. Herein, the LCC and lignin samples were sequentially isolated from fibers and parenchyma cells of bamboo with different growth ages. The diverse yields of sequential fractions not only reflect the different biomass recalcitrance between bamboo fibers and parenchyma cells but also uncover the structural heterogeneity of these tissues at different growth stages. The molecular structures and structural inhomogeneities of the isolated lignin and LCC samples were comprehensively investigated. The results showed that the structural features of lignin and LCC linkages in parenchyma cells were abundant in ß-O-4 linkages but less with carbon-carbon linkages, suggesting that lignin and cross-linked LCC in parenchyma cells are simple in nature and easily to be tamed and tractable in the current biorefinery. Parallelly, the different ball-milled samples were directly characterized by high-resolution (800 M) solution-state 2D-HSQC NMR to analyze the whole lignocellulosic material. Overall, the scheme presented in this study will provide a comprehensive understanding of lignin and LCC linkages in fibers and parenchyma cells of bamboo and enable the utilization of bamboo biomass.
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Concerns about food safety and environmental impact from chemical surfactants have prompted interest in natural lignocellulosic materials as alternatives. In this study, we combined hydrated deep eutectic solvent (DES) pretreatment with ultrasound treatment to prepare lignocellulosic nanofibrils (LCNF) from bamboo shoot shells with appropriate surface properties for stabilizing Pickering emulsions. The pretreatment intensity effectively modulated the surface characteristics of LCNF, achieving desirable wettability through lignin retention and in-situ esterification. The resulting LCNF/curcumin Pickering emulsion (CPE) demonstrated curcumin protection and pH-responsive color changes, while the ensuing CPE/PVA composite film exhibited ultraviolet shielding, mechanical strength, oxygen barrier, and antioxidant properties. Furthermore, the CPE/PVA film showed promise as a real-time indicator for monitoring shrimp freshness, maintaining sensitivity to spoilage even after six months of storage. These findings advance the advancement of green LCNF technologies, providing eco-friendly solutions for valorizing bamboo shoot shells and enhancing the application of LCNF in Pickering emulsions.
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Curcumina , Emulsões , Lignina , Nanofibras , Curcumina/química , Lignina/química , Emulsões/química , Animais , Nanofibras/química , Antioxidantes/química , Solventes Eutéticos Profundos/química , Brotos de Planta/química , Sasa/química , Molhabilidade , Concentração de Íons de HidrogênioRESUMO
In recent years, nanocellulose (NC) has gained significant attention due to its remarkable properties, such as adjustable surface chemistry, extraordinary biological properties, low toxicity and low density. This review summarizes the preparation of NC derived from lignocellulosic biomass (LCB), including cellulose nanofibrils (CNF), cellulose nanocrystals (CNC), and lignin-containing cellulose nanofibrils (LCNF). It focuses on examining the impact of non-cellulosic components such as lignin and hemicellulose on the functionality of NC. Additionally, various surface modification strategies of NC were discussed, including esterification, etherification and silylation. The review also emphasizes the progress of NC application in areas such as Pickering emulsions, food packaging materials, food additives, and hydrogels. Finally, the prospects for producing NC from LCB and its application in food-related fields are examined. This work aims to demonstrate the effective benefits of preparing NC from lignocellulosic biomass and its potential application in the food industry.
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Biomassa , Celulose , Lignina , Lignina/química , Celulose/química , Nanopartículas/química , Embalagem de Alimentos/métodos , Aditivos Alimentares/química , Nanofibras/químicaRESUMO
Blending poly (butylene adipate-co-terephthalate) (PBAT) and polylactic acid (PLA) is a cost-effective strategy to obtain biodegradable plastic with complementary properties. However, the incompatibility between PBAT and PLA is a great challenge for fabricating high-performance composite films. Herein, the ethyl acetate fractionated lignin with the small glass transition temperature and low molecular weight was achieved and incorporated into the PBAT/PLA composite as a compatibilizer. The fractionated lignin can be uniformly dispersed within the PBAT/PLA matrix through a melt blending process and interact with the molecular chain of PBAT and PLA as a bonding bridge, which enhances the intermolecular interactions and reduces the interfacial tension of PBAT/PLA. By adding fractionated lignin, the tensile strength of the PBAT/PLA composite increased by 35.4 % and the yield strength increased by 37.7 %. Owing to lignin, the composite films possessed the ultraviolet shielding function and exhibited better water vapor barrier properties (1.73 ± 0.08 × 10-13 g·cm/cm2·s·Pa). This work conclusively demonstrated that fractionated lignin can be used as a green compatibilizer and a low-cost functional filler for PBAT/PLA materials, and provides guidance for the application of lignin in biodegradable plastics.
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Alcenos , Plásticos Biodegradáveis , Lignina , Ácidos Ftálicos , Adipatos , Poli A , PoliésteresRESUMO
The practical applications of lithium-sulfur (Li-S) batteries have severely been hindered by notorious shuttle effect and sluggish redox kinetics of lithium polysulfide intermediates (LiPSs), which bring about rapid capacity degradation, low coulombic efficiency and poor cycling stability. In this work, 1T-rich MoS2 nanosheets are in-situ developed onto the conductive porous carbon matrix (1T-rich MoS2@PC) as efficient polysulfide promotors for high-performance Li-S batteries. The porous carbon skeleton tightly anchors MoS2 nanosheets to prevent their reaggregation and ensures accessible electrical channels, and at the same time provides a favorable confined space that promotes the generation of 1T-rich MoS2 structure. More importantly, the uniformly distributed metallic 1T-rich MoS2 nanosheets not only affords rich sulfphilic sites and high binding energy for immobilizing LiPSs, but also favors rapid electron transfer and LiPSs conversation kinetics, substantially regulating sulfur chemistry in working cells. Consequently, the Li-S cell assembled with 1T-rich MoS2@PC modified separator delivers a remarkable cycling stability with ultralow capacity decay rate of 0.067% over 500 cycles at 1C. Encouragingly, under harsh conditions (high sulfur loading of 4.78 mg cm-2 and low E/S ratio of 8 µL mg-1), a favorable electrochemical performance can still be demonstrated. This study highlights the profitable design of 1T-rich MoS2/carbon based electrocatalyst for suppressing shuttle effect and promoting catalytic conversation of LiPSs, and has the potential to be applied to in other energy storage systems.
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Utilizing renewable lignocellulosic resources for wastewater remediation is crucial to achieving sustainable social development. However, the resulting by-products and the synthetic process characterized by complexity, high cost, and environmental pollution limit the further development of lignocellulose-based materials. Here, we developed a sustainable strategy that involved a new functional deep eutectic solvent (DES) to deconstruct industrial xylose residue into cellulose-rich residue with carboxyl groups, lignin with carboxyl and quaternary ammonium salt groups, and DES effluent rich in lignin fragments. Subsequently, these fractions equipped with customized functionality were used to produce efficient wastewater remediation materials in cost-effective and environmentally sound manners, namely, photocatalyst prepared by carboxyl-modified cellulose residue, biochar-based adsorbent originated from modified lignin, and flocculant synthesized by self-catalytic in situ copolymerization of residual DES effluent at room temperature. Under the no-waste principle, this strategy upgraded the whole components of waste lignocellulose into high-value-added wastewater remediation materials with excellent universality. These materials in coordination with each other can stepwise purify high-hazardous mineral processing wastewater into drinkable water, including the removal of 99.81% of suspended solids, almost all various heavy metal ions, and 97.09% chemical oxygen demand, respectively. This work provided promising solutions and blueprints for lignocellulosic resources to alleviate water shortages while also advancing the global goal of carbon neutrality.
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Although the effects of cellulose crystallinity and lignin content as two major structural features on enzymatic hydrolysis have been extensively studied, debates regarding their effects still exist. In this study, reconstitution of cellulose and lignin after 1-ethyl-3-methylimidazolium acetate ([C(2)mim][OAc]) pretreatment was proposed as a new method to study their effects on enzymatic digestibility. Different mechanisms of lignin content for reduction of cellulose hydrolysis were found between the proposed method and the traditional method (mixing of cellulose and lignin). The results indicated that a slight change of the crystallinity of the reconstituted materials may play a minor role in the change of enzyme efficiency. In addition, the present study suggested that the lignin content does not significantly affect the digestibility of cellulose, whereas the conversion of cellulose fibers from the cellulose I to the cellulose II crystal phase plays an important role when an ionic liquid pretreatment of biomass was conducted.
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Celulases/antagonistas & inibidores , Celulases/metabolismo , Celulose/metabolismo , Inibidores Enzimáticos/metabolismo , Imidazóis/química , Líquidos Iônicos/química , Lignina/metabolismo , HidróliseRESUMO
Deep eutectic solvents (DESs) have emerged as promising and eco-friendly solvents for the efficient extraction of lignin from biomass due to their low cost and environmental benefits. Nevertheless, the prevalent use of acidic DESs in lignin extraction often results in excessive depolymerization and recondensation of lignin, thereby impeding its downstream applications. In this study, we developed a range of alkaline DESs (ADESs), both pure and peroxide-containing, for the extraction of high-quality lignin from bamboo. Moreover, carbon dioxide (CO2) was employed for the precipitation and regeneration of the extracted lignin. The obtained lignin fractions were comprehensively characterized in terms of yield, purity, morphology, solubility, structural features, and anti-UV/oxidant activity. The results showed that the monoethanolamine-based ADES demonstrated superior performance among the pure ADESs. Structural analysis confirmed the well-preserved substructures of lignin fractions obtained using ADESs, with ß-O-4 bond retention ranging from 49.8 % to 68.4 %. The incorporation of a suitable amount of peroxide improved lignin yield, morphology, solubility, and anti-UV/oxidant activity. Additionally, the anti-UV/oxidant activity of lignin exhibited a positive correlation with its phenolic hydroxyl content. This study provides a valuable reference for the green and sustainable production and valorization of lignin within the existing biorefinery framework.
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Solventes Eutéticos Profundos , Lignina , Lignina/química , Solventes/química , Antioxidantes , Biomassa , Oxidantes , HidróliseRESUMO
To comprehend the biosynthesis processes of conifers, it is essential to investigate the disparity between the cell wall shape and the interior chemical structures of polymers throughout the development of Chinese pine. In this study, branches of mature Chinese pine were separated according to their growth time (2, 4, 6, 8 and 10 years). The variation of cell wall morphology and lignin distribution was comprehensively monitored by scanning electron microscopy (SEM) and confocal Raman microscopy (CRM), respectively. Moreover, the chemical structures of lignin and alkali-extracted hemicelluloses were extensively characterized by nuclear magnetic resonance (NMR) and gel permeation chromatography (GPC). The thickness of latewood cell walls increased steadily from 1.29 µm to 3.38 µm, and the structure of the cell wall components became more complicated as the growth time increased. Based on the structural analysis, it was found that the content of ß-O-4 (39.88-45.44/100 Ar), ß-ß (3.20-10.02/100 Ar) and ß-5 (8.09-15.35/100 Ar) linkages as well as the degree of polymerization of lignin increased with the growth time. The complication propensity increased significantly over 6 years before slowing to a trickle over 8 and 10 years. Furthermore, alkali-extracted hemicelluloses of Chinese pine mainly consist of galactoglucomannans and arabinoglucuronxylan, in which the relative content of galactoglucomannans increased with the growth of the pine, especially from 6 to 10 years.
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Parede Celular , Lignina , Pinus , Polissacarídeos , Lignina/química , Pinus/química , Pinus/crescimento & desenvolvimento , Polissacarídeos/química , Parede Celular/química , Parede Celular/metabolismoRESUMO
Phytoremediation with energy crops is considered an integrated technology that provides both environment and energy benefits. Herein, the sweet sorghum cultivated on Cd-contaminated farmland (1.21 mg/kg of Cd in the soil) showed promising phytoremediation potential, and the approach for utilizing sorghum stalks was explored. Sweet sorghum bagasse with Cd contamination was pretreated with dilute acid in order to improve enzymatic saccharification and achieve Cd recovery, resulting in harmless and value-added utilization. After pretreatment, hemicelluloses were dramatically degraded, and the lignocellulosic structures were partially deconstructed with xylan removal up to 98.1%. Under the optimal condition (0.75% H2SO4), the highest total sugar yield was 0.48 g/g of raw bagasse; and nearly 98% of Cd was enriched in the liquid phase. Compared with normal biomass, Cd reduced the biomass recalcitrance and further facilitated the deconstruction of biomass under super dilute acid conditions. This work provided an example for the subsequent valorization of Cd-containing biomass and Cd recovery, which will greatly facilitate the development of phytoremediation of heavy metal contaminated soil.
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Cádmio , Sorghum , Cádmio/metabolismo , Sorghum/química , Biodegradação Ambiental , Hidrólise , Solo , BiomassaRESUMO
In this study, light-colored lignin was extracted from bamboo shoot shells (BSS) using a hydrated deep eutectic solvent (DES) pretreatment. The hydrated DES used in pretreatment consist of formic acid, benzyl triethylammonium chloride (BTEAC) and water. The pretreatment using a hydrated DES containing 30% water (H30) demonstrate efficient delignification (82.9%). Additionally, the hydrated DES protected the ß-O-4 linkage from excessive cleavage and recondensation as well as keep the light-colored of lignin. Moreover, the hydrated DES extracted lignin exhibits superior antioxidant performance and tyrosinase inhibitory capacity compared to the control. Notably, incorporating 5% lignin of H30-extracted lignin into a commercial suncream led to a remarkable enhancement of the SPF value, elevating from 14.8 to 32.6. In summary, the proposed hydrated DES pretreatment method offers significant benefits for extracting light-colored lignin, thereby promoting the multifunctional application of lignin in cosmetics.
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Solventes Eutéticos Profundos , Lignina , Solventes , Biomassa , Água , HidróliseRESUMO
Effective separation of lignin macromolecules from the xylose pre-hydrolysates (XPH) during the xylose production, thus optimizing the separation and purification process of xylose, is of great significance for reducing the production costs, achieving the high value-added utilization of lignin and increasing the industrial revenue. In this study, a simple and robust method (pH adjustment) for the separation of lignin from XPH was proposed and systematically compared with the conventional acid-promoted lignin precipitation method. The results showed that the lignin removal ratio (up to 60.34 %) of this simple method was higher than that of the conventional method, and the proposed method eliminated the necessity of heating and specialized equipment, which greatly reduced the separation cost. Meanwhile, this simple method does not destroy the components in XPH (especially xylose), ensuring the yield of the target product. On the other hand, the obtained lignin was nano-scale with less condensed structures, which also possessed small molecular weights with narrow distribution, excellent antioxidant activity (8-14 times higher than commercial antioxidants) and UV protection properties. In conclusion, the proposed simple separation method could effectively separate lignin from XPH at low cost, and the obtained lignin had potential commercial applications, which would further enhance the overall profitability of industrial production.
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Lignina , Xilose , Lignina/química , Xilose/química , Hidrólise , Bebidas AlcoólicasRESUMO
In this work, a rapid one-pot hydrated deep eutectic solvent (DES) pretreatment was proposed to facilitate the conversion of carbohydrates from lignocellulosic biomass to monosaccharides. Specifically, the pure and hydrated DES based on benzyl triethylammonium chloride (BTEAC), formic acid (FA) and water was used to pretreat bamboo shoot shells (BSS) by microwave heating. The pretreated solid residues were enzymatically saccharified to produce fermentable sugars, and the hydrolyzed carbohydrates and lignin remained in the hydrolyzate. The results showed that the yield of monosaccharides from the hydrated DES hydrolyzate (193.7-228.4 g/kg) was significantly higher than that (45.9-66.1 g/kg) of pure DES. The 30% hydrated DES pretreatment achieved the best glucose yield (89.03%) and a total monosaccharides yield of 555.4 g/kg, which corresponded to a conversion ratio of carbohydrates to monosaccharides of 87.0%. The proposed process is a robust method for the efficiently convert carbohydrates from BSS into monosaccharides.
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Carboidratos , Solventes Eutéticos Profundos , Lignina/química , Glucose/química , Monossacarídeos , Hidrólise , Biomassa , Solventes/químicaRESUMO
Utilizing starch, an abundant polysaccharide, as the renewable filler to blend with poly(butylene adipate-co-terephthalate) (PBAT) is a feasible tactic to construct cost-effective and high-performance biodegradable materials. It's worth noting that the thermal processing properties of starch can be manipulated by its plasticized behavior. Herein, epoxidized soybean oil (ESO) and glycerol were used as the plasticizer for native corn starch and the plasticized starch was integrated with PBAT to manufacture starch-based biodegradable blend films. ESO breaks the hydrogen bonds between starch chains through the fatty chains grafting reaction and increases the distance between starch molecular chains due to the large molecular weight of ESO. Meanwhile, glycerol molecules are incorporated into the starch molecular chains, and fatty chains grafted starch chains, effectively reducing the intermolecular forces of molecular chains. On account of the synergistic plasticization of ESO and glycerol which possess good compatibility with PBAT, the PSG20E10 blend film achieved a tensile strength, an elongation at break of 16.11 MPa and 612.09 %, and the balanced water and oxygen permeability properties.
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Glicerol , Poliésteres , Poliésteres/química , Amido/química , AdipatosRESUMO
In this work, a green and robust pretreatment which integrated acetic acid-catalyzed hydrothermal and wet mechanical pretreatment, was developed to efficiently produce high yield (up to 40.12%) of xylooligosaccharides and digestible substrates from Caffeoyl Shikimate Esterase down-regulated and control poplar wood. Subsequently, superhigh yield (more than 95%) of glucose and residual lignin were obtained after a moderate enzymatic hydrolysis. The residual lignin fraction exhibited a well-preserved ß-O-4 linkages (42.06/100Ar) and high S/G ratio (6.42). Subsequently, lignin-derived porous carbon was successfully synthesized, and it exhibited a high specific capacitance of 273.8 F g-1 at 1.0 A g-1 and long cycling stability (remained 98.5% after 10,000 cycles at 5.0 A g-1) compared to control poplar wood, demonstrating that special advantage of this genetically-modified poplar in this integrated process. This work developed an energy-saving and eco-friendly pretreatment technology as a waste-free route for converting different lignocellulosic biomass to multiple products.
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Esterases , Lignina , Hidrólise , MadeiraRESUMO
Epigenetics has been revealed to play a crucial role in the long-term memory in plants. However, little is known about whether the epigenetic modifications occur with age progressively in conifers. Here, we present the single-base resolution DNA methylation landscapes of the 25-gigabase Chinese pine (Pinus tabuliformis) genome at different ages. The result shows that DNA methylation is closely coupled with the regulation of gene transcription. The age-dependent methylation profile with a linearly increasing trend is the most significant pattern of DMRs between ages. Two segments at the five-prime end of the first ultra-long intron in DAL1, a conservative age biomarker in conifers, shows a gradual decline of CHG methylation as the age increased, which is highly correlated with its expression profile. Similar high correlation is also observed in nine other age marker genes. Our results suggest that DNA methylation serves as an important epigenetic signature of developmental age in conifers.