Search Results (47)

Oxybenzone (OBZ), an organic ultraviolet filter, is an emerging contaminant posing severe threats to ecosystem health. Using tobacco (Nicotiana tabacum) as a model plant, this study investigated the alleviation mechanisms of exogenous silicon (Na₂SiO₃, Si) and bamboo-based biochar (Bc) under OBZ stress. We systematically analyzed physiological and biochemical responses, including phenotypic parameters, reactive oxygen species metabolism, photosynthetic function, chlorophyll synthesis, and endogenous hormone levels. Results reveal that OBZ significantly inhibited tobacco growth and triggered a reactive oxygen species (ROS) burst. Additionally, OBZ disrupted antioxidant enzyme activities and hormonal balance. Exogenous Bc mitigated OBZ toxicity by adsorbing OBZ, directly scavenging ROS, and restoring the ascorbate-glutathione (AsA-GSH) cycle, thereby enhancing photosynthetic efficiency, while Si alleviated stress via cell wall silicification, preferential regulation of root development and hormonal signaling, and repair of chlorophyll biosynthesis precursor metabolism and PSII function. The mechanisms of the two stress mitigators were complementary, Bc primarily relied on physical adsorption and ROS scavenging, whereas Si emphasized metabolic regulation and structural reinforcement. These findings provide practical strategies for simultaneously mitigating organic UV filter pollution and enhancing plant resilience in contaminated soils. Full article

Lead (Pb) contamination in Moso bamboo forests poses a challenge in terms of sustainable development and raises concerns about the safety of bamboo shoots for consumption. However, the physiological impacts of Pb stress on Moso bamboo growth and the molecular mechanisms governing its adaptive responses remain poorly understood. This study comprehensively investigated the physiological and transcriptomic responses of Moso bamboo to Pb stress. The results showed that low concentrations (1–10 µM) of Pb stress had minimal adverse effects on biomass accumulation and the photochemical quantum yield of PSII in Moso bamboo. However, at a high Pb concentration (50 µM), the growth of roots was significantly inhibited, while Pb accumulation in the roots and shoots reached 15,611 mg·kg⁻¹ and 759 mg·kg⁻¹, respectively. The uptake of Pb was increased as the external Pb concentration increased, but the xylem loading of Pb reached saturation at 57.79 µM after six-hour exposure. Pb was mainly localized in the epidermis and pericycle cells in the roots, where the thickening of cell walls in these cells was found after Pb treatment. Transcriptomic profiling identified 1485 differentially expressed genes (DEGs), with significant alterations in genes associated with metal cation transporters and cell wall synthesis. These findings collectively indicate that Moso bamboo is a Pb-tolerant plant, characterized by a high accumulation capacity and efficient xylem loading. The tolerance mechanism likely involves the transcriptional regulation of genes related to heavy metal transport and cell wall biosynthesis. Full article

Foliar fertilization, an effective strategy for enhancing crop yields, is relatively uncommon in bamboo cultivation. To investigate the impact of potassium fertilizer applied directly to bamboo leaves, we applied K₂CO₃ on the fresh leaves of 1-year-old Neosinocalamus affinis culms. The results indicated that potassium fertilization significantly promoted leaf growth and development, evidenced by thicker leaf and epidermal and mesophyll cells and increased areas of bulliform and fusoid cells. Additionally, the chlorophyll content rose, while the moisture levels declined. Notably, the soluble sugar, starch, and non-structural carbohydrate (NSC) contents in the leaves also increased. Further analysis of the sugar metabolism revealed that the exogenous potassium application boosted the activities of key enzymes involved in sucrose metabolism, including soluble acid convertase (SAI), cell wall invertase (CWI), sucrose synthase (SuSy), and sucrose phosphate synthetase (SPS). The foliar application of K₂CO₃ also promoted starch synthesis in the leaves by elevating the activities of ADPG pyrophosphorylase (AGPase), soluble starch synthase (SSS), and granular-bound starch synthase (GBSS), while simultaneously diminishing the activities of starch phosphorylase (STP), α-amylase, and β-amylase. Moreover, the targeted application of K₂CO₃ significantly reduced the contents of malondialdehyde (MDA) and hydrogen peroxide (H₂O₂) and significantly enhanced the activities of superoxide dismutase (SOD), catalase (CAT), and peroxidase (POD), thereby improving the stress resistance of bamboo leaves. This study suggested that the foliar application of potassium fertilizer promoted leaf growth, enhanced bamboo’s sugar metabolism and storage, and increased the stress resistance of bamboo leaves. Full article

Bamboo is a fast-growing lignocellulosic plant in nature. It is an abundant and renewable resource with wide applications. The processing of bamboo results in a large amount of residue. In this paper, we developed a method to utilize bamboo residue to prepare a novel lightweight porous molding material. A hydrated thermochemical grinding process was proposed to disintegrate bamboo fibers and activate bamboo’s own binding components. The influence of the water removal by pressure from bamboo suspension and subsequent different drying methods on the product’s properties was evaluated. The two-step drying ensured a low production cost and high product quality. The bamboo molding material was characterized based on thermal stability, morphology, functional groups, particle size distribution, crystallinity, and mechanical strength. A lightweight porous material was obtained with a density of 0.23–0.35 g/cm³ by freeze-drying. A high mechanical strength was obtained with a tensile strength of 0.62 MPa and a compressive strength of 10.31 MPa by oven drying. The auto-adhesive mechanisms, including fiber anchorage, polymerization, water plasticization, and heat plasticization, were discussed. The bamboo molding material is a reconstruction of bamboo cell wall components and is easy to recycle. It has potential applications in construction and buildings, packaging, and indoor furnishings. Full article

Microtubule-associated proteins (MAPs) play a pivotal role in the assembly and stabilization of microtubules, which are essential for plant cell growth, development, and morphogenesis. A class of plant-specific MAPs, MAP65, plays largely unexplored roles in moso bamboo (Phyllostachys edulis). This study identified 19 PeMAP65 genes in moso bamboo, systematically examining their phylogenetic relationships, conserved motifs, gene structures, collinearity, and cis-acting elements. Analysis of gene expression indicated that PeMAP65s exhibit tissue-specific expression patterns. Functional differentiation was investigated among the members of different PeMAP65 subfamilies according to their expression patterns in different development stages of bamboo shoots. The expression of PeMAP65-18 was positively correlated with the expression of genes involved in secondary cell wall (SCW) biosynthesis. Y1H and Dual-LUC assays demonstrated that the transcription of PeMAP65-18 was upregulated by PeMYB46, a key transcription factor of SCW biosynthesis. The result of subcellular localization showed that PeMAP65-18 was located in cortical microtubules. We speculate that PeMAP65-18 may play a crucial role in the SCW deposition of moso bamboo. This comprehensive analysis of the MAP65 family offers novel insights into the roles of PeMAP65s in moso bamboo, particularly in relation to the formation of SCWs. Full article

Microbes naturally inhabit bamboo-based materials in outdoor environments, sequentially contributing to their deterioration. Fungi play a significant role in deterioration, especially in environments with abundant water and favorable temperatures. Alkali treatment is often employed in the pretreatment of round bamboo to change its natural elastic and aesthetic behaviors. However, little research has investigated the structure and dynamics of fungal communities on alkali-treated round bamboo during natural deterioration. In this work, high-throughput sequencing and multiple characterization methods were used to disclose the fungal community succession and characteristic alterations of alkali-treated round bamboo in both roofed and unroofed habitats throughout a 13-week deterioration period. In total, 192 fungal amplicon sequence variants (ASVs) from six phyla were identified. The fungal community richness of roofed bamboo samples declined, whereas that of unroofed bamboo samples increased during deterioration. The phyla Ascomycota and Basidiomycota exhibited dominance during the entire deterioration process in two distinct environments, and the relative abundance of them combined was more than 99%. A distinct shift in fungal communities from Basidiomycota dominant in the early stage to Ascomycota dominant in the late stage was observed, which may be attributed to the increase of moisture and temperature during succession and the effect of alkali treatment. Among all environmental factors, temperature contributed most to the variation in the fungal community. The surface of round bamboo underwent continuous destruction from fungi and environmental factors. The total amount of cell wall components in bamboo epidermis in both roofed and unroofed conditions presented a descending trend. The content of hemicellulose declined sharply by 8.3% and 11.1% under roofed and unroofed environments after 9 weeks of deterioration. In addition, the contact angle was reduced throughout the deterioration process in both roofed and unroofed samples, which might be attributed to wax layer removal and lignin degradation. This study provides theoretical support for the protection of round bamboo under natural weathering. Full article

In this study, moso bamboo was used as a raw material. To increase the plasticity of bamboo to achieve a greater softening effect, the softening method of hydrothermal treatment was used. Hardness and the flexural elastic modulus were used as the evaluation indices, and the crystallinity and main functional groups of the softened bamboo were analysed using X-ray diffraction and Fourier-transform infrared spectroscopy. Combined with the examination of timber colour, micromorphology, bending strength, and nanomechanical tests, our analysis showed the effects of the hydrothermal treatment on bamboo. The results showed that the hardness and flexural moduli of bamboo decreased with the increase in hydrothermal treatment temperature. However, cracking occurred after 3.5 and 4 h of treatment at 180 °C and 190 °C. This indicated that the softening effect was most pronounced when the treatment temperature and time were 180 ℃ and 3 h, respectively. The cellulose crystallinity of bamboo increased and then decreased with the increase in treatment temperature. Cracks were produced in the cell structure, starch locally disappeared, and the hardness and the elasticity modulus of the thin-walled bamboo cells first increased and then decreased with the increase in treatment temperature. Full article

The Moso bamboo culm neck, connected with the rhizome and the shoot bud, is an important hub for connecting and transporting the aboveground and belowground systems of bamboo for the shoot bud development and rapid growth. Our previous study revealed that the culm neck generally undergoes six different developmental stages (CNS1–CNS6), according to the primary thickening growth of the underground shoot bud. However, the molecular mechanism of the culm neck development remains unknown. The present study focused on the developmental process of the CNS3–CNS5 stages, representing the early, middle, and late elongation stages, respectively. These stages are densely packed with vascular tissues and consist of epidermis, hypodermis, cortex, and ground tissue. Unlike the hollow structure of the culms, the culm necks are solid structures. As the culm neck continues to grow, the lignin deposition increases noticeably, contributing to its progressive strengthening. For the transcriptome analysis, a total of 161,160 transcripts with an average length of 2373 were obtained from these stages using both PacBio and Illumina sequencing. A total of 92.2% of the reads mapped to the Moso bamboo reference genome. Further analysis identified a total of 5524 novel genes and revealed a dynamic transcriptome. Secondary-metabolism- and transport-related genes were upregulated particularly with the growth of the culm neck. Further analysis revealed the molecular processes of lignin accumulation in the culm neck, which include differentially expressed genes (DEGs) related to cell wall loosening and remodeling and secondary metabolism. Moreover, the upregulations of transcription factors such as MYBH and RSM in the MYB family play crucial roles during critical transitions in the culm neck development, such as changes in the angle between the rhizome and the culm neck. Our new findings provide essential insights into the cellular roadmaps, transcriptional networks, and key genes involved in the culm neck development. Full article

The ATP-binding cassette subfamily B (ABCB) is an important transporter family, and many members are well known for their auxin transport function. However, reports on the function of the ABCB genes during Moso bamboo development are few. In this study, we identified and characterized 37 PhABCB genes in Moso bamboo and classified them into five subgroups, Ⅰ–Ⅴ. We further observed gene family expansion and gene loss events during the evolution of the PhABCB gene family. It was found that the expansion of the PhABCB family was mainly attributed to the whole-genome duplication and DNA-transposed duplication models. Gene co-expression analysis and quantitative real-time PCR revealed that several PhABCB genes may be involved in the development of the secondary cell wall (SCW) during the rapid growth of Moso bamboo. Through examining their expression in different parts of the bamboo internode where the cell walls exhibited different developmental stages, the roles of eight candidate PhABCBs in the SCW development were further characterized. Of the eight PhABCB genes, PhABCB7, PhABCB11, PhABCB14, and PhABCB21 may be involved in the SCW biogenesis in Moso bamboo. This study provides the basis for discovering the potential role of PhABCB genes in Moso bamboo cell wall development; further studies are needed to elucidate how these PhABCBs function in SCW development by regulating the polar transport of auxin. Full article

Bamboo’s mechanical and aesthetic properties are significantly influenced by fungi. However, few studies have been conducted to investigate the structure and dynamics of fungal communities in bamboo during its natural deterioration. In this study, fungal community succession and characteristic variations of round bamboo in roofed and unroofed environments over a period of 13 weeks of deterioration were deciphered using high-throughput sequencing and multiple characterization methods. A total of 459 fungal Operational Taxonomic Units (OTUs) from eight phyla were identified. The fungal community’s richness of roofed bamboo samples showed an increasing trend, whereas that of unroofed bamboo samples presented a declining trend during deterioration. Ascomycota and Basidiomycota were the dominant phyla throughout the deterioration process in two different environments: Basidiomycota was found to be an early colonizer of unroofed bamboo samples. Principal Coordinates Analysis (PCoA) analysis suggested that the deterioration time had a greater impact on fungal community variation compared to the exposure conditions. Redundancy analysis (RDA) further revealed that temperature was a major environmental factor that contributed to the variation in fungal communities. Additionally, the bamboo epidermis presented a descending total amount of cell wall components in both roofed and unroofed conditions. The correlation analysis between the fungal community and relative abundance of three major cell wall components elucidated that Cladosporium was negatively correlated with hemicellulose in roofed samples, whereas they presented a positive correlation with hemicellulose and a negative correlation with lignin in unroofed samples. Furthermore, the contact angle decreased during the deterioration process in the roofed as well as unroofed samples, which could arise from the degradation of lignin. Our findings provide novel insights into the fungal community succession on round bamboo during its natural deterioration and give useful information for round bamboo protection. Full article

Phase-change energy-storage paraffin regulates the thermal management of buildings, and the material can regulate room temperature as it absorbs and discharges heat. As a porous adsorbent material, bamboo has high permeability. The aim of this study was to increase the amount of paraffin inside bamboo and the latent heat of the phase change. It was performed using vacuum pressurization (VP) and ultra-high-pressure (UHP) impregnation treatments. The effect of UHP impregnation and properties of bamboo were studied. The weight gain, paraffin loss and dimensional changes were measured and compared. The morphology of UHP-impregnated bamboo were characterized using X-ray diffraction (XRD), differential scanning calorimetry (DSC), Fourier transform infrared spectroscopy (FTIR) and scanning electron microscopy (SEM). The main conclusions are as follows: After UHP impregnation, the highest weight gain was 42%. The loss of paraffin was low, and a high weight percentage gain was maintained. The crystallinity of cellulose decreased to 24% at 100 MPa. The latent heat of the bamboo slices was up to 25.66 J/g at 50 MPa, and the phase change temperature was close to room temperature. At 150 MPa, the hydroxyl content was reduced, and the hydrophilicity decreased. In addition, the content of substances such as hemicellulose in the amorphous zone was reduced under UHP, no new characteristic peaks appeared, and no chemical modifications occurred. The vascular bundles were compressed and dense, and the pores and cell gaps decreased. The thin-walled cells were deformed, and the original cell structure was completely destroyed. The surface of the cells was wrapped or covered with paraffin, confirming that the paraffin could impregnate the bamboo cells under UHP. Therefore, bamboo impregnated with paraffin can regulate temperature and save energy in buildings. It is resistant to biological attacks, and UHP improves the impregnation efficiency. Full article

Bamboo is one of the essential ornamental plants that is widely used as a decorative landscape element in gardens. Phyllostachys violascens cv. Viridisulcata has a unique internode color phenotype with yellow culm and green sulcus, but their structural and development differences remain unknown. In the current study, we analyzed the histological analysis of internode cross-sections through SEM and microscopy. These results revealed that the vascular bundles distributed in the culm were organized in oblique rows and multiple lines. In contrast, the vascular bundles’ distribution in the sulcus was much more random. The distribution density, maximum length, and maximum width of vascular bundles were also differentiated between the sulcus and the culm. Further, the cell wall thickness of fiber cells in the culm was more than 30% thicker than the sulcus. The FT-IR analysis identified that the culm and sulcus had similar structural properties. The total lignin content measurement revealed that lignin accumulated more in the sulcus than in the culm. Additionally, we identified the lignin biosynthesis pathway genes, Pv4CL and PvC4H, which were differentially expressed between the culm and sulcus through transcriptomic data and qPCR analyses. In conclusion, our results identified that the vascular bundles’ structure differed between the culm and sulcus, and Pv4CL and PvC4H genes might play an essential role in their development. Full article

As the main component of plant cell walls, lignin can not only provide mechanical strength and physical defense for plants, but can also be an important indicator affecting the properties and quality of wood and bamboo. Dendrocalamus farinosus is an important economic bamboo species for both shoots and timber in southwest China, with the advantages of fast growth, high yield and slender fiber. Caffeoyl-coenzyme A-O-methyltransferase (CCoAOMT) is a key rate-limiting enzyme in the lignin biosynthesis pathway, but little is known about it in D. farinosus. Here, a total of 17 DfCCoAOMT genes were identified based on the D. farinosus whole genome. DfCCoAOMT1/14/15/16 were homologs of AtCCoAOMT1. DfCCoAOMT6/9/14/15/16 were highly expressed in stems of D. farinosus; this is consistent with the trend of lignin accumulation during bamboo shoot elongation, especially DfCCoAOMT14. The analysis of promoter cis-acting elements suggested that DfCCoAOMTs might be important for photosynthesis, ABA/MeJA responses, drought stress and lignin synthesis. We then confirmed that the expression levels of DfCCoAOMT2/5/6/8/9/14/15 were regulated by ABA/MeJA signaling. In addition, overexpression of DfCCoAOMT14 in transgenic plants significantly increased the lignin content, xylem thickness and drought resistance of plants. Our findings revealed that DfCCoAOMT14 can be a candidate gene that is involved in the drought response and lignin synthesis pathway in plants, which could contribute to the genetic improvement of many important traits in D. farinosus and other species. Full article

Furfurylation is an effective and green method for wood or bamboo modification that can significantly improve its physical and mechanical properties and the resistance against biological deterioration and the attack of subterranean termites. To elucidate the effect of furfurylation on the physical and multiscale mechanical properties of bamboo, the conditions of the furfurylation process were modified to cause an independent variation of the physical and multiscale mechanical properties in differently-treated bamboo samples. This was achieved by impregnating bamboo samples with solutions containing 15%, 30%, 50%, or 70% furfuryl alcohol (FA) by either of the two impregnation processes, vacuum pressure (V-P) and soaking (S) impregnation, while applying different curing conditions (wet- or dry-curing). The physical properties we measured included the absorption rate, weight percent gain (WPG), swelling efficiency (SE), and anti-swelling efficiency (ASE); the macro-mechanical properties involved the modulus of rupture (MOR), the modulus of elasticity (MOE), parallel-to-grain compressive strength (CS), and tensile strength (TS); the micro-mechanical properties included the tensile strength of bamboo’s vascular bundle and hardness and the indentation modulus of bamboo’s fiber cell walls. Finally, the correlation between the different physical and mechanical properties of the modified bamboo samples was analyzed. The results indicate that V-P impregnation made bamboo more permissible for the penetration of FA, while wet-curing was more conducive to ensuring a high curing rate. The dimensional stability of the bamboo samples treated with a high FA concentration through V-P impregnation and of those furfurylated by the S-Wet process using either medium or high FA concentrations was significantly increased. However, the dimensional stability of the bamboo samples modified with either low or medium FA concentrations decreased in both dry and wet curing. In terms of mechanical strength, furfurylation had little effect on the macro- and micro-mechanical properties of bamboo and was slightly improved in comparison to untreated samples. The results also showed a positive correlation between the macro- and micro-mechanical strength of the modified bamboo samples and a significant negative correlation between the mechanical strength and ASE. In soaking impregnation, the WPG and ASE were positively correlated, while the WPG and CS were negatively correlated. Interestingly, the correlation between the mechanical properties and ASE was not significant. Finally, both V-P-Wet and S-Wet approaches can be recommended for bamboo furfurylation, the former being time-saving and having a high curing rate in FA resin while significantly improving the moisture absorption and mechanical strength of bamboo. The advantage of the latter process is simplicity, a high utilization rate of FA, and a significant improvement in the dimensional stability of bamboo. Full article

The lack of mutants due to the long periods between flowering of bamboo plants is one of the limiting factors inhibiting research progress in the culm development of bamboo plants. In this study, a stable new dwarf variant of Phyllostachys edulis (Moso bamboo), Phyllostachys edulis f. exaurita T. G. Chen, was discovered and was characterized morphologically, anatomically, and physiologically. The height, diameter at breast height, number of internodes, length and wall thickness of internodes, length, width and number of parenchyma cells of internodes, and morphology of the wide-type (WT) and dwarf variant vascular bundles were compared. The height of the variant was only 49% that of the WT Moso bamboo. It was concluded that the decrease in internode number and length was the cause of dwarfism in P. edulis f. exaurita. The decreased internode length was the result of a decrease in cell number and cell length in the internode. In addition, the laws of change of internode length, internode thickness, cell length, and cell number differed between the WT Moso bamboo and the variant. Furthermore, lower IAA and zeatin concentrations were detected in the buds of the variant. These results suggest that P. edulis f. exaurita is a variant with inhibited primary thickening growth, which is valuable for interpretating the molecular mechanisms underlying the primary thickening growth of bamboo that are still largely unknown. Full article