Cyrtotrachelus Buqueti Research Articles

Global Distribution Prediction of Cyrtotrachelus buqueti Guer (Coleoptera: Curculionidae) Insights from the Optimised MaxEnt Model.

Cyrtotrachelus buqueti Guer is a major pest affecting bamboo forests economically, causing significant damage to bamboo forests in Sichuan Province, China. To understand how C. buqueti responds to future climate conditions, an optimized Maximum Entropy Model (Maxent) was used to simulate the potential global distribution patterns of C. buqueti under current climate conditions and three different future climate scenarios and to analyze the dominant factors influencing its distribution. The results indicate that Bio18 (precipitation of the warmest quarter), Bio04 (temperature seasonality), Bio06 (minimum temperature of the coldest month), and Bio02 (mean diurnal temperature range) are the main environmental factors affecting the distribution of this species. The global area of high-suitability habitats for C. buqueti is 9.00 × 104 km2, primarily distributed in China. Under three different future climate scenarios, there are varying degrees of expansion in both the total suitable habitat and the medium-suitability areas for C. buqueti. Under the SSP5-8.5 scenario, the medium-suitability area of the species increases the most, reaching 9.83 × 104 km2. Additionally, these findings can serve as a reference for developing and implementing control strategies, assisting relevant authorities in more effectively managing and controlling this pest, and mitigating its potential threats to bamboo forest ecosystems and economies.

Genome-wide identification and molecular evolution of elongation family of very long chain fatty acids proteins in Cyrtotrachelus buqueti

To reveal the molecular function of elongation family of very long chain fatty acids(ELO) protein in Cyrtotrachelus buqueti, we have identified 15 ELO proteins from C.buqueti genome. 15 CbuELO proteins were located on four chromosomes. Their isoelectric points ranged from 9.22 to 9.68, and they were alkaline. These CbuELO proteins were stable and hydrophobic. CbuELO proteins had transmembrane movement, and had multiple phosphorylation sites. The secondary structure of CbuELO proteins was mainly α-helix. A total of 10 conserved motifs were identified in CbuELO protein family. Phylogenetic analysis showed that molecular evolutionary relationships of ELO protein family between C. buqueti and Tribolium castaneum was the closest. Developmental transcriptome analysis indicated that CbuELO10, CbuELO13 and CbuELO02 genes were key enzyme genes that determine the synthesis of very long chain fatty acids in pupae and eggs, CbuELO6 and CbuELO7 were that in the male, and CbuELO8 and CbuELO11 were that in the larva. Transcriptome analysis under different temperature conditions indicated that CbuELO1, CbuELO5, CbuELO12 and CbuELO14 participated in regulating temperature stress responses. Transcriptome analysis at different feeding times showed CbuELO12 gene expression level in all feeding time periods was significant downregulation. The qRT-PCR experiment verified expression level changes of CbuELO gene family under different temperature and feeding time conditions. Protein-protein interaction analysis showed that 9 CbuELO proteins were related to each other, CbuELO1, CbuELO4 and CbuELO12 had more than one interaction relationship. These results lay a theoretical foundation for further studying its molecular function during growth and development of C. buqueti.

The Potential Distribution Prediction of the Forestry Pest Cyrtotrachelus buqueti (Guer) Based on the MaxEnt Model across China

Exploring the geographical distribution of forestry pests is crucial for formulating pest management strategies. Cyrtotrachelus buqueti (Guer) stands out as one of the primary pests among China’s forestry hazards. This study employs the MaxEnt model, along with 19 bioclimatic variables and habitat characteristics, to predict the current and future distribution of C. buqueti under three typical emission scenarios for 2050 and 2070 (2.6 W/m2 (SSP1-2.6), 7.0 W/m2 (SSP3-7.0), and 8.5 W/m2 (SSP5-8.5)). Among the 19 bioclimatic variables, BIO 14 (precipitation of the driest month), BIO 8 (mean temperature of the wettest quarter), Elev, slope, and aspect were identified as significant contributors. These five variables are critical environmental factors affecting the suitability of habitats for C. buqueti and are representative of its potential habitat. The results indicate that C. buqueti predominantly inhabits southern regions such as Chongqing, Guizhou, Yunnan, Sichuan, Guangxi, Shaanxi, Hubei, Hainan, and Taiwan. Among them, Chongqing, Guizhou, and Yunnan are the primary distribution areas of high suitability. In the future, the centroid’s movement direction will generally shift southward, with an expansion trend observed in the distribution areas of each province. This study enhances researchers’ understanding of forestry pest dynamics and promotes proactive management strategies to mitigate their impact on forest ecosystems and agricultural productivity.

Genome-wide identification, molecular evolution and gene expression of P450 gene family in Cyrtotrachelus buqueti

BackgroundInsect Cytochrome P450 monooxygenase (CYPs or P450s) plays an important role in detoxifying insecticides, causing insect populations to develop resistance. However, the molecular functions of P450 gene family in Cyrtotrachelus buqueti genome are still lacking.ResultsIn this study, 71 CbuP450 genes have been identified. The amino acids length of CbuP450 proteins was between 183 aa ~ 1041 aa. They are proteins with transmembrane domains. The main component of their secondary structure is α-helix and random coils. Phylogenetic analysis showed that C. buqueti and Rhynchophorus ferrugineus were the most closely related. This gene family has 29 high-frequency codons, which tend to use A/T bases and A/T ending codons. Gene expression analysis showed that CbuP450_23 in the female adult may play an important role on high temperature resistance, and CbuP450_17 in the larval may play an important role on low temperature tolerance. CbuP450_10, CbuP450_17, CbuP450_23, CbuP450_10, CbuP450_16, CbuP450_20, CbuP450_23 and CbuP450_ 29 may be related to the regulation of bamboo fiber degradation genes in C. buqueti. Protein interaction analysis indicates that most CbuP450 proteins are mainly divided into three aspects: encoding the biosynthesis of ecdysteroids, participating in the decomposition of synthetic insecticides, metabolizing insect hormones, and participating in the detoxification of compounds.ConclusionsWe systematically analyzed the gene and protein characteristics, gene expression, and protein interactions of CbuP450 gene family, revealing the key genes involved in the stress response of CbuP450 gene family in the resistance of C. buqueti to high or low temperature stress, and identified the key CbuP450 proteins involved in important life activity metabolism. These results provided a reference for further research on the function of P450 gene family in C. buqueti.

The Molecular and Functional Characterization of Sensory Neuron Membrane Protein 1b (SNMP1b) from Cyrtotrachelus buqueti (Coleoptera: Curculionidae).

Sensory neuron membrane proteins (SNMPs) play important roles in insect chemoreception and SNMP1s have been reported to be essential in detecting sex pheromones in Drosophila and some lepidopteran species. However, SNMPs for Cyrtotrachelus buqueti (Coleoptera: Curculionidae), a major insect pest of bamboo plantations, remain uncharacterized. In this study, a novel SNMP gene, CbuqSNMP1b, from C. buqueti was functionally characterized. The expression of CbuqSNMP1b was significantly higher in antennae than in other tissues of both sexes and the expression level was significantly male-biased. Additionally, CbuqSNMP1b showed significantly higher transcription levels in the adult stage and very low transcription levels in other stages, suggesting that CbuqSNMP1b is involved in the process of olfaction. Fluorescence binding assays indicated that CbuqSNMP1b displayed the strongest binding affinity to dibutyl phthalate (Ki = 9.03 μM) followed by benzothiazole (Ki = 11.59 μM) and phenol (Ki = 20.95 μM) among fourteen C. buqueti volatiles. Furthermore, molecular docking revealed key residues in CbuqSNMP1b that interact with dibutyl phthalate, benzothiazole, and phenol. In conclusion, these findings will lay a foundation to further understand the olfactory mechanisms of C. buqueti and promote the development of novel methods for controlling this pest.

Molecular and Functional Characterization of Pheromone Binding Protein 2 from Cyrtotrachelus buqueti (Coleoptera: Curculionidae)

Pheromone-binding proteins (PBPs) play important roles in binding and transporting sex pheromones. However, the PBP genes identified in coleopteran insects and their information sensing mechanism are largely unknown. Cyrtotrachelus buqueti (Coleoptera: Curculionidae) is a major insect pest of bamboo plantations. In this study, a novel PBP gene, CbuqPBP2, from C. buqueti was functionally characterized. CbuqPBP2 was more abundantly expressed in the antennae of both sexes than other body parts, and its expression level was significantly male-biased. Fluorescence competitive binding assays showed that CbuqPBP2 exhibited the strongest binding affinity to dibutyl phthalate (Ki = 6.32 μM), followed by styrene (Ki = 11.37 μM), among twelve C. buqueti volatiles. CbuqPBP2, on the other hand, showed high binding affinity to linalool (Ki = 10.55), the main volatile of host plant Neosinocalamus affinis. Furthermore, molecular docking also demonstrated the strong binding ability of CbuqPBP2 to dibutyl phthalate, styrene, and linalool, with binding energy values of −5.7, −6.6, and −6.0 kcal/mol, respectively, and hydrophobic interactions were the prevailing forces. The knockdown of CbuqPBP2 expression via RNA interference significantly reduced the electroantennography (EAG) responses of male adults to dibutyl phthalate and styrene. In conclusion, these results will be conducive to understanding the olfactory mechanisms of C. buqueti and promoting the development of novel strategies for controlling this insect pest.

Simultaneous saccharification and butanediol production from unpretreated lignocellulosic biomass using an enzymatic cocktail of a newly constructed bacterial consortium

Bioconversion lignocellulosic biomass (LCB) to 2,3-butanediol (2,3-BDO) is a sustainable and energy-intensive practice, but its economic feasibility has been hindered by costly pretreatment and the cumbersome fermentation process. Herein, the hindgut metagenome of Cyrtotrachelus buqueti is assembled and sequenced to construct bacterial consortia for efficient LCB degradation. One of these consortia, named artificial synthetic bacteria community II (ASCII), is effective in degrading unpretreated LCB, achieving degradation rates of 85.33% for cellulose, 77.43% for hemicellulose, and 57.63% for lignin. The secretory protein extracted from ASCII is used for simultaneous saccharification and fermentation (SSF) from unpretreated LCB. Furthermore, fed-batch SSF resulted in 40.62 g/L of 2,3-BDO with a productivity of 0.42 g/L/h reached by Klebsiella sp. CQHG35. This study provides a new approach for the construction of bacterial consortia and their use in SSF for the production of 2,3-BDO from unpretreated LCB, representing a significant breakthrough in this field.

Integrative microbial and transcriptomic analysis reveals the lignocellulosic biomass degrading mechanism by bamboo snout beetle

Insects and gut symbiotic bacteria have shown promise in the degradation of lignocellulosic biomass (LCB). Cyrtotrachelus buqueti is being studied as a resource for LCB degradation, but its mechanisms are not fully understood. This study investigates the host transcriptome and gut microbiome to identify the inherent mechanisms behind efficient LCB degradation. The gut secretory protein showed degradation rates of 30.23%− 38.24% for cellulose, 58.56%− 70.96% for hemicellulose, and 28.71%− 43.43% for lignin, while microbiota had degradation rates of 28.41%− 38.31% for cellulose, 53.45%− 66.15% for hemicellulose, and 25.65%− 38.37% for lignin. Core genera (>80%) of bacteria are identified in the foregut, midgut, and hindgut, with the hindgut containing the most abundant lignin degradation potential genera Serratia and Dysgonomonas, and the midgut has the highest abundance of cellulose and hemicellulose degradation likely genera Lactococcus and Enterococcus. The transcriptome reveals highly abundant and diversified lignocellulolytic genes encoding carbohydrate-active enzymes (CAZymes), with lignin-modifying enzyme genes highly expressed in the hindgut and cellulase and hemicellulase genes highly expressed in the foregut and midgut. Integrative analysis reveals a significant correlation between the gut microbiome and transcriptome, contributing to efficient LCB degradation. This study first provides a deeply comprehensive insight into the unique mechanisms of LCB degradation by C. buqueti.

Design optimization of lightweight structures inspired by the rostrum in Cyrtotrachelus buqueti Guer (Coleoptera: Curculionidae)

The rostrum of Cyrtotrachelus buqueti Guer has excellent mechanical properties, such as high-specific strength and high-specific stiffness, and it is an example of successful evolution in nature. In this paper, based on the biological structural characteristics of the rostrum, bionic variable-density lightweight structures of varying layer number are designed, and their mechanical properties are analyzed under different helix angles. The results show that when the helix angle is greater than or equal to 40°, the maximum compressive load borne by the three-layer tube is 30.75 N, which is 1.89 times that of the single-layer tube. Through calculation, at a helix angle of 15°, the torsion lightweight coefficient of the single-layer, double-layer, and three-layer structures is 0.99 ± 0.03 N·M g−1, 1.75 ± 0.05 N·M g−1, and 2.32 ± 0.06 N·M g−1, respectively, where that of the three-layer structure was approximately 2.34 times that of the single-layer structure. Further calculations show that the bending lightweight factor of the single-layer, double-layer, and three-layer tubes is 17.89 ± 0.20 N g−1, 33.16 ± 0.45 N g−1, 41.33 ± 0.55 N g−1, respectively, where that of the three-layer tube is 2.31 times that of the single-layer tube. In addition, this paper also investigates the cushioning energy absorption characteristics of the bionic lightweight tubes by using an impact testing machine. The results show that under the same conditions, as the number of layers of the lightweight tube increases, the buffering energy absorption also increases. The total energy absorption and specific energy absorption of the three-layer lightweight tube are approximately 10 times those of the single-layer tube. Finally, a response surface-based optimization method is proposed to optimize the bionic structures under a combined compression-torsion load. The results lay the foundation for the lightweight design of thin-walled tube structures.

Functional characteristics of the rigid elytra in a bamboo weevil beetle Cyrtotrachelus buqueti.

The bamboo weevil beetle, Cyrtotrachelus buqueti, has evolved a particular flight pattern. When crawling, the beetle folds the flexible hind wings and stuffs under the rigid elytra. During flight, the hind wings are deployed through a series of deployment joints that are passively driven by flapping forces. When the hind wings are fully expanded, the unfolding joint realises self‐locking. At this time, the hind wings act as a folded wing membrane and flap simultaneously with the elytra to generate aerodynamics. The functional characteristics of the elytra of the bamboo weevil beetle were investigated, including microscopic morphology, kinematic properties and aerodynamic forces of the elytra. In particular, the flapping kinematics of the elytra were measured using high‐speed cameras and reconstructed using a modified direct linear transformation algorithm. Although the elytra are passively flapped by the flapping of the hind wings, the analysis shows that its flapping wing trajectory is a double figure‐eight pattern with flapping amplitude and angle of attack. The results show that the passive flapping of elytra produces aerodynamic forces that cannot be ignored. The kinematics of the elytra suggest that this beetle may use well‐known flapping mechanisms such as a delayed stall and clap and fling.

Mathematical model and nanoindentation properties of the claws of Cyrtotrachelus buqueti Guer (Coleoptera: Curculionidae).

Scanning electron microscopy (SEM) was used to observe the macroscopic, microscopic, and cross‐sectional structures of the claws of Cyrtotrachelus buqueti Guer (Coleoptera: Curculionidae), and a mathematical model of a claw was used to investigate the structure–function relationships. To improve the quality of the SEM images, a non‐local means (NLM) algorithm and an improved NLM algorithm were applied. After comparison and analysis of five classical edge‐detection algorithms, the boundaries of the structural features of the claw were extracted based on a B‐spline wavelet algorithm, and the results showed that the variable curvature of the beetle claw enhances its adhesion force and improves its strength. Adhesion models of the claw were established, and the mechanical properties of its biomaterials were measured using nanoindentation. Considering that the presence of water can affect the hardness and Young's modulus, both ‘dry’ and ‘wet’ samples were examined. For the dry samples, the hardness and Young's modulus were 0.197 ± 0.074 GPa and 1.105 ± 0.197 GPa, respectively, whereas the respective values for the wet samples were both lower at 0.071 ± 0.030 GPa and 0.693 ± 0.163 GPa. This study provides data that can inform the design of climbing robots.

Integrated Analysis of Metabolome and Transcriptome of Bambusa emeiensis Shoots in Response to Bamboo Snout Beetle Cyrtotrachelus buqueti (Coleoptera: Curculionidae)

Plants have evolved constitutive and inductive defense mechanisms to protect themselves from herbivorous insects. Metabolites in plants are thought to be involved in response to herbivores. Bambusa emeiensis is an important bamboo species widely distributed in Southwest China. It is easy to attract herbivores such as Cyrtotrachelus buqueti. Through the detection and analysis of metabolites in B. emeiensis metabolomic data, 35 differential metabolites (biomarkers) were finally identified from 206 detection peaks, mainly primary metabolites. Subsequently, we conducted an association analysis between 35 biomarkers that annotated to be involved in 71 metabolic pathways in the metabolome and 324 differentially expressed genes (DEGs) in 207 gene expression pathways distributed in the transcriptome of B. emeiensis after feeding by C. buqueti. We also discussed the relationship between the changes in gene expression levels and metabolite content variation. A total of 47 integrated pathways containing the corresponding DEGs and biomarkers were screened out, with the amino acid synthesis pathway (ko01230) containing the most DEGs and biomarkers. In these integrated pathways, the changes in biomarkers content and the expression levels of the corresponding genes were generally consistent. For example, the increase in tryptophan content was accompanied by an increase in the expression of the corresponding catalase in the tryptophan synthesis pathway. Similar to this was glucose and trehalose in carbohydrate metabolism. Therefore, this study further deepened our understanding of the defense mechanism of B. emeiensis against bamboo pests and provided new insights for the prevention and control of bamboo diseases and pests.

Chromosome-Level Genome Assembly of Cyrtotrachelus buqueti and Mining of Its Specific Genes

Background:The most severe insect damage to bamboo shoots is the bamboo-snout beetle (Cyrtotrachelus buqueti). Bamboo is a perennial plant that has significant economic value.C. buquetialso plays a vital role in the degradation of bamboo lignocellulose and causing damage. The genome sequencing and functional gene annotation ofC. buquetiare of great significance to reveal the molecular mechanism of its efficient degradation of bamboo fiber and the development of the bamboo industry.Results:The size ofC. buquetigenome was close to 600.92 Mb by building a one paired-end (PE) library and k-mer analysis. Then, we developed nine 20-kb SMRTbell libraries for genome sequencing and got a total of 51.12 Gb of the original PacBio sequel reads. Furthermore, after filtering with a coverage depth of 85.06×, clean reads with 48.71 Gb were obtained. The final size ofC. buquetigenome is 633.85 Mb after being assembled and measured, and the contig N50 ofC. buquetigenome is 27.93 Mb. The value of contig N50 shows that the assembly quality ofC. buquetigenome exceeds that of most published insect genomes. The size of the gene sequence located on chromosomes reaches 630.86 Mb, accounting for 99.53% of the genome sequence. A 1,063 conserved genes were collected at this assembled genome, comprising 99.72% of the overall genes with 1,066 using the Benchmark Uniform Single-Copy Orthology (BUSCO). Moreover, 63.78% of theC. buquetigenome is repetitive, and 57.15% is redundant with long-term elements. A 12,569 protein-coding genes distributed on 12 chromosomes were acquired after function annotation, of which 96.18% were functional genes. The comparative genomic analysis results revealed thatC. buquetiwas similar toD. ponderosae.Moreover, the comparative analysis of specific genes inC. buquetigenome showed that it had 244 unique lignocellulose degradation genes and 240 genes related to energy production and conversion. At the same time, 73P450genes and 30GSTgenes were identified, respectively, in theC. buquetigenome.Conclusion:The high-qualityC. buquetigenome has been obtained in the present study. The assembly level of this insect’s genome is higher than that of other most reported insects’ genomes. The phylogenetic analysis ofP450andGSTgene family showed thatC. buquetihad a vital detoxification function to plant chemical components.

Mathematical Model and microCT-Based Kinematic Analysis of the Rostrum Mouthparts in Cyrtotrachelus buqueti Guer (Coleoptera: Curculionidae).

To uncover the chewing mechanism of Cyrtotrachelus buqueti Guer, a mathematical model was created and a kinematic analysis of its rostrum mouthparts was conducted for, to our knowledge, the first time. To reduce noise and improve the quality of scanning electron micrographs of the weevil's mouthparts, nonlocal means and integral nonlocal means algorithms were proposed. Additionally, based on a comparison and analysis of five classical edge detection algorithms, a multiscale edge detection algorithm based on the B-spline wavelet was used to obtain the boundaries of structural features. The least squares method was used to analyze the data of the mouthparts to fit the mathematical model and fitted curves were obtained using Gaussian equations. The results show that curvature and concave-convex variations of the weevil's mouthparts can highlight fluctuations in friction effects when it chews bamboo shoots, which is helpful in preventing debris from bamboo shoots or other debris from sticking to the mouthpart surfaces. Moreover, this paper highlights the utility of micro-computed tomography (microCT) for three-dimensional (3D) reconstruction and a flowchart is suggested. The reconstructed slices were 9.0 μm thick and an accurate 3D rendered model was obtained from a series of microCT slices. Finally, a real model of the rostrum mouthparts was analyzed using finite-element analysis. The results provide a biological template for the design of a novel bionic drilling mechanism.

Design of Bionic Foldable Wing Mimicking the Hind Wings of theC. BuquetiBamboo Weevil

AbstractThe bamboo weevil, Cyrtotrachelus buqueti, has excellent flight ability and strong environmental adaptability. When it flies, its fore wings and hind wings are unfolded, whereas when it crawls, its fore wings are closed, and its flexible hind wings are regularly folded under the fore wings. In this paper, the hind wing folding/unfolding pattern of C. buqueti is analyzed and a new bionic foldable wing with rigid–flexible coupling consisting of a link mechanism and a wing membrane is constructed. The movement of the link at the wing base mimics the contraction of a muscle in the thorax that triggers scissor-like motion and the deployment of the veins. Elastic hinges are used to mimic the rotational motion of the wing base and the vein joints. The static/dynamic characteristics of bionic foldable wings are further analyzed, and the LS-DYNA software is used to investigate rigid–flexible coupling dynamics. The elastic deformation of the wing membrane, kinematic characteristics of the linkage mechanism, and modes of the whole system are calculated. Static analysis of the structure reveals that the foldable wing has excellent stiffness characteristics and load-bearing capacity. The bionic foldable wing is constructed using three-dimensional (3D) printing technology, and its folding and unfolding performance is tested. Evaluation of its performance shows that the bionic wing has a large fold ratio and can achieve stable folding and unfolding motions. A slightly tighter assembly between the pin and the hinge hole ensures that the wing does not fold back during flapping.

Morphological Structures of Bamboo (Bambusa emeiensis) Shoot Shells and Trichomes and Functions in Response to Herbivory

Bamboo (Bambusa emeiensis) shoot, a nutritious food, easily attracts herbivores, including the bamboo weevil, Cyrtotrachelus buqueti. Scanning electron microscopy revealed that bamboo shoot shells (BSSs), the protective layers encasing bamboo shoots, are composed of closely packed fibers and bamboo shoot trichomes (BSTs) are divided into three types, including glandular trichome I, and non-glandular types II and III. To elucidate the underlying molecular defense mechanisms, 50 transcription factors (TFs) were chosen for qRT-PCR analyses of BSS and BST based on bamboo shoot transcriptome data. Among these, 8 and 23 genes were significantly differentially expressed in BSS and BST, respectively, indicating that BSS and BST responded to herbivory. BSS and non-glandular BST functioned as physical barriers and glandular BST released volatile compounds in defense against herbivory. Some TFs might act as mediators and participate in defense responses by BSS and BST.

Karyotype Analysis of Cyrtotrachelus buqueti Guer

Taking the testis of male adults of Cyrtotrachelus buqueti Guer as the experimental materials, the chromosome number and morphology of C. buqueti were observed by acetic acid magenta tabletting method, and the karyotype characteristics were analyzed in this study. The results showed that the chromosome number of C. buqueti was 2n = 22, including 10 pairs of autosomes and 1 pair of sex chromosomes, all of which were centromeres of middle/sub middle, NF = 22. The sex determination mechanism of C. buqueti was Xyp type, and the karyotype formula was 2n = 22 = 16m + 4sm + Xyp. The percentage of chromosome with the longest chromosome to the shortest chromosome ratio greater than 4∶1, and the percentage of chromosome with the arm ratio greater than 2∶1 was 0.1. So the karyotype of C. buqueti was 2C type, and no secondary constriction and satellite characteristics were observed. The results supplemented the blank of the basic research on the classification characteristics of C. buqueti chromosome.

Transcriptome-wide identification, classification, and characterization of NAC family genes in Bamboo Bambusa emeiensis

The NAC (NAM-ATAF1/2-CUC) transcription factors (TFs) regulate numerous biological processes, such as growth, development, and stress responses. The yield and quality of Bambusa emeiensis, an economically important bamboo, decrease under stress caused by insect herbivores, such as Cyrtotrachelus buqueti. In the present study, 33 BeNACs, including 4 membrane-associated TFs, were identified in B. emeiensis transcriptome. Phylogenetic analysis revealed that BeNACs and their Arabidopsis thaliana counterparts clustered into 4 major groups, which were subdivided into 17 subgroups. Conserved motif and phylogenetic analyses revealed that BeNACs with close evolutionary relationships contained highly similar motifs. The N-terminal regions of BeNACs had NAC domains. In addition, the C-termini and transmembrane domains of four BeNACs contained transmembrane motifs. Transcriptome analysis revealed that majority of BeNACs were highly expressed under herbivory. The expression levels of eight BeNACs, including predicted stress-related and membrane-bound BeNACs, in bamboo shoots, shells, trichomes, and leaves and under two treatments (fed and unfed) were assessed through quantitative real-time polymerase chain reaction. Several BeNACs (BeNAC4, 10, 19, and 24) were considered as closely related to responses to herbivore. This study lays a foundation for future study of BeNACs’ functions in bamboo development and stress response.

Plant carbohydrate‐active enzymes in bamboo Neosinocalamus affinis: identification, classification and function in lignocellulose biosynthesis in herbivore defence

Neosinocalamus affinis, a type of cluster bamboo, is a good candidate feedstock for biomass energy. In this study, we identified 686 genes as members of CAZyme families in the N. affinis transcriptome. These genes included 222 glycoside hydrolases (GHs), 288 glycosyltransferases (GTs), 64 carbohydrate esterases (CEs), 70 auxiliary activities (AAs), 37 carbohydrate binding modules (CBMs) and five polysaccharide lyases (PLs). Expression profile analysis revealed that several CAZyme genes, particularly GT, GH, AA and CE family members, were up‐regulated after insect infestation. Lignocellulose assays showed that the contents of three components, namely, cellulose, hemicellulose and lignin, increased after insect infestation. CAZyme genes were abundant in the N. affinis transcriptome and were involved in herbivory response. These findings could be applied to the protection of bamboo against herbivores, such as the bamboo snout beetle Cyrtotrachelus buqueti, and in the development of low‐cost chemical feedstock from bamboo.

Genome sequencing of gut symbiotic Bacillus velezensis LC1 for\xa0bioethanol production from bamboo shoots

BackgroundBamboo, a lignocellulosic feedstock, is considered as a potentially excellent raw material and evaluated for lignocellulose degradation and bioethanol production, with a focus on using physical and chemical pre-treatment. However, studies reporting the biodegradation of bamboo lignocellulose using microbes such as bacteria and fungi are scarce.ResultsIn the present study, Bacillus velezensis LC1 was isolated from Cyrtotrachelus buqueti, in which the symbiotic bacteria exhibited lignocellulose degradation ability and cellulase activities. We performed genome sequencing of B. velezensis LC1, which has a 3929,782-bp ring chromosome and 46.5% GC content. The total gene length was 3,502,596 bp using gene prediction, and the GC contents were 47.29% and 40.04% in the gene and intergene regions, respectively. The genome contains 4018 coding DNA sequences, and all have been assigned predicted functions. Carbohydrate-active enzyme annotation identified 136 genes annotated to CAZy families, including GH, GTs, CEs, PLs, AAs and CBMs. Genes involved in lignocellulose degradation were identified. After a 6-day treatment, the bamboo shoot cellulose degradation efficiency reached 39.32%, and the hydrolysate was subjected to ethanol fermentation with Saccharomyces cerevisiae and Escherichia coli KO11, yielding 7.2 g/L of ethanol at 96 h.ConclusionsThese findings provide an insight for B. velezensis strains in converting lignocellulose into ethanol. B. velezensis LC1, a symbiotic bacteria, can potentially degrade bamboo lignocellulose components and further transformation to ethanol, and expand the bamboo lignocellulosic bioethanol production.