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1.
Article in English | MEDLINE | ID: mdl-38482615

ABSTRACT

BACKGROUND: Many studies have demonstrated that the expression of methyltransferase- like 3 (METTL3) is altered in various inflammatory diseases. Its specific mechanistic role in the intestinal inflammatory response during sepsis remains limited and requires further investigation. OBJECTIVES: Explore the potential mechanism of METTL3 in the intestinal inflammatory response during sepsis. MATERIALS AND METHODS: Immunohistochemical analysis was utilized to detect the expression of METTL3 in the necrotic intestine of patients with intestinal necrosis and the small intestine of cecal ligation and puncture (CLP) mice. Mice were subjected to the CLP and Sham surgeries, intestine tissue was harvested and performed HE staining, and ELISA to examine intestinal inflammatory responses, while TUNEL staining was applied to detect intestinal cell apoptosis. Additionally, ELISA was used to detect diamine oxidase (DAO) and intestinal fatty acid binding protein (I-FABP) levels in intestinal tissue. Immunohistochemistry and RT-qPCR were also employed to examine the mRNA and protein expression levels of Zona Occludens 1 (ZO-1) and Claudin-1. Finally, transcriptomic sequencing was performed on the small intestine tissues of METTL3 Knock-out (KO) and Wild-type (WT) mice in response to sepsis. RESULTS: METTL3 exhibited lower expression level in the necrotic intestine of patients and the small intestine of CLP mice. Loss of METTL3 in CLP mice triggered significantly higher expression of TNF-α and IL-18, down-regulated expression of ZO-1 and claudin-1, and decreased expression of DAO and I-FABP in the intestinal tissue. KEGG enrichment analysis showed that the differential genes were significantly enriched in immune-related pathways. CONCLUSION: This study reveals a novel mechanism responsible for exacerbated intestinal inflammation orchestrated by METTL3. Particularly, METTL3 null mice displayed decreased ZO- 1 and Claudin-1 expression, which largely hampered intestinal epithelial barrier function, resulting in bacterial and toxin translocation and intestinal immune activation and inflammation against sepsis.

2.
J Nutr Health Aging ; 28(2): 100017, 2024 02.
Article in English | MEDLINE | ID: mdl-38388115

ABSTRACT

BACKGROUND: The association between dietary habits and metabolic syndrome (MetS) has not been well documented, due to the complexity and individualization of dietary culture in the Chinese population. OBJECTIVE: To construct a composite score from various bad dietary habits and to evaluate their comprehensive association with the prevalence of MetS and its components among Chinese men and women across various age groups. SETTING: Serial cross-sectional studies. METHODS: Twenty-three dietary habits were assessed through face-to-face interviews with 98,838 males and 83,099 females in health check-up programs from 2015 to 2021, among which eighteen bad dietary habits were observed to be associated independently with total MetS. The total score of bad dietary habits was composed of four categories via variable clustering analysis, including irregular dietary habits, unhealthy dietary flavors, unbalanced dietary structure, and high-fat diet. The 2016 Chinese guideline for the management of dyslipidemia in adults was used to define MetS. RESULTS: Men had a higher score of bad dietary habits than women (9.63 ± 3.11 vs. 8.37 ± 3.23), which decreased significantly with increasing age in both males and females (Pinteraction<0.01). The prevalence of total MetS increased significantly with the cumulative score of bad dietary habits in both males (highest quintile vs. lowest quintile: OR, 1.90; 95% confidence interval [CI], 1.80-2.00; Plinear<0.01) and females (OR, 2.23; 95% CI, 2.02-2.46; Plinear<0.01) after adjusted for age, education, smoking status, alcohol consumption, and physical activities. These linear trends were also observed for each MetS component (all Plinear<0.01). The role of irregular dietary habits and high-fat diet on MetS prevalence are much higher in males than in females, while unhealthy dietary flavors and unbalanced dietary structure had a greater influence on females. CONCLUSIONS: The accumulation of bad dietary habits contributes to the MetS developments. Thus, individualized lifestyle interventions are needed to correct bad dietary habits with regard to gender differences.


Subject(s)
Diet , Metabolic Syndrome , Female , Humans , Male , Cross-Sectional Studies , Diet, High-Fat , Metabolic Syndrome/epidemiology , Metabolic Syndrome/etiology , Prevalence , Risk Factors , East Asian People
3.
Chem Commun (Camb) ; 59(71): 10672-10675, 2023 Aug 31.
Article in English | MEDLINE | ID: mdl-37581899

ABSTRACT

A series of seaweed-like heterogeneous Co3(PO4)2/Ni3(PO4)2/MOF-74-x electrocatalysts were synthesized via a hydrothermal method. The optimal composite exhibits excellent catalytic performance toward methanol/ethanol oxidation reactions (MOR/EOR) with peak current densities reaching 27.5 and 32.6 mA cm-2, respectively. This work heralds the advent of more efficient heterogeneous electrocatalysts for DAFCs and other energy conversion systems.

4.
J Environ Manage ; 333: 117466, 2023 May 01.
Article in English | MEDLINE | ID: mdl-36764181

ABSTRACT

Corn stover (CS) is a promising feedstock for producing biomethane, that can replace diminishing fossil fuels. However, the recalcitrant structure of CS resulted in low degradability in anaerobic digestion (AD). Numerous studies investigated the pretreatment of CS before AD, but the insight mechanism of biomethanation enhancement is not fully revealed. Therefore, this study advanced low-temperature urea-hydrothermal pretreatment of CS, and the biomethane production, substance bioconversion, hydrolase activity, and metagenomic analysis were conducted to unravel the intrinsic mechanisms of pretreatment for the enhanced biomethanation. The results showed that the pretreatment improved 11.5% of the specific surface area of CS, providing 111.5% higher total volatile fatty acids and 19.9% higher reducing sugars than the control, potentially enriching more anaerobic microorganisms. As a result, the pretreated CS achieved 19.1% higher biomethane yield, 9.1% higher volatile solid removal rate, and 3 days shorter digestion time. The mass balance and microbial community succession analysis indicated that the pretreatment reinforced the biomethane conversion from carbohydrate, which was attributed to the rapid enrichment of hydrolytic acidification bacteria (g__unclassified_o__Bacteroidales) (33.2%) and mixotrophic archaea (Methanosarcina) (72.3%). Meanwhile, the activity of cellulase and xylanase was enhanced up to 23.7% and 66.7%. Metagenomic analysis revealed that the combined pretreatment of CS promoted methanogenesis by enhancing various CAZymes secretion (such as oligosaccharide-degrading enzymes), and functional genes expression of hydrolytic, acidification and acetate-methane pathways at days 1-5. The study indicated that the combined pretreatment could influence microbial composition and function by changing the physicochemical properties of the CS, thereby improving methanogenic performance.


Subject(s)
Fatty Acids, Volatile , Zea mays , Anaerobiosis , Metagenome , Methane , Hydrolases , Bioreactors
5.
Front Physiol ; 13: 865442, 2022.
Article in English | MEDLINE | ID: mdl-35464080

ABSTRACT

In insects, metamorphosis is controlled by juvenile hormone (JH) and 20-hydroxyecdysone (20E). Krüppel homolog 1 (Kr-h1), a key JH-early inducible gene, is responsible for the suppression of metamorphosis and the regulation of the Broad-Complex (Br-C) gene, which is induced by 20E and functions as a "pupal specifier". In this study, we identified and characterized the expression patterns and tissue distribution of DaKr-h1 and DaBr-C at various developmental stages of Dendroctonus armandi. The expression of the two genes was induced by JH analog (JHA) methoprene and 20E, and their functions were investigated by RNA interference. DaKr-h1 and DaBr-C were predominantly expressed in the heads of larvae and were significantly downregulated during the molting stage. In contrast, the DaKr-h1 transcript level was highest in the adult anterior midgut. DaBr-C was mainly expressed in female adults, with the highest transcript levels in the ovaries. In the larval and pupal stages, both JHA and 20E significantly induced DaKr-h1, but only 20E significantly induced DaBr-C, indicating the importance of hormones in metamorphosis. DaKr-h1 knockdown in larvae upregulated DaBr-C expression, resulting in precocious metamorphosis from larvae to pupae and the formation of miniature pupae. DaKr-h1 knockdown in pupae suppressed DaBr-C expression, increased emergence, caused abnormal morphology, and caused the formation of small-winged adults. These results suggest that DaKr-h1 is required for the metamorphosis of D. armandi. Our findings provide insight into the roles of DaKr-h1 and DaBr-C in JH-induced transcriptional repression and highlight DaKr-h1 as a potential target for metamorphosis suppression in D. armandi.

6.
Int J Mol Sci ; 23(5)2022 Mar 02.
Article in English | MEDLINE | ID: mdl-35269892

ABSTRACT

Allatostatin C (PISCF/AST) is a neuropeptide gene that affects juvenile hormone (JH) synthesis in the corpora allata. Juvenile hormone acid O-methyltransferase (JHAMT) is a key gene in the JH biosynthetic pathway. In this study, two genes encoding DaAST and DaJHAMT were cloned. Both DaAST and DaJHAMT were expressed in the larvae, pupae and adults of Chinese white pine beetle (Dendroctonus armandi), and highly expressed in the head and the gut. The expression of the two genes was induced by JH analog (JHA) methoprene and the functions of the two genes were then investigated by RNAi. Considering the role of hormones in metamorphosis, JHA significantly induced DaAST and DaJHAMT in the larval stage. DaAST knockdown in larvae, pupae and adults significantly increased the DaJHAMT mRNA levels. Moreover, knockdown of DaAST instead of DaJHAMT increased pupae mortality and the abnormal rate of emergence morphology and reduced emergence rates. However, knockdown of DaJHAMT instead of DaAST significantly reduced frontalin biosynthesis in adult males. The results showed that DaAST acts as an allatostatin and inhibits JH biosynthesis, and that JHAMT is a key regulatory enzyme for JH synthesis in the D. armandi.


Subject(s)
Juvenile Hormones , Neuropeptides , Animals , Corpora Allata/metabolism , Juvenile Hormones/metabolism , Larva/metabolism , Male , Methyltransferases/genetics , Methyltransferases/metabolism , Neuropeptides/genetics , Neuropeptides/metabolism , Pupa/genetics , Pupa/metabolism
7.
Environ Entomol ; 51(1): 167-181, 2022 02 16.
Article in English | MEDLINE | ID: mdl-34897398

ABSTRACT

Dendroctonus armandi (Tsai and Li) (Coleoptera: Curculionidae: Scolytinae) is considered to be the most destructive forest pest in the Qinling and Bashan Mountains of China. Low winter temperatures limit insect's populations, distribution, activity, and development. Insects have developed different strategies such as freeze-tolerance and freeze-avoidance to survive in low temperature conditions. In the present study, we used gene cloning, real-time polymerase chain reaction (PCR), RNA interference (RNAi), and heterologous expression to study the function of the D. armandi antifreeze protein gene (DaAFP). We cloned the 800 bp full-length cDNA encoding 228 amino acids of DaAFP and analyzed its structure using bioinformatics analysis. The DaAFP amino acid sequence exhibited 24-86% similarity with other insect species. The expression of DaAFP was high in January and in the larvae, head, and midgut of D. armandi. In addition, the expression of DaAFP increased with decreasing temperature and increasing exposure time. RNAi analysis also demonstrated that AFP plays an important role in the cold tolerance of overwintering larvae. The thermal hysteresis and antifreeze activity assay of DaAFP and its mutants indicated that the more regular the DaAFP threonine-cystine-threonine (TXT) motif, the stronger the antifreeze activity. These results suggest that DaAFP plays an essential role as a biological cryoprotectant in overwintering D. armandi larvae and provides a theoretical basis for new pest control methods.


Subject(s)
Coleoptera , Weevils , Animals , Antifreeze Proteins/genetics , Antifreeze Proteins/metabolism , Cold-Shock Response , Coleoptera/genetics , Larva/genetics
8.
Front Chem ; 9: 780688, 2021.
Article in English | MEDLINE | ID: mdl-34912783

ABSTRACT

Engineering the heterogeneous interface fusing MOFs and inorganic active component is an effective strategy to improve the electrochemical performance. Herein, we report a new Ni3-based MOF (denoted as CTGU-24) with an infrequent two-fold interpenetrating 3D (3,8)-connected network constructed from Ni(II) trimer and mixed tripodal tectonics for the electrocatalytic methanol oxidation reaction (MOR). In order to improve its stability and activities, the heterogeneous hybrid CTGU-24@NiOOH has been fabricated successfully via the first preparation of the NiOOH nanosphere and then in situ formation of CTGU-24 decorated on the NiOOH surface. Moreover, the integration of CTGU-24@NiOOH and different additives [acetylene black (AB) and ketjen black (KB)], resulting in the optimized hybrid sample AB&CTGU-24@NiOOH (4:4). It attains better MOR performance with an area-specific peak current density of 34.53 mA·cm-2 than pure CTGU-24 (14.99 mA·cm-2) and improved durability in an alkali medium. The new findings indicate that the CTGU-24@NiOOH heterostructure formed in situ and the integration of moderate additives are critical to optimizing and improving electrocatalytic activity of pure MOF crystalline material.

9.
Front Physiol ; 12: 662651, 2021.
Article in English | MEDLINE | ID: mdl-34220532

ABSTRACT

Neuropeptide F (NPF) is an important signaling molecule that acts as a neuromodulator to regulate a diversity of physiological and behavioral processes from vertebrates to invertebrates by interaction with NPF receptors, which are G protein-coupled receptors (GPCR). However, nothing is known about NPF in Chinese white pine beetle, Dendroctonus armandi, a destructive pest of natural and coniferous forests in the middle Qinling Mountains of China. We have cloned and characterized cDNAs encoding one NPF precursor and two NPF receptors in D. armandi and made bioinformatics predictions according to the deduced amino acid sequences. They were highly similar to that of Dendroctonus ponderosa. The transcription levels of these genes were different between larvae and adults of sexes, and there were significant differences among the different developmental stages and tissues and between beetles under starvation and following re-feeding states. Additionally, downregulation of NPF and NPFR by injecting dsRNA into beetles reduced their food intake, caused increases of mortality and decreases of body weight, and also resulted in a decrease of glycogen and free fatty acid and an increase of trehalose. These results indicate that the NPF signaling pathway plays a significant positive role in the regulation of food intake and provides a potential target for the sustainable management of this pest.

10.
Arch Insect Biochem Physiol ; 107(4): e21828, 2021 Aug.
Article in English | MEDLINE | ID: mdl-34173689

ABSTRACT

The Chinese white pine beetle (Dendroctonus armandi Tsai and Li) is a significant pest of pine forests in the Qinling and Bashan Mountains of China. Adult males commonly produce frontalin using precursors synthesized through the mevalonate pathway, which is regulated by juvenile hormone III (JHIII). In this study, the expression levels of mevalonate pathway genes were quantified after phloem feeding and topical application of the JHIII solution. The frontalin was quantified by gas chromatography-mass spectrometry. Both the phloem feeding and JHIII treatments produced an evident upregulation in the male gut, mainly in 3-hydroxy-3-methylglutaryl-CoA synthase (HMGS) and 3-hydroxy-3-methylglutaryl-CoA reductase (HMGR). Moreover, HMGS, HMGR, isopentenyl diphosphate isomerase, and geranyl diphosphate synthase/farnesyl diphosphate synthase were upregulated in fed and JHIII-stimulated males of D. armandi under both conditions (solitary and paired). The expression levels were higher in paired compared to solitary males. Males had higher expression levels compared with females. Correspondingly, the phloem-feeding males produced more frontalin than JHIII-treated males, and the production of frontalin was higher in paired males than in solitary males. The knockdown of mevalonate pathway genes using RNAi in vivo effectively reduced the messenger RNA level of these genes and inhibited the production of frontalin. Among them, the silencing of HMGR or HMGS genes reduced the synthesis of frontalin most significantly.


Subject(s)
Bridged Bicyclo Compounds, Heterocyclic/metabolism , Mevalonic Acid/metabolism , Pheromones/biosynthesis , Weevils/metabolism , Animals , Female , Male , RNA Interference , Weevils/genetics
11.
ACS Appl Mater Interfaces ; 13(22): 26472-26481, 2021 Jun 09.
Article in English | MEDLINE | ID: mdl-34029052

ABSTRACT

Developing efficient metal-organic framework (MOF)-based electrocatalysts with improvable activity and persistence toward the methanol oxidation reaction (MOR) is attracting great research attention but still remains an enormous challenge. Herein, a facile strategy, hydrangea-shaped nickel hydroxide template-directed synthesis of the hierarchically structured Ni-MOF on the Ni(OH)2 heterocomposite (denoted as Ni-Ni) for efficient MOR, is developed. The unique hierarchical structure and synergistic effect of the heterocomposite afford more exposed active sites, a facile ion diffusion path, and improved conductivity, favorable for improving MOR catalytic performance. Remarkably, the optimized Ni-Ni-2 material delivers an excellent activity with a high peak current density (24.6 mA cm-2). Furthermore, to prove the universality of this strategy, NixCu1-x(OH)2 isometallic hydroxide was used as the precursor, and a series of MOF-74/CuxNi1-x(OH)2 (denoted as Ni-NiCu) heterogeneous materials have been prepared and could be used as an effective electrocatalyst to catalyze MOR. The results indicate that this strategy can be used in the synthesis of other new composite materials with specific hierarchical structures for a more efficient electrocatalytic system.

12.
Arch Insect Biochem Physiol ; 106(2): e21760, 2021 Feb.
Article in English | MEDLINE | ID: mdl-33231898

ABSTRACT

The Chinese white pine beetle Dendroctonus armandi (Tsai and Li) is a significant pest of the Qinling and Bashan Mountains pine forests of China. The Chinese white pine beetle can overcome the defences of Chinese white pine Pinus armandi (Franch) through pheromone-assisted aggregation that results in a mass attack of host trees. We isolated five full-length complementary DNAs encoding mevalonate pathway-related enzyme genes from the Chinese white pine beetle (D. armandi), which are acetoacetyl-CoA thiolase (AACT), geranylgeranyl diphosphate synthase (GGPPS), mevalonate kinase (MK), mevalonate diphosphate decarboxylase (MPDC), and phosphomevalonate kinase (PMK). Bioinformatic analyses were performed on the full-length deduced amino acid sequences. Differential expression of these five genes was observed between sexes, and within these significant differences among topically applied juvenile hormone III (JH III), fed on phloem of P. armandi, tissue distribution, and development stage. Mevalonate pathway genes expression were induced by JH III and feeding.


Subject(s)
Genes, Insect , Insect Proteins/genetics , Metabolic Networks and Pathways/genetics , Mevalonic Acid/metabolism , Transcriptome , Weevils/genetics , Amino Acid Sequence , Animals , Female , Insect Proteins/chemistry , Insect Proteins/metabolism , Larva/enzymology , Larva/growth & development , Male , Phylogeny , Pupa/enzymology , Pupa/growth & development , RNA, Messenger/genetics , RNA, Messenger/metabolism , Sequence Alignment , Weevils/enzymology , Weevils/growth & development
13.
Front Physiol ; 11: 546592, 2020.
Article in English | MEDLINE | ID: mdl-33281609

ABSTRACT

The Chinese white pine beetle (Dendroctonus armandi) is undoubtedly one of the most important pests causing ecological damage in the Qinling Mountains. When bark beetles invade conifers, they must overcome host tree defenses, including primary resistance and induced resistance responses. Moreover, this induced resistance occurs following herbivory by bark beetles. Bark beetles have a corresponding defense mechanism for degrading toxic compounds, and glutathione S-transferases (GSTs) can catalyze the binding of endogenous substances that reduce glutathione (GSH) to various harmful electrophilic substrates, increasing their solubility and facilitating their excretion from cells. In this experiment, we successfully obtained sixteen full-length sequences of D. armandi, which belonged to four GST categories (delta, epsilon, sigma, and theta). The transcript levels of sixteen GSTs in D. armandi were compared at four developmental stages (larvae, pupae, teneral adults, and adults), three different tissues (antennae, gut, and reproductive organs), and under various levels of terpenoid stimuli during feeding on phloem tissue to evaluate the various relevant modes of action. This study aids in the understanding of the interaction between monoterpenes and beetles, and beetles' detoxification through GSTs.

14.
Dalton Trans ; 49(42): 14854-14862, 2020 Nov 03.
Article in English | MEDLINE | ID: mdl-33057509

ABSTRACT

Designing novel multifunctional rare-earth metal-organic frameworks (MOFs) has attracted intensive attention. In particular, employing such materials for sensing or catalytic reactions is still very challenging. Here, a new 3D porous Eu(iii)-MOF, [Eu(cppa)(OH)]·xS (denoted as CTGU-19, S = solvent molecule, CTGU = China Three Gorges University), was synthesized by using 5-(4-carboxyphenyl)picolinic acid (H2cppa) as an organic ligand, and it shows a 3D (3,12)-connected topological net with the point symbol (420·628·818)(43)4, constructed from cubane-shaped tetranuclear europium building units. Interestingly, CTGU-19 can be used as a highly sensitive luminescent sensor to identify ornidazole (ODZ) and nitrofurantoin (NFT) at different excitation wavelengths. This result represents the first example of a lanthanide-metal-organic-framework (Eu-MOF) that can be employed as a discriminating fluorescent probe to recognize ODZ and NFT at different excitation wavelengths. Furthermore, after loading CTGU-19 with Ag and/or Au nanoparticles, the composites exhibit efficient catalytic performance for reducing 2-/3-/4-nitrophenols (2-/3-/4-NP), in which the unit mass reduction rate constants of Ag0.8Au0.2@CTGU-19 for 2-NP, 3-NP, and 4-NP reach 68.8, 53.80, and 52.34 s-1 g-1, respectively.

15.
Pest Manag Sci ; 76(1): 188-197, 2020 Jan.
Article in English | MEDLINE | ID: mdl-31106502

ABSTRACT

BACKGROUND: Insect pheromones and host volatiles are important for pest control due to their high efficiency and low potential for environmental pollution. The functions of myrtenol, myrtanol and myrtenal in pest-host interactions are unknown. This study aimed to determine the presence of myrtenol, myrtanol and myrtenal in newly emerged and emerged stages of Dendroctonus armandi, and in infected and healthy Pinus armandi, and to identify their roles in tree protection and pest management based on electroantennography (EAG), Y-tube and toxicity experiments. RESULTS: Gas chromatographic and mass spectrometry (GC-MS) analyses, EAG, Y-tube and toxicity assays revealed the following: (1) myrtenol was found in P. armandi phloem and did not exhibit significant toxicity towards D. armandi; (2) myrtanol was produced by infected P. armandi after D. armandi invasion and had significant toxicity towards D. armandi, especially females; and (3) myrtenal might represent an aggregation pheromone produced by female D. armandi to exert aggregation effects on other females, to help them overcome the resistance of P. armandi jointly and ensure a successful invasion, females remained in an aggregation state from leaving the host to mating in a new host. CONCLUSION: These findings suggest that myrtanol as a repellent has potential for the protection of P. armandi and that myrtenal could be used to trap and disorient D. armandi. © 2019 Society of Chemical Industry.


Subject(s)
Coleoptera , Pinus , Weevils , Animals , Bicyclic Monoterpenes , Female , Pheromones
16.
Front Physiol ; 10: 967, 2019.
Article in English | MEDLINE | ID: mdl-31427984

ABSTRACT

The ability to survive annual temperature minima could be a key determinant of distribution limits for insects under global climate change. Recent studies have suggested that insect aquaporins are indispensable for cellular water management under conditions that lead to dehydration and cold stress. Aquaporins are integral membrane water channel proteins in the major intrinsic protein superfamily and promote selected solutes and the movement of water across biological membranes. We cloned and characterized nine full-length aquaporins from Dendroctonus armandi (DaAqps), the most destructive forest pest in the Qinling Mountains of Shaanxi Province, China. Eight of the DaAqps belong to three classical aquaporin grades, including the Drosophila integral protein, the Pyrocoelia rufa integral protein, the entomoglyceroporins and one that belongs to the unorthodox grade of aquaporin 12-like channels. The DaAqps were increasingly expressed during different developmental stages and in different larval tissues, and expression peaked in mid-winter. They were tested under cold conditions for different lengths of time, and the expression of almost all DaAqps was down regulated with decreasing temperatures and long-term exposure to cold conditions. However, when the lowest temperatures were reached, the levels were immediately upregulated. These genes indicate that cold tolerance can improve through mortality responses at low temperatures after RNA interference of DaAqps. In our study, we analyzed the molecular response, expression patterns, and RNA interference of DaAqps and clarified the crucial role of protective compounds (aquaporins) underlying D. armandi cold tolerance and provide a new pest control method.

17.
Pest Manag Sci ; 75(4): 986-997, 2019 Apr.
Article in English | MEDLINE | ID: mdl-30204286

ABSTRACT

BACKGROUND: Bark beetles rely on detoxifying enzymes to resist the defensive terpenoids of their host trees. Research on carboxylesterases (CarEs) has focused on their multiple functions in the metabolic detoxification of pesticides and plant allelochemicals, drug resistance, and juvenile hormone and pheromone degradation. RESULT: We identified eight new CarE genes in the Chinese white pine beetle (Dendroctonus armandi) and carried out bioinformatics analysis on the deduced full-length amino acid sequences. Differential transcript levels of CarE genes were observed between sexes; within these levels, significant differences were found among the different development stages, and between insects fed on the phloem of Pinus armandi and exposed to five stimuli [(-)-α-pinene, (-)-ß-pinene, (+)-3-carene, limonene and turpentine] at 8 and 24 h. CONCLUSION: Transcription levels of CarE genes suggest some relationship with the detoxification of terpenoids released by host trees. The functions of bark beetle esterase are mainly in hydrolyzing the host chemical defense and degrading odorant molecules during host selection and colonization. © 2018 Society of Chemical Industry.


Subject(s)
Carboxylic Ester Hydrolases/genetics , Insect Proteins/genetics , Monoterpenes/metabolism , Pinus/chemistry , Weevils/genetics , Amino Acid Sequence , Animals , Carboxylic Ester Hydrolases/chemistry , Carboxylic Ester Hydrolases/metabolism , Female , Inactivation, Metabolic , Insect Proteins/chemistry , Insect Proteins/metabolism , Larva/enzymology , Larva/genetics , Larva/growth & development , Male , Phylogeny , Pupa/enzymology , Pupa/genetics , Pupa/growth & development , Sequence Alignment , Transcription, Genetic , Weevils/enzymology , Weevils/growth & development
18.
Front Physiol ; 9: 291, 2018.
Article in English | MEDLINE | ID: mdl-29636701

ABSTRACT

The Chinese white pine beetle, Dendroctonus armandi Tsai and Li (Coleoptera: Curculionidae: Scolytinae), is a serious pest of coniferous forests in China. Thus, there is considerable interest in developing eco-friendly pest-control methods, with the use of semiochemicals as a distinct possibility. Olfaction is extremely important for fitness of D. armandi because it is the primary mechanism through which the insect locates hosts and mates. Thus, here we characterized nine full-length genes encoding chemosensory proteins (CSPs) from D. armandi. The genes were ubiquitously and multiply expressed across different developmental stages and adult tissues, indicating various roles in developmental metamorphosis, olfaction, and gustation. Ligand-binding assays implied that DarmCSP2 may be the carrier of D. armandi pheromones and various plant host volatiles. These volatiles were identified through RNA interference of DarmCSP2 as: (+)-α-pinene, (+)-ß-pinene, (-)-ß-pinene, (+)-camphene, (+)-3-carene, and myrcene. The systematic chemosensory functional analysis of DarmCSP2 in this study clarified the molecular mechanisms underlying D. armandi olfaction and provided a theoretical foundation for eco-friendly pest control.

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