Design and Synthesis of MarinePolybrominated Diphenyl Ether Derivatives as Potential Anti-inflammatory Agents.

Natural polybrominated diphenyl ethers are generally isolated from sponges and possess a broad range of biological activities. Through screening of our marine natural product library, we discovered that polybrominated diphenyl ethers 5 and 6 exhibit considerable anti-inflammatory activity. In order to expand our repertoire of derivatives for further biological activity studies, we designed and synthesized a series of 5-related polybrominated diphenyl ethers. Importantly, compound 5a showed comparable anti-inflammatory activity while much lower cytotoxicity on lipopolysaccharide (LPS)-induced RAW264.7 cells. Additionally, western blotting analysis showed that 5a reduced the expression of phosphorylated extracellular signal-regulated kinase (p-ERK). Besides, molecular docking experiments were conducted to predict and elucidate the potential mechanisms underlying the varying anti-inflammatory activities exhibited by compounds 5a, 5, and 6.

Functional and Compositional Changes in Sirex noctilio Gut Microbiome in Different Habitats: Unraveling the Complexity of Invasive Adaptation.

The mutualistic symbiosis relationship between the gut microbiome and their insect hosts has attracted much scientific attention. The native woodwasp, Sirex nitobei, and the invasive European woodwasp, Sirex noctilio, are two pests that infest pines in northeastern China. Following its encounter with the native species, however, there is a lack of research on whether the gut microbiome of S. noctilio changed, what causes contributed to these alterations, and whether these changes were more conducive to invasive colonization. We used high-throughput and metatranscriptomic sequencing to investigate S. noctilio larval gut and frass from four sites where only S. noctilio and both two Sirex species and investigated the effects of environmental factors, biological interactions, and ecological processes on S. noctilio gut microbial community assembly. Amplicon sequencing of two Sirex species revealed differential patterns of bacterial and fungal composition and functional prediction. S. noctilio larval gut bacterial and fungal diversity was essentially higher in coexistence sites than in separate existence sites, and most of the larval gut bacterial and fungal community functional predictions were significantly different as well. Moreover, temperature and precipitation positively correlate with most of the highly abundant bacterial and fungal genera. Source-tracking analysis showed that S. noctilio larvae at coexistence sites remain dependent on adult gut transmission (vertical transmission) or recruitment to frass (horizontal transmission). Meanwhile, stochastic processes of drift and dispersal limitation also have important impacts on the assembly of S. noctilio larval gut microbiome, especially at coexistence sites. In summary, our results reveal the potential role of changes in S. noctilio larval gut microbiome in the successful colonization and better adaptation of the environment.

New Glycerolipids from the Traditional Chinese Medicine of Syngnathus acus (Hai-Long).

Two new glycerolipids, syngaculipids A and B (1 and 2), one first naturally occurring metabolite (8), together with five known compounds (3-7) were isolated from the AcOEt fraction of Syngnathus acus L. (Hai-Long). Their structures were elucidated by comprehensive spectral analyses involving UV, IR, MS, 1D and 2D NMR spectra and ECD calculations. All the isolated compounds were evaluated for their cytotoxicity against A549 and HCT-116 cell lines. Compound 8 exhibited moderate cytotoxicity with IC50 values of 34.5 and 38.9 µM on the A549 and HCT-116 cell lines, respectively.

Full-Length Transcriptome Sequencing-Based Analysis of Pinus sylvestris var. mongolica in Response to Sirex noctilio Venom.

Sirex noctilio is a major international quarantine pest that recently emerged in northeast China to specifically invade conifers. During female oviposition, venom is injected into the host together with its symbiotic fungus to alter the normal Pinus physiology and weaken or even kill the tree. In China, the Mongolian pine (Pinus sylvestris var. mongolica), an important wind-proof and sand-fixing species, is the unique host of S. noctilio. To explore the interplay between S. noctilio venom and Mongolian pine, we performed a transcriptome comparative analysis of a 10-year-old Mongolian pine after wounding and inoculation with S. noctilio venom. The analysis was performed at 12 h, 24 h and 72 h. PacBio ISO-seq was used and integrated with RNA-seq to construct an accurate full-length transcriptomic database. We obtained 52,963 high-precision unigenes, consisting of 48,654 (91.86%) unigenes that were BLASTed to known sequences in the public database and 4309 unigenes without any annotation information, which were presumed to be new genes. The number of differentially expressed genes (DEGs) increased with the treatment time, and the DEGs were most abundant at 72 h. A total of 706 inoculation-specific DEGs (475 upregulated and 231 downregulated) and 387 wounding-specific DEGs (183 upregulated and 204 downregulated) were identified compared with the control. Under venom stress, we identified 6 DEGs associated with reactive oxygen species (ROS) and 20 resistance genes in Mongolian pine. Overall, 52 transcription factors (TFs) were found under venom stress, 45 of which belonged to the AP2/ERF TF family and were upregulated. A total of 13 genes related to the photosystem, 3 genes related photo-regulation, and 9 TFs were identified under wounding stress. In conclusion, several novel putative genes were found in Mongolian pine by PacBio ISO seq. Meanwhile, we also identified various genes that were resistant to S. noctilio venom, such as GAPDH, GPX, CAT, FL2, CERK1, and HSP83A, etc.

Diversity-oriented synthesis of marine sponge derived hyrtioreticulins and their anti-inflammatory activities.

Diversity-oriented synthesis is aimed to increase the chemical diversity of target natural products for extensive biological activity evaluation. Indole ring is an important functional group in a large number of drugs and other biologically active agents, and indole-containing natural products have been frequently isolated from marine sources in recent years. In this paper, a series of indole-containing marine natural hyrtioreticulin derivatives, including 19 new ones, were designed, synthesized through a key Pictet-Spengler reaction, and evaluated for their inflammation related activity. Compound 13b displayed the most promising activity by inhibiting TNF-α cytokine release with an inhibitory rate of 92% at a concentration of 20 µmol·L-1. A preliminary structure-activity relationship analysis was also discussed. This research may throw light on the discovery of marine indole alkaloid derived anti-inflammatory drug leads.

Multilocus Genotyping and Intergenic Spacer Single Nucleotide Polymorphisms of Amylostereum areolatum (Russulales: Amylostereacea) Symbionts of Native and Non-Native Sirex Species.

Sirex noctilio along with its mutualistic fungal symbiont, Amylostereum areolatum (a white rot fungus), is an invasive pest that causes excessive damage to Pinus plantations in Northeast China. In 2015, S. noctilio were found to attack Pinus sylvestris var. mongolica, and often share larval habitat with the native woodwasp, S. nitobei. The objective of this study was to determine the possible origin(s) of the introduced pest complex in China and analyse the genetic diversity between A. areolatum isolated from invasive S. noctilio, native S. nitobei and other woodwasps collected from Europe (native range) and other countries. Phylogenetic analyses were performed using the intergenic spacer (IGS) dataset and the combined 4-locus dataset (the internal transcribed spacer region (ITS), translation elongation factor alpha 1 (tef1), DNA-directed ribosomal polymerase II (RPB2), and mitochondrial small subunit (mtSSU)) of three Amylostereum taxa. The multilocus genotyping of nuclear ribosomal regions and protein coding genes revealed at least three distinct multilocus genotypes (MLGs) of the fungus associated with invasive S. noctilio populations in Northeast China, which may have come from North America or Europe. The IGS region of A. areolatum carried by S. noctilio from China was designated type B1D2. Our results showed a lack of fidelity (the paradigm of obligate fidelity to a single fungus per wasp species) between woodwasp hosts and A. areolatum. We found that the native S. nitobei predominantly carried A. areolatum IGS-D2, but a low percentage of females instead carried A. areolatum IGS-B1D2 (MLG A13), which was presumably due to horizontal transmission from S. noctilio, during the sequential use of the same wood for larval development. The precise identification of the A. areolatum genotypes provides valuable insight into co-evolution between Siricidae and their symbionts, as well as understanding of the geographical origin and history of both Sirex species and their associated fungi.

A novel PGAM5 inhibitor LFHP-1c protects blood-brain barrier integrity in ischemic stroke.

Blood-brain barrier (BBB) damage after ischemia significantly influences stroke outcome. Compound LFHP-1c was previously discovered with neuroprotective role in stroke model, but its mechanism of action on protection of BBB disruption after stroke remains unknown. Here, we show that LFHP-1c, as a direct PGAM5 inhibitor, prevented BBB disruption after transient middle cerebral artery occlusion (tMCAO) in rats. Mechanistically, LFHP-1c binding with endothelial PGAM5 not only inhibited the PGAM5 phosphatase activity, but also reduced the interaction of PGAM5 with NRF2, which facilitated nuclear translocation of NRF2 to prevent BBB disruption from ischemia. Furthermore, LFHP-1c administration by targeting PGAM5 shows a trend toward reduced infarct volume, brain edema and neurological deficits in nonhuman primate Macaca fascicularis model with tMCAO. Thus, our study identifies compound LFHP-1c as a firstly direct PGAM5 inhibitor showing amelioration of ischemia-induced BBB disruption in vitro and in vivo, and provides a potentially therapeutics for brain ischemic stroke.

Proteo-Transcriptomic Characterization of Sirex nitobei (Hymenoptera: Siricidae) Venom.

The wood-boring woodwasp Sirex nitobei is a native pest in Asia, infecting and weakening the host trees in numerous ecological and commercial coniferous forest plantations. In China, hosts of S. nitobei are diverse, so the pest has spread to several provinces of China, resulting in considerable economic and ecological damage. During female oviposition, S. nitobei venom along with arthrospores of the symbiotic fungus Amylostereum areolatum or A. chaetica is injected into host trees, and the combination of these two biological factors causes the death of xylem host trees. The presence of venom alone causes only the yellowing and wilting of needles. In this study, we constructed the venom gland transcriptome of S. nitobei for the first time and a total of 15,036 unigenes were acquired. From the unigenes, 11,560 ORFs were identified and 537 encoding protein sequences with signal peptides at the N-terminus. Then, we used the venomics approach to characterize the venom composition of female S. nitobei and predicted 1095 proteins by liquid chromatography-tandem mass spectrometry (LC-MS/MS) analysis. We focused on seven proteins that were both highly expressed in the venom gland transcriptome and predicted in the crude venom proteome. These seven proteins are laccase-2, laccase-3, a protein belonging to the Kazal family, chitooligosaccharidolytic ß-N-acetylglucosaminidase, beta-galactosidase, icarapin-like protein, and waprin-Thr1-like protein. Using quantitative real-time PCR (qRT-PCR), we also proved that the genes related to these seven proteins are specifically expressed in the venom glands. Finally, we revealed the functional role of S. nitobei venom in the physiological response of host trees. It can not only promote the colonization of symbiotic fungus but contribute to the development of eggs and larvae. This study provides a deeper understanding of the molecular mechanism of the woodwasp-pine interaction.

Gut Structure and Microbial Communities in Sirex noctilio (Hymenoptera: Siricidae) and Their Predicted Contribution to Larval Nutrition.

The European woodwasp, Sirex noctilio Fabricius, is a major invasive quarantine pest that attacks and kills pine trees outside of its native range. Insect gut structure and gut microbiota play crucial roles in various life activities. Despite a few reports in nutrition and survival, an extensive study on the S. noctilio larval gut microbiome is lacking. We studied the gut structure using a stereo microscope and used high throughput sequencing of the bacterial 16S rRNA genes and fungal internal transcribed spacer 2 (ITS2) regions to investigate gut microbiota in different developmental stages of S. noctilio, including larvae, adults, and larval frass. We used PICRUSt2 to predict the functional profiles. The larval gut was thin and thread-like from the oral cavity to the anus, carrying few xylem particles in the crop. Pseudomonas, Ralstonia, and Burkholderia s.l were the dominant bacteria in the guts of larvae, adults, and frass, respectively. Even though Pseudomonas was the most abundant among all bacteria, Zoogloea, Ruminobacter, and Nitrosospira, which might be involved in degrading organic matter and fixing nitrogen occurred exclusively in the larval gut indicating their possible role in the growth and development of larvae in pine tree xylem. Fungal communities did not change significantly across different developmental stages or the frass. Amylostereum was dominant in the woodwasp's larval gut. Functional prediction of bacterial and fungal communities revealed that they may encod enzymes involved in degrading lignocellulose and fixing nitrogen. Ours is the first study that compares gut microbial communities present in S. noctilio larvae, adults, and frass. This study could provide an understanding of larval nutrient acquisition in nutrient-deficient host xylem to some extent. Our study may unlock novel strategies for the development of pest management approaches based on interfering with the gut microbiota and restricting their role in larval survival and development.

Medioresinol as a novel PGC-1α activator prevents pyroptosis of endothelial cells in ischemic stroke through PPARα-GOT1 axis.

AIM: Brain microvascular endothelial cells (BMVECs), as the important structure of blood-brain barrier (BBB), play a vital role in ischemic stroke. Pyroptosis of different cells in the brain may aggravate cerebral ischemic injury, and PGC-1α plays a major role in pyroptosis. However, it is not known whether BMVECs undergo pyroptosis after ischemic stroke and whether PGC-1α activator Medioresinol (MDN) we discovered may be useful against pyroptosis of endothelial cells and ischemic brain injury. METHODS: For in vitro experiments, the bEnd.3 cells and BMVECs under oxygen and glucose-deprivation (OGD) were treated with or without MDN, and the LDH release, tight junction protein degradation, GSDMD-NT membrane location and pyroptosis-associated proteins were evaluated. For in vivo experiments, mice underwent transient middle cerebral artery occlusion (tMCAO) for ischemia model, and the neuroprotective effects of MDN were measured by infarct volume, the permeability of BBB and pyroptosis of BMVECs. For mechanistic study, effects of MDN on the accumulation of phenylalanine, mitochondrial reactive oxygen species (mtROS) were tested by untargeted metabolomics and MitoSOX Red probe, respectively. RESULTS: BMVECs underwent pyroptosis after ischemia. MDN dose-dependently activated PGC-1α, significantly reduced pyroptosis, mtROS and the expressions of pyroptosis-associated proteins (NLRP3, ASC, cleaved caspase-1, IL-1ß, GSDMD-NT), and increased ZO-1 and Occludin protein expressions in BMVECs. In tMCAO mice, MDN remarkably reduced brain infarct volume and the permeability of BBB, inhibited pyroptosis of BMVECs, and promoted long-term neurobehavioral functional recovery. Mechanistically, MDN promoted the interaction of PGC-1α with PPARα to increase PPARα nuclear translocation and transcription activity, further increased the expression of GOT1 and PAH, resulting in enhanced phenylalanine metabolism to reduce the ischemia-caused phenylalanine accumulation and mtROS and further ameliorate pyroptosis of BMVECs. CONCLUSION: In this study, we for the first time discovered that pyroptosis of BMVECs was involved in the pathogenesis of ischemic stroke and MDN as a novel PGC-1α activator could ameliorate the pyroptosis of endothelial cells and ischemic brain injury, which might attribute to reduction of mtROS through PPARα/GOT1 axis in BMVECs. Taken together, targeting endothelial pyroptosis by MDN may provide alternative therapeutics for brain ischemic stroke.

A novel SIRT6 activator ameliorates neuroinflammation and ischemic brain injury via EZH2/FOXC1 axis.

Ischemic stroke is the second leading cause of death worldwide with limited medications and neuroinflammation was recognized as a critical player in the progression of stroke, but how to control the overactive neuroinflammation is still a long-standing challenge. Here, we designed a novel SIRT6 activator MDL-811 which remarkably inhibited inflammatory response in lipopolysaccharide (LPS)-stimulated RAW264.7 macrophages and primary mouse microglia, which were abolished by silencing SIRT6. RNA-seq screening identified the forkhead box C1 (Foxc1) is a key gene evoked by MDL-811 stimulation and is required for the anti-inflammatory effects of MDL-811. We found MDL-811-activated SIRT6 directly interacted with enhancer of zeste homolog 2 (EZH2) and promoted deacetylation of EZH2 which could bind to the promoter of Foxc1 and upregulate its expression to modulate inflammation. Moreover, our data demonstrated that MDL-811 not only ameliorated sickness behaviors in neuroinflammatory mice induced by LPS, but also markedly reduced the brain injury in ischemic stroke mice in addition to promoting long-term functional recovery. Importantly, MDL-811 also exhibited strong anti-inflammatory effects in human monocytes isolated from ischemic stroke patients, underlying an interesting translational perspective. Taken together, MDL-811 could be an alternative therapeutic candidate for ischemic stroke and other brain disorders associated with neuroinflammation.

The optimization of heterogeneous catalytic conditions in the direct alkylation of waste vegetable oil.

Alkylated waste vegetable oil is a versatile intermediate product in the synthesis of bio-based materials. Heterogeneous catalytic condition with high conversion rate in the direct alkylation of waste vegetable oil was reported and the deactivation mechanism of catalyst was revealed. The total exchange capacity, elemental composition and pyrolysis product of catalyst before and after the alkylation reaction were analysed by back titration, elemental analysis, electrospray ionization mass spectrometry, gas chromatography mass spectrometry and pyrolysis-gas chromatography/mass spectrometry, respectively. The results indicated that the metallic and non-metallic (C, H) elements contents of the catalyst have very much increased with great changes in pyrolysis product and a slight decrease in the total exchange capacity. The formation of insoluble polymers through Diels-Alder cycloaddition between triglycerides was proved to be the major factor causing the dysfunction of the catalytic centre. The metal ions from corrosion of the reactor were the minor factor causing about 2.56% loss of the catalytic centre. Moreover, the catalyst was able to maintain high catalytic efficiency when replacing the raw materials with other waste vegetable oil having low concentration of polyunsaturated fatty acids, which is significant for producing not only the aryl fatty acids derivatives but also the bio-based surfactants.

Pheromone biosynthetic pathway and chemoreception proteins in sex pheromone gland of Eogystia hippophaecolus.

The moth Eogystia hippophaecolus (Hua et al.) is a major threat to sea buckthorn plantations in China. Specific and highly efficient artificial sex pheromone traps have been developed and used to control this pest species. However, the biosynthesis of sex pheromones Z7-14: Ac and E3-14:Ac remains poorly understood. We investigated the female pheromone gland transcriptome of E. hippophaecolus and identified two pheromone biosynthesis-activating neuropeptides (PBANs), two pheromone biosynthesis-activating neuropeptide receptors (PBANrs), five acetyl-CoA carboxylases (ACCs), six fatty acid synthases (FASs), 16 Acyl-CoA desaturases (DESs), 26 reductases (REDs), 13 acetyltransferases (ACTs), one fatty acid transport protein (FATP), one acyl-CoA-binding protein (ACBP), and five elongation of very long-chain fatty acid proteins (ELOs) in pheromone biosynthesis pathways. Additionally, we identified 11 odorant-degrading enzymes (ODEs) and 16 odorant-binding proteins (OBPs), 14 chemosensory proteins (CSPs), two sensory neuron membrane proteins (SNMPs), three odorant receptors (ORs), seven ionotropic receptors (IRs), and six gustatory receptors (GRs). 77 unigenes involved in female pheromone biosynthesis, 31 chemoreception proteins and 11 odorant degradation enzymes were identified, which provided insight into the regulation of the pheromone components and pheromone recognition in the sex pheromone gland, and knowledge pertinent to new integrated pest management strategy of interference pheromone biosynthesis and recognition.

Comparison of Wing, Ovipositor, and Cornus Morphologies between Sirex noctilio and Sirex nitobei Using Geometric Morphometrics.

Sirex noctilio F. (Hymenoptera: Siricidae) is an invasive woodwasp from Europe and North Africa. Globalization has led to an expanding global presence in pine forests. S. noctilio has been previously introduced outside of its native range and now co-occurs in trees with native S. nitobei Matsumura (first discovered in 2016). Damage to Pinus sylvestris var. mongolica Litv in northeast China can be attributed to two types of woodwasp. To distinguish the two species by the traditional taxonomic morphology, we mainly differentiate the color of the male's abdomen and the female's leg. There remains intraspecific variation like leg color in the delimitation of related genera or sibling species of Sirex woodwasps. In this study, we used landmark-based geometric morphometrics including principal component analysis, canonical variate analysis, thin-plate splines, and cluster analysis to analyze and compare the wings, ovipositors, and cornus of two woodwasps to ascertain whether this approach is reliable for taxonomic studies of this group. The results showed significant differences in forewing venation and the shapes of pits in the middle of ovipositors among the two species, whereas little difference in hindwings and cornus was observed. This study assists in clarifying the taxonomic uncertainties of Siricidae and lays a foundation for further studies of the interspecific relationships of the genus Sirex.

Synthesis and Target Identification of Benzoxepane Derivatives as Potential Anti-Neuroinflammatory Agents for Ischemic Stroke.

Benzoxepane derivatives were designed and synthesized, and one hit compound emerged as being effective in vitro with low toxicity. In vivo, this hit compound ameliorated both sickness behavior through anti-inflammation in LPS-induced neuroinflammatory mice model and cerebral ischemic injury through anti-neuroinflammation in rats subjected to transient middle cerebral artery occlusion. Target fishing for the hit compound using photoaffinity probes led to identification of PKM2 as the target protein responsible for anti-inflammatory effect of the hit compound. Furthermore, the hit exhibited an anti-neuroinflammatory effect in vitro and in vivo by inhibiting PKM2-mediated glycolysis and NLRP3 activation, indicating PKM2 as a novel target for neuroinflammation and its related brain disorders. This hit compound has a better safety profile compared to shikonin, a reported PKM2 inhibitor, identifying it as a lead compound in targeting PKM2 for the treatment of inflammation-related diseases.

The Effect of Longwave Ultraviolet Light Radiation on Dendrolimus tabulaeformis Antioxidant and Detoxifying Enzymes.

Longwave ultraviolet (UVA) light, in the range of 315-400 nm, has been widely used as a light source in the light trapping of insect pests. Previous studies have demonstrated the oxidative stress and lethal effect of UV radiation on insects. In this study, we evaluated the influence of UVA radiation on the antioxidant and detoxifying enzymes of Dendrolimus tabulaeformis. We tested the contents of malondialdehyde (MDA), hydroxyl radical (·OH), hydrogen peroxide (H2O2), reduced glutathione (GSH), and oxidized glutathione (GSSH) following different exposure time periods of UVA light irradiation on D. tabulaeformis adults. In addition, we investigated how the activities of antioxidant and detoxifying enzymes responded to UVA radiation by determining the activities of superoxide dismutase (SOD), catalase (CAT), peroxidase (POD), polyphenol oxidase (PPO), glutathione S-transferase (GST), glutathione reductase (GR), acetylcholinesterase (AChE), carboxylesterase (CarE), alkaline phosphatase (ALP), and acid phosphatase (ACP). Adults were exposed to UVA light for different time periods (0, 5, 15, 30, 60, and 120 min). We found that exposure to UVA light for 5 min resulted in rapid variation in the activities of the antioxidant and detoxification enzyme systems. However, the antioxidant capacity of females was incongruous with that of males following UVA irradiation. Our results confirmed that UVA light irradiation increased the level of oxidative stress and disturbed physiological detoxification in D. tabulaeformis adults. Based on the above results, we anticipated that further research of the mechanism of UVA irradiation on the antioxidant and detoxifying enzymes of D. tabulaeformis would gain more importance, allowing to develop and use new, less toxic and environmentally friendly pesticides.

[Design and implementation of an automatic analysis system for magnetic resonance quality detection based on QT].

The quality inspection of magnetic resonance imaging (MRI) performance parameters is an important means to ensure the image quality and the reliability of diagnosis results. There are some problems in the manual calculation and eye recognition of the quality inspection parameters, such as strong subjectivity and low efficiency. In view of these facts, an automatic analysis system for MRI quality detection based on QT is proposed and implemented in C++ language. The image processing algorithm is introduced to automatically measure and calculate the quality inspection parameters. The software with comprehensive functions is designed to systematically manage the quality inspection information of MRI. The experimental results show that the automatically calculated parameters are consistent with the manually calculated ones. Accordingly, the accuracy and reliability of the algorithm is verified. The whole system is efficient, convenient and easy to operate, and it can meet the actual needs of MRI quality inspection.

Thermal survival limits of larvae and adults of Sirex noctilio (Hymenoptera: Siricidae) in China.

Temperature can be a major factor for the distribution of insects, especially among invasive insects. Sirex noctilio (Hymenoptera: Siricidae) has invaded many regions in China, causing enormous ecological and economic losses. We aimed to explore the trend and potential of diffusion by researching the thermal survival limits of S. noctilio. We measured the supercooling point (SCP), critical thermal temperature (CTmax), high lethal temperature (HLT) and low lethal temperature (LLT) for S. noctilio population in China and assessed life stage-related variation in thermal tolerance. Moreover, we determined the temperature tolerance range of S. noctilio and identified the temperature parameters for its potential invasive distribution risk analysis. The SCP of adults was -11.78 ± 0.67 (mean ± SEM), the CTmax was 37.67 ± 0.54, and those of larvae were -20.77 ± 0.44 and 40.53 ± 0.27, respectively. The LLT increased with exposure time, and the HLT was generally near 43°C. S. noctilio adults can tolerate higher temperatures than larvae, and the larvae showed high resistance to cold temperature. We calculated several temperature indexes based on our results, such as the lower temperature threshold (DV0) at -2.7°C, the upper temperature threshold (DV3) at 31°C, the temperature threshold for both heat stress (TTHS) at 35°C and cold stress (TTCS) at -32.5°C. We observed that, S. noctilio was not resistant to high temperatures, its CTmax is slightly lower than the lethal temperature, and the adults were more tolerant than larvae. Our next goal was to combine the temperature tolerance of symbiotic fungi, information on climate change and the current distribution of this species to predict its potential global distribution.

Effects of endophytic fungi diversity in different coniferous species on the colonization of Sirex noctilio (Hymenoptera: Siricidae).

Diversity of endophyte communities of the host tree affects the oviposition behavior of Sirex noctilio and the growth of its symbiotic fungus Amylostereum areolatum. In this study, we evaluated the structure and distribution of endophyte communities in the host tree (Pinus sylvestris var. mongolica) of S. noctilio and eight potential host tree species in China. Overall, 1626 fungal strains were identified by using internal transcribed spacer sequencing and morphological features. Each tree species harbored a fungal endophyte community with a unique structure, with the genus Trichoderma common to different communities. The isolation and colonization rate of endophytes from Pinus tabulaeformis, followed by P. sylvestris var. mongolica, were lower than those of other species. The proportion of endophytic fungi that strongly inhibited S. noctilio and symbiotic fungus growth was significantly lower in P. tabulaeformis, P. sylvestris var. mongolica and P. yunnanensis. Further, the diversity of the endophyte communities appeared to be predominantly influenced by tree species and the region, and, to a lesser extent, by the trunk height. Collectively, the data indicated that P. tabulaeformis might be at a higher risk of invasion and colonization by S. noctilio than other trees.

Sensilla on six olfactory organs of male Eogystia hippophaecolus (Lepidoptera: Cossidae).

Eogystia hippophaecolus (Hua et al.) is an important boring pest that primarily damages sea buckthorn, causing large ecological and economic damages in China. In this study, we used scanning electron microscopy to investigate the sensilla on six olfactory tissues of male E. hippophaecolus: antennae, labial palps, external genitals, propodeum, mesopodium, and metapedes. On the antennae, two types of sensillum trichodea, two types of sensillum basiconica, a type of sensillum coeloconica, and Böhm's bristles were found. The labial palps had sensilla trichodea and chaetica. On the external genitals, three types of sensilla trichodea were the only sensilla. Böhm bristles were found on the base of the tibia and at the terminus of the tarsus. Most sensilla were distributed on the tarsus of the three pairs of legs, and notably, a majority of which were sensilla trichodea and sensilla chaetica, were on the pretarsus and telotarsus of the three pairs of legs. In this study, the distribution, number, type, and morphology of the sensilla on six olfactory organs of E. hippophaecolus were determined, which established the foundation for a future immunohistochemical search of olfactory proteins. RESEARCH HIGHLIGHTS: Eogystia hippophaecolus is a serious pest of seabuckthorn. The distribution, number, type, and morphology of olfactory sensilla of E. hippophaecolus are determined. The function and distribution of sensilla are compared with those of other insects.