Odorant-binding protein 19 in Monochamus alternatus involved in the recognition of a volatile strongly emitted from ovipositing host pines.

Monochamus alternatus is the primary carrier of pine wood nematodes, which pose a serious threat to Pinus spp. in many countries. Newly emerging M. alternatus adults feed on heathy host pines, while matured adults transfer to stressed host pines for mating and oviposition. Several odorant-binding proteins (OBPs) of M. alternatus have been proved to aid in the complex process of host location. To clarify the corresponding relations between OBPs and pine volatiles, more OBPs need to be studied. In this research, MaltOBP19 showed a specific expression in the antennae and mouthparts of M. alternatus, and it was marked in 4 types of antenna sensilla by immunolocalization. Fluorescence binding assays demonstrated the high binding affinity of MaltOBP19 with camphene and myrcene in vitro. In Y-tube olfactory experiments, M. alternatus adults were attracted by camphene and RNAi of OBP19 via microinjection significantly decreased their attraction index. Myrcene induced phobotaxis, but RNAi had no significant effect on this behavior. Further, we found that ingesting dsOBP19 produced by a bacteria-expressed system with a newly constructed vector could lead to the knockdown of MaltOBP19. These results suggest that MaltOBP19 may play a role in the process of host conversion via the recognition of camphene, which has been identified to be strongly released in stressed host pines. In addition, it is proved that knockdown of OBP can be achieved by oral administration of bacteria-expressed double-stranded RNA in M. alternatus adults, providing a new perspective in the control of M. alternatus.

Analysis of DNA Methylation Differences during the JIII Formation of Bursaphelenchus xylophilus.

DNA methylation is a pivotal process that regulates gene expression and facilitates rapid adaptation to challenging environments. The pinewood nematode (PWN; Bursaphelenchus xylophilus), the causative agent of pine wilt disease, survives at low temperatures through third-stage dispersal juvenile, making it a major pathogen for pines in Asia. To comprehend the impact of DNA methylation on the formation and environmental adaptation of third-stage dispersal juvenile, we conducted whole-genome bisulfite sequencing and transcriptional sequencing on both the third-stage dispersal juvenile and three other propagative juvenile stages of PWN. Our findings revealed that the average methylation rate of cytosine in the samples ranged from 0.89% to 0.99%. Moreover, we observed significant DNA methylation changes in the third-stage dispersal juvenile and the second-stage propagative juvenile of PWN, including differentially methylated cytosine (DMCs, n = 435) and regions (DMRs, n = 72). In the joint analysis of methylation-associated transcription, we observed that 23 genes exhibited overlap between differentially methylated regions and differential gene expression during the formation of the third-stage dispersal juvenile of PWN. Further functional analysis of these genes revealed enrichment in processes related to lipid metabolism and fatty acid synthesis. These findings emphasize the significance of DNA methylation in the development of third-stage dispersal juvenile of PWN, as it regulates transcription to enhance the probability of rapid expansion in PWN.

Engineered pine endophytic Bacillus toyonensis with nematocidal and colonization abilities for pine wilt disease control.

Introduction: The pinewood nematode (PWN) is responsible for causing pine wilt disease (PWD), which has led to the significant decline of conifer species in Eurasian forests and has become a globally invasive quarantine pest. Manipulating plant-associated microbes to control nematodes is an important strategy for sustainable pest management. However, it has proven difficult to find pine-associated bacteria that possess both nematocidal activity and the ability to colonize pine tissues. Methods: The stress experiments with turpentine and pine tissue extract were carried out to screen for the desired target strain that could adapt to the internal environment of pine trees. This strain was used to construct an engineered nematocidal strain. Additionally, a fluorescent strain was constructed to determine its dispersal ability in Pinus massoniana seedlings through plate separation, PCR detection, and fluorescence microscopy observations. The engineered nematocidal strain was tested in the greenhouse experiment to assess its ability to effectively protect P. massoniana seedlings from nematode infection. Results: This study isolated a Bacillus toyonensis strain Bxy19 from the healthy pine stem, which showed exceptional tolerance in stress experiments. An engineered nematocidal strain Bxy19P3C6 was constructed, which expressed the Cry6Aa crystal protein and exhibited nematocidal activity. The fluorescent strain Bxy19GFP was also constructed and used to test its dispersal ability. It was observed to enter the needles of the seedlings through the stomata and colonize the vascular bundle after being sprayed on the seedlings. The strain was observed to colonize and spread in the tracheid after being injected into the stems. The strain could colonize the seedlings and persist for at least 50 days. Furthermore, the greenhouse experiments indicated that both spraying and injecting the engineered strain Bxy19P3C6 had considerable efficacy against nematode infection. Discussion: The evidence of the colonization ability and persistence of the strain in pine advances our understanding of the control and prediction of the colonization of exogenously delivered bacteria in pines. This study provides a promising approach for manipulating plant-associated bacteria and using Bt protein to control nematodes.

Transcriptomic response of Pinus massoniana to infection stress from the pine wood nematode Bursaphelenchus xylophilus.

The pinewood nematode (PWN) Bursaphelenchus xylophilus is a forestry quarantine pest and causes an extremely dangerous forest disease that is spreading worldwide. Due to the complex pathogenic factors of pine wood nematode disease, the pathogenesis is still unknown. B. xylophilus ultimately invades a host and causes death. However, little is known about the defence-regulating process of host pine after infection by B. xylophilus at the molecular level. Therefore, we wanted to understand how Pinus massoniana regulates its response to invasion by B. xylophilus. P. massoniana were artificially inoculated with B. xylophilus solution, while those without B. xylophilus solution were used as controls. P. massoniana inoculated with B. xylophilus solution for 0 h, 6 h, 24 h, and 120 h was subjected to high-throughput sequencing to obtain transcriptome data. At various time points (0 h, 6 h, 24 h, 120 h), gene transcription was measured in P. massoniana inoculated with PWN. At different time points, P. massoniana gene transcription differed significantly, with a response to early invasion by PWN. According to Gene Ontology (GO) classification and Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analysis, P. massoniana response to PWN invasion involves a wide range of genes, including plant hormone signal transformation, flavonoid biosynthesis, amino sugar and nucleoside sugar metabolism, and MAPK signalling pathways. Among them, inoculation for 120 hours had the greatest impact on differential genes. Subsequently, weighted gene coexpression network analysis (WGCNA) was used to analyse transcriptional regulation of P. massoniana after PWN infection. The results showed that the core gene module of P. massoniana responding to PWN was "MEmagenta", enriched in oxidative phosphorylation, amino sugar and nucleotide sugar metabolism, and the MAPK signalling pathway. MYB family transcription factors with the highest number of changes between infected and healthy pine trees accounted for 20.4% of the total differentially expressed transcription factors. To conclude, this study contributes to our understanding of the molecular mechanism of initial PWN infection of P. massoniana. Moreover, it provides some important background information on PWN pathogenic mechanisms.

Global diversity and biogeography of potential phytopathogenic fungi in a changing world.

Phytopathogenic fungi threaten global food security but the ecological drivers of their global diversity and biogeography remain unknown. Here, we construct and analyse a global atlas of potential phytopathogenic fungi from 20,312 samples across all continents and major oceanic island regions, eleven land cover types, and twelve habitat types. We show a peak in the diversity of phytopathogenic fungi in mid-latitude regions, in contrast to the latitudinal diversity gradients observed in aboveground organisms. Our study identifies climate as an important driver of the global distribution of phytopathogenic fungi, and our models suggest that their diversity and invasion potential will increase globally by 2100. Importantly, phytopathogen diversity will increase largely in forest (37.27-79.12%) and cropland (34.93-82.51%) ecosystems, and this becomes more pronounced under fossil-fuelled industry dependent future scenarios. Thus, we recommend improved biomonitoring in forests and croplands, and optimised sustainable development approaches to reduce potential threats from phytopathogenic fungi.

A Highly Expressed Antennae Odorant-Binding Protein Involved in Recognition of Herbivore-Induced Plant Volatiles in Dastarcus helophoroides.

Natural enemies such as parasitoids and parasites depend on sensitive olfactory to search for their specific hosts. Herbivore-induced plant volatiles (HIPVs) are vital components in providing host information for many natural enemies of herbivores. However, the olfactory-related proteins involved in the recognition of HIPVs are rarely reported. In this study, we established an exhaustive tissue and developmental expression profile of odorant-binding proteins (OBPs) from Dastarcus helophoroides, an essential natural enemy in the forestry ecosystem. Twenty DhelOBPs displayed various expression patterns in different organs and adult physiological states, suggesting a potential involvement in olfactory perception. In silico AlphaFold2-based modeling and molecular docking showed similar binding energies between six DhelOBPs (DhelOBP4, 5, 6, 14, 18, and 20) and HIPVs from Pinus massoniana. While in vitro fluorescence competitive binding assays showed only recombinant DhelOBP4, the most highly expressed in the antennae of emerging adults could bind to HIPVs with high binding affinities. RNAi-mediated behavioral assays indicated that DhelOBP4 was an essential functional protein for D. helophoroides adults recognizing two behaviorally attractive substances: p-cymene and γ-terpinene. Further binding conformation analyses revealed that Phe 54, Val 56, and Phe 71 might be the key binding sites for DhelOBP4 interacting with HIPVs. In conclusion, our results provide an essential molecular basis for the olfactory perception of D. helophoroides and reliable evidence for recognizing the HIPVs of natural enemies from insect OBPs' perspective.

High prevalence of taurodontism in North China and its relevant factors: a retrospective cohort study.

OBJECTIVE: The purpose of this study was to investigate the prevalence and relevant factors of taurodontism in North China. METHODS: We retrospectively analysed the cone beam computed tomography (CBCT) of 1025 patients (496 male and 529 female) aged between 10 and 59 years. The crown-body/root (CB/R) ratios of the maxillary and mandibular molars were measured. The prevalence of hypotaurodontism, mesotaurodontism, and hypertaurodontism was then calculated and the incidence of taurodontism along with its relevant factors, was evaluated. RESULTS: The overall rate of taurodontism in North China was as high as 78.9%. If the third molars (opsigenes) were excluded, which have a big morphological variation from each other, the rate was 52.4%. The mean CB/R ratio of taurodontism differs from tooth position: maxillary mandibular third molars > maxillary third molars > maxillary second molars > maxillary first molars > mandibular second molars > mandibular first molars (P < 0.05). In addition, the 1025 patients were divided into different age groups, and it was found that the mean CB/R ratio decreased with age (P < 0.05). Moreover, the CB/R ratio of the mandibular first and second molars in female patients was higher than males (P < 0.05). CONCLUSION: This study revealed that taurodontism is widely prevalent in North China. The incidence of taurodontism increases the closer the tooth is to the back end of the dental arch, and quite a few of the maxillary and mandibular third molars teeth have tapered roots. And the taurodontism is decreased by age, as there were more affected female than male patients.

Overexpression of salicylic acid methyltransferase reduces salicylic acid-mediated pathogen resistance in poplar.

Salicylic acid (SA) is generally considered to be a critical signal transduction factor in plant defenses against pathogens. It could be converted to methyl salicylate (MeSA) for remote signals by salicylic acid methyltransferase (SAMT) and converted back to SA by SA-binding protein 2 (SABP2). In order to verify the function of SAMT in poplar plants, we isolated the full-length cDNA sequence of PagSAMT from 84K poplar and cultivated PagSAMT overexpression lines (OE-2 isolate) to test its role in SA-mediated defenses against the virulent fungal pathogen Botryosphaeria dothidea. Our results showed that after inoculation with B. dothidea, OE-2 significantly increased MeSA content and reduced SA content which is associated with increased expression of SAMT in both infected and uninfected leaves, when compared against the wild type (WT). Additionally, SAMT overexpression plant lines (OE-2) exhibited higher expression of pathogenesis-related genes PR-1 and PR-5, but were still susceptible to B. dothidea suggesting that in poplar SA might be responsible for resistance against this pathogen. This study expands the current understanding of joint regulation of SAMT and SABP2 and the balance between SA and MeSA in poplar responses to pathogen invasion.

The Changes of Microbial Communities and Key Metabolites after Early Bursaphelenchus xylophilus Invasion of Pinus massoniana.

Pine wood nematode, Bursaphelenchus xylophilus, is a worldwide pest of pine trees, spreading at an alarming rate and with great ecological adaptability. In the process of causing disease, the nematode causes metabolic disorders and changes in the endophytic microbial community of the pine tree. However, the changes at the pine nidus during early nematode invasion have not been well studied, especially the differential metabolites, in Pinus massoniana, the main host of B. xylophilus in China. In this study, we analyzed the endophytic bacterial and fungal communities associated with healthy and B. xylophilus-caused wilted pine trees. The results show that 1333 bacterial OTUs and 502 fungal OTUs were annotated from P. massoniana stem samples. The abundance of bacterial communities in pine trees varies more following infection by B. xylophilus, but the abundance changes of fungal communities are less visible. There were significant differences in endophytic microbial diversity between wilted and healthy P. massoniana. In wilted pine trees, Actinobacteria and Bacteroidia were differential indicators of bacterial communities, whereas, in healthy pine trees, Rhizobiales in the Proteobacteria phylum were the major markers of bacterial communities. Meanwhile, the differential markers of fungal communities in healthy pines are Malasseziales, Tremellales, Sordariales, and Fusarium, whereas Pleosporaceae is the key marker of fungal communities in wilted pines. Our study examines the effect of changes in the endophytic microbial community on the health of pine trees that may be caused by B. xylophilus infection. In parallel, a non-targeted metabolomic study based on liquid mass spectrometry (LC-MS) technology was conducted on pine trees inoculated with pine nematodes and healthy pine trees with a view to identifying key compounds affecting early pine lesions. Ultimately, 307 distinctly different metabolites were identified. Among them, the riboflavin metabolic pathway in pine trees may play a key role in the early pathogenesis of pine wood nematode disease.

Identification of the Extracellular Nuclease Influencing Soaking RNA Interference Efficiency in Bursaphelenchus xylophilus.

RNA interference (RNAi) efficiency dramatically varies among different nematodes, which impacts research on their gene function and pest control. Bursaphelenchus xylophilus is a pine wood nematode in which RNAi-mediated gene silencing has unstable interference efficiency through soaking in dsRNA solutions, the factors of which remain unknown. Using agarose gel electrophoresis, we found that dsRNA can be degraded by nematode secretions in the soaking system which is responsible for the low RNAi efficiency. Based on the previously published genome and secretome data of B. xylophilus, 154 nucleases were screened including 11 extracellular nucleases which are potential factors reducing RNAi efficacy. To confirm the function of nucleases in RNAi efficiency, eight extracellular nuclease genes (BxyNuc1-8) were cloned in the genome. BxyNuc4, BxyNuc6 and BxyNuc7 can be upregulated in response to dsGFP, considered as the major nuclease performing dsRNA degradation. After soaking with the dsRNA of nucleases BxyNuc4/BxyNuc6/BxyNuc7 and Pat10 gene (ineffective in RNAi) simultaneously for 24 h, the expression of Pat10 gene decreased by 23.25%, 26.05% and 11.29%, respectively. With soaking for 36 h, the expression of Pat10 gene decreased by 43.25% and 33.25% in dsBxyNuc6+dsPat10 and dsBxyNuc7+dsPat10 groups, respectively. However, without dsPat10, dsBxyNuc7 alone could cause downregulation of Pat10 gene expression, while dsBxyNuc6 could not disturb this gene. In conclusion, the nuclease BxyNuc6 might be a major barrier to the RNAi efficiency in B. xylophilus.

Evolutionarily conserved odorant-binding proteins participate in establishing tritrophic interactions.

Attracting herbivores and their natural enemies is a standard method where plant volatiles mediate tritrophic interactions. However, it remains unknown whether the shared attraction has a shared chemosensory basis. Here we focus on the odorant-binding proteins (OBPs), a gene family integral to peripheral detection of odoriferous chemicals. Previous evidence suggests that the herbivorous beetle Monochamus alternatus and its parasitoid beetle Dastarcus helophoroides are attracted to stressed pines. In this study, (+)-fenchone, emitted by stressed pines, is found to be attracted to M. alternatus and D. helophoroides in behavioral assays. Meanwhile, two orthologous OBPs with a slower evolutionary rate, respectively, from the two insects are shown to bind with (+)-fenchone, and the attraction is abolished after RNAi. These results show the ability of evolutionarily conserved OBPs from herbivores and their enemies to detect the same plant volatiles, providing an olfactory mechanism of chemical signals-mediated tritrophic relationships.

Ho:LuAG single crystal fiber: growth, spectroscopy and laser characteristics.

Lutetium aluminum garnet single-crystal fiber (SCF, ∼ Φ 0.9 mm - 165 mm) doped with 0.5 at.% Ho3+ has been grown by the micro-pulling-down (µ-PD) technique. The room-temperature absorption and emission spectra exhibit similar features to the bulk crystal. Laser performances of the SCFs with two different pump configurations, i.e., pump guiding and free-space propagation, are studied by employing a 1.9-µm laser diode and a high-brightness fiber laser, respectively. Laser slope efficiencies obtained with both pump configurations can be higher than 50%, and a maximum output power of 6.01 W is achieved at ∼ 2.09 µm with the former pump. The comparable efficiency to the high-brightness pump is an indication of that high laser performance can also be expected through pump-guiding in the SCF even with a low pump beam quality.

A comparative study on the secretion of various cytokines by pulp stem cells at different passages and their neurogenic potential.

AIMS: By measuring the extent of cytokines secreted by human dental pulp stem cells (hDPSCs) from passages 2 through 10, the optimal passage of hDPSCs was determined. This offers a potential theoretical basis for the treatment of neurological disorders. METHOD: After isolation and culture of hDPSCs from human teeth, the morphological features of the cells were observed under an inverted microscope. hDPSCs were identified by their immunophenotypes and their multiple differentiation capability. Cytokine concentrations secreted in the supernatants at passages 2-10 were detected by ELISA. RESULTS: hDPSCs were viewed as fusiform or polygonal in shape, with a bulging cell body, homogenized cytoplasm, and a clear nucleus. Moreover, they could differentiate into neuroblasts in vitro. hDPSCs at passage 3 were positive for CD29 (91.5%), CD73 (94.8%) and CD90 (96.7%), but negative for the hematopoietic markers CD34 (0.13%). ELISA results showed that hDPSCs at passage 3 had the highest secretion levels of vascular endothelial growth factor (VEGF), brain-derived neurotrophic factor (BDNF), and nerve growth factor (NGF), with the highest secretion level of Neurotrophin-3 (NT-3) being at passage 2. CONCLUSION: hDPSCs have steady biological features of stem cells and exhibit optimal proliferation potential. hDPSCs at different passages have different capacities in the secretion of VEGF, BDNF, NGF, and NT-3. In conclusion cytokines secreted by hDPSCs may prove to be appropriate in the treatment of neurological diseases.

BarH1 regulates odorant-binding proteins expression and olfactory perception of Monochamus alternatus Hope.

Insect odorant-binding proteins (OBPs) are a class of small soluble proteins that can be found in various tissues wherein binding and transport of small molecules are required. Thus, OBPs are not only involved in typical olfactory function by specific activities with odorants but also participate in other physiological processes in non-chemosensory tissues. To better understand the complex biological functions of OBPs, it is necessary to study the transcriptional regulation of their expression patterns. In this paper, an apparent gradient expression pattern of Obp19, that was highly and specifically expressed in antennae and played an essential role in the detection of camphene, was defined in the antennae of the Japanese pine sawyer. Further, the transcription factor BarH1, that also presented gradient expression pattern in antennae, was found to regulate expression of Obp19 directly through binding to its upstream DNA sequence. The condition of BarH1 gene silence, the gene expression levels of Obp19 significantly decreased. At the same time, additional olfactory genes also were regulated and thus influence camphene reception. These findings provide us an opportunity to incorporate Obps in the gene regulatory networks of insects, which contribute to a better understanding of the multiplicity and diversity of OBPs and the olfactory mediated behaviors.

Differences Between Microbial Communities of Pinus Species Having Differing Level of Resistance to the Pine Wood Nematode.

The pine wood nematode (PWN), Bursaphelenchus xylophilus, is a destructive invasive species that exerts devastating effects on most native pines in invaded regions, while many of the non-native pines have resistance to PWN. Recently, increasingly more research is focused on how microbial communities can improve host resistance against pathogens. However, the relationship between the microbial community structures and varying levels of pathogen resistance observed in different pine tree species remains unclear. Here, the bacterial and fungal communities of introduced resistant pines Pinus elliottii, P. caribaea, and P. taeda and native susceptible pines healthy and wilted P. massoniana infected by PWN were analyzed. The results showed that 6057 bacterial and 3931 fungal OTUs were annotated. The pine samples shared 944 bacterial OTUs primarily in the phyla Proteobacteria, Acidobacteria, Firmicutes, Bacteroidetes, and Chloroflexi and 111 fungal OTUs primarily in phyla Ascomycota and Basidiomycota, though different pines had unique OTUs. There were significant differences in microbial community diversity between different pines, especially between the bacterial communities of resistant and susceptible pines, and fungal communities between healthy pines (resistant pines included) and the wilted P. massoniana. Resistant pines had a greater abundance of bacteria in the genera Acidothermus (class unidentified_Actinobacteria) and Prevotellaceae (class Alphaproteobacteria), but a lower abundance of Erwinia (class Gammaproteobacteria). Healthy pines had a higher fungal abundance of Cladosporium (class Dothideomycetes) and class Eurotiomycetes, but a lower abundance of Graphilbum, Sporothrix, Geosmithia (class Sordariomycetes), and Cryptoporus (classes Agaricomycetes and Saccharomycetes). These differences in microbial abundance between resistant and healthy pines might be associated with pathogen resistance of the pines, and the results of this study contribute to the studies exploring microbial-based control of PWN.

Identification and Functional Analysis of SlitOBP11 From Spodoptera litura.

Odorant binding proteins (OBPs) play a key role in the olfactory recognition of insects, whose functions have been extensively studied in adult insects but rarely in larvae. In this study, one OBP (SlitOBP11) with high expression in larval antenna but low expression in adult antenna of Spodoptera litura was screened by RNA-seq and verified by quantitative real-time PCR. Furthermore, the function of SlitOBP11 was explored by analysis of the expression patterns and prokaryotic expression of proteins as well as assays of competitive binding. Competitive binding assay demonstrated that SlitOBP11 had high binding affinity to all four female sex pheromone components, but exhibited almost no binding affinity to plant volatiles except for a low affinity to Phenylacetaldehyde and Phenethyl acetate. Homology modeling and molecular docking implied that the shape of these four sex pheromones were linear, which were appropriate for the binding channel of SlitOBP11 and the amino acid residue Asn99 of SlitOBP11 might play an important role in binding. Taken together, our results indicate that SlitOBP11 may be involved in the perception of female sex pheromones by S. litura larvae, and OBPs in the larvae of S. litura play an important role in the olfactory perception process.

Discovery of behaviorally active semiochemicals in Aenasius bambawalei using a reverse chemical ecology approach.

BACKGROUND: The invasive mealybug, Phenacoccus solenopsis, has caused serious damage to cotton crops throughout the world. Aenasius bambawalei is a dominant endoparasitoid of P. solenopsis. Exploration of behaviorally active semiochemicals may promote the efficacy of parasitoids used in biological control. Reverse chemical ecology, based on the physiological function of odorant-binding proteins (OBPs), provides an effective approach to screen behaviorally active compounds to target insect pests. Determination of the binding mechanisms and specificity towards different odorants in A. bambawalei may facilitate the development of more-efficient biological control strategies. RESULTS: We characterized the expression profile and analyzed the binding affinity of OBP28 in A. bambawalei. AbamOBP28 showed high expression in the wings and antennae of both male and female A. bambawalei. A fluorescence competitive binding assay indicated that AbamOBP28 displayed strong binding affinity to most candidate ligands. Circular dichroism spectra demonstrated that 1-octen-3-one, myrcene, dodecane, 2,4,4-trimethyl-2-pentene, nonanal, and limonene elicited conformational changes in AbamOBP28. Electrophysiological and behavioral bioassays revealed that diethyl sebacate, 2,4,4-trimethyl-2-pentene, and 1-octen-3-one evoked significant electroantennography responses and functioned as attractants in A. bambawalei at specific concentrations. Furthermore, three-dimensional structure modeling and molecular docking showed that hydrogen bonds were formed by Glu1 and Ser75 of AbamOBP28 with diethyl sebacate, respectively. CONCLUSION: These results demonstrate that AbamOBP28 is involved in the chemoreception of A. bambawalei. The identified protein provides a potential target for efficient enemy utilization and pest control, and the overall results may help develop protocols for more effective screening of behaviorally active semiochemicals. © 2021 Society of Chemical Industry.

Pinewood Nematode Alters the Endophytic and Rhizospheric Microbial Communities of Pinus massoniana.

Pinewood nematode, Bursaphelenchus xylophilus, is one of the greatest threats to pine trees and is spreading all over the world. During the nematode's pathogenesis, plant microorganisms play important roles. However, many microbial communities, such as that in Pinus massoniana, a major host of B. xylophilus that is widely distributed in China, are not well studied, especially the fungal communities. Here, the endophytic and rhizospheric bacterial and fungal communities associated with healthy and B. xylophilus-infected P. massoniana were analyzed. The results showed that 7639 bacterial and 3108 fungal OTUs were annotated from samples of P. massoniana, the rhizosphere, and B. xylophilus. There were significant diversity differences of endophytic microbes between healthy and infected P. massoniana. The abundances of endophytic bacteria Paenibacillus, unidentified_Burkholderiaceae, Serratia, Erwinia, and Pseudoxanthomonas and fungi Penicillifer, Zygoascus, Kirschsteiniothelia, Cyberlindnera, and Sporothrix in infected pines were greater than those in healthy pines, suggesting an association of particular microbial abundances with the pathogenesis of B. xylophilus in pines. Meanwhile, the abundances of microbes of unidentified_Burkholderiaceae, Saitozyma, and Pestalotiopsis were greater and Acidothermus and Trichoderma were lower in the rhizosphere under infected pines than those under healthy pines and the differences might be caused by B. xylophilus-induced weakening of the health of pines. Our study explored the endophytic and rhizospheric microbial community changes potentially caused by B. xylophilus infection of pines.

Functional Analysis of Two Odorant-Binding Proteins, MaltOBP9 and MaltOBP10, in Monochamus alternatus Hope.

Odorant-binding proteins (OBPs) are important for the perception of chemical signals by insects. Effective pest management strategies can be developed by understanding the host location mechanism and the physiological functions of OBPs in olfactory detection. In this study, we cloned two OBPs from Monochamus alternatus, where MaltOBP9 was highly expressed in multiple insect tissues and MaltOBP10 was highly expressed in the female antenna according to the results of qRT-PCR. The recombinant proteins were successfully purified in vitro. Immunocytochemistry indicated the high expression of MaltOBP9 and MaltOBP10 in the sensillum lymph of sensilla basiconica, sensilla trichodea, sensilla auricillica, and sensilla chaetica, thereby demonstrating their broad participation in semiochemical detection. Both proteins were localized in the inner cavity of mechanoreceptors and they exhibited broad binding abilities with volatiles from pine bark according to fluorescence competitive binding assays. Due to its broad binding ability and distribution, MaltOBP9 may be involved in various physiological processes as well as olfactory detection. MaltOBP10 appears to play a role in the fundamental olfactory recognition process of female adults according to its broad binding ability. These findings suggest that OBPs may have various physiological functions in insects, thereby providing novel insights into the olfactory receptive mechanism.

Knockdown of long non-coding RNA prostate cancer-associated transcript 1 inhibits the proliferation and metastasis of tongue squamous cell carcinoma cells by upregulating p21.

Long non-coding RNA (lncRNA) prostate cancer-associated transcript 1 (PCAT-1) is a long non-coding RNA involved in the development of various cancer types. Tongue squamous cell carcinoma (TSCC) is the most frequently diagnosed type of oral cancer worldwide. The present study aimed to explore the role of lncRNA PCAT-1 in TSCC, and to provide a preliminary assessment of the downstream pathways involved. The expression levels of lncRNA PCAT-1 in TSCC specimens were first assessed. Subsequently, lncRNA PCAT-1 was knocked down in TSCC cell lines and the resulting effect on the proliferation and apoptosis, as well as the metastatic and invasive potential of TSCC cells was investigated. To assess the downstream signaling resulting from lncRNA PCAT-1 inhibition, the expression of p21 was also detected. The results indicated that lncRNA PCAT-1 was upregulated in clinical TSCC compared with peri-tumor tissues. Inhibition of lncRNA PCAT-1 resulted in reduced proliferation and apoptosis of TSCC cells, in addition to the suppression of migration and invasion. Furthermore, the expression of p21 was induced following lncRNA PCAT-1 inhibition. Collectively, the present study demonstrated an oncogenic role for lncRNA PCAT-1 in TSCC; inhibition of lncRNA PCAT-1 reduced the growth, metastasis and invasion of TSCC, at least in part via the induction of p21 signaling.