Exploration of invasive mechanisms via global ncRNA-associated virus-host crosstalk.

Viral infection is a complex pathogenesis and the underlying molecular mechanisms remain poorly understood. In this study, an integrated multiple resources analysis was performed and showed that the cellular ncRNAs and proteins targeted by viruses were primarily "hubs" and "bottlenecks" in the human ncRNA/protein-protein interaction. The common proteins targeted by both viral ncRNAs and proteins tended to skew toward higher degrees and betweenness compared with other proteins, showed significant enrichment in the cell death process. Specifically, >800 pairs of human cellular ncRNAs and viral ncRNAs that exhibited a high degree of functional homology were identified, representing potential ncRNA-mediated co-regulation patterns of viral invasion. Additionally, clustering analysis further revealed several distinct viral clusters with obvious functional divergence. Overall, this is the first attempt to systematically explore the invasive mechanism via global ncRNA-associated virus-host crosstalk. Our results provide useful information in comprehensively understanding the viral invasive mechanism.

[Reliability Study of Grating Coupled Semiconductor Laser Based on Raman Spectra Technique].

Grating coupled semiconductor lasers (GCSLs) has a wide application prospect in many fields, such as optical free space communication, intersatellite communication, ranging for laser radar, atmospheric environmental testing and medical imaging. In order to verify the reliability of GCSLs, the chips in different preparation stages and products of GCSLs are tested based on Raman spectroscopy. It concluded that for unprocessed semiconductor laser chip, the longitudinal optical (LO) photons mode vibration of GaAs chip is strong but the transverse (TO) optical photons mode vibration of GaAs chip is weak. when the is unprocessed. When the surface of GaAs chip is covered by a layer of SiO2 membrane, the LO mode will movetowards long wavelength direction, but its intensity wouldn't change. When a 100 m mesa is etched on GaAs chip which is covered by SiO2 membrane, LO mode vibration of GaAs chip weakens and TO mode vibration of GaAs chip enhances, and the peak width of LO mode and TO mode increase. After gratings are etched on the 100 m mesa, LO mode vibration of GaAs chip continues to weaken, but TO mode vibration of GaAs chip becomes stronger. It shows that lattice defects exist in the fabrication process of GCSLs. By contrast testson the semiconductor lasers without gratings, it shows that defect peaks present in the Raman spectrum of GCSLs regardless of the defects on light emitting surface. This further proved that the strains or defects were introduced into the fabrication process of grating structure, which affects its reliability, resulting in a decrease of the reliability of GCSLs.

[Resonance Raman Spectral Properties Studies of Beta-carotene in Solution].

Beta-carotene is an important kind of polyene biomolecules, which has significant applications on researching optoelectronic and functional materials. In-situ high pressure Raman spectra of beta-carotene are measured in CS2 solution and water respectively at pressure range from 0-0.60 GPa. Then we compared both of them the Raman shift and CC bond of the full width at half maximum (FWHM) of the Raman spectra. It is therefore concluded that both of the samples' Raman shift moved to the high wave number and the full width at half maximum increased depending of the pressure. The experiment phenomena were interpreted by the theory of "coherent weakly damped electronic-lattice vibration model" and "effective conjugation length model". The mechanism is that the beta-carotene is compressed and has the lower structure order, shorte the effective conjugation length, decreased Raman active, weaker the coherent weakly damping CC bond vibration in high pressure. Because of the CC bond length become short, so the Raman spectra are found to blueshift. The CC bond of the full width at half maximum (FWHM) of the Raman spectra increased is attributed to the increase of difference in C--C and C==C bond lengths. Moreover, due to dissolving in non-polar CS2 solvent, the beta-carotene encounters the interaction of the surrounding solvent molecules. So the dispersion force interaction between solute and solvent is more sensitive to pressure. Then it makes that the slop of Raman shift and the full width at half maximum in the CS2 solution are faster than dissolved in water with increasing pressure. This paper provides an application value for research on molecular structure change under the external field and the presence form of polyenes biomolecules in the solvent.

[Temperature characteristics of huang-Ryes factor of all-trans-beta-carotene].

A visible absorption and Raman spectra of all-trans-beta-beta-carotene was measured in cyclohexanol solution in the temperature range from 68 degrees C to 26 degrees C. The results indicated that the visible absorption spectra are red-shifted, Raman scattering cross section increases, Huang-Ryes factor and electron-phonon coupling constants of CC bond vibration modes decreases with the temperature decreasing. The changes are interpreted using the theory of "coherent weakly damped electronic-lattice vibration model" and "effective conjugation length model". The red shift of the absorption spectra and intensity of the Raman active are attributed to the thermal conformational change-induced increase in the effective conjugation length in all-trans-beta-carotene chains. All-trans-beta-carotene has strong coherent weakly damped CC bonds vibrational properties, which lead to large Raman scattering cross section in the solvent of low temperature. The electron-phonon coupling constants with dimension are used, which can easily establish relation with the Huang-Rhys factor and calculate the electron-phonon coupling constants of CC bond vibration modes. Effective conjugation length, the pi-electron delocalization range and the Raman scattering cross section are described by the electron-phonon coupling constants.

All-natural environmentally degradable poly (butylene terephthalate-co-caprolactone): A theoretical and experimental study of its degradation properties and mechanisms.

The design and production of materials with excellent mechanical properties and biodegradability face significant challenges. Poly (butylene terephthalate-co-caprolactone) copolyesters (PBTCL) is obtained by modifying the engineering plastic polybutylene terephthalate (PBT) with a simple one-pot process using readily biodegradable ε-caprolactone (ε-CL). The material has mechanical properties comparable to those of commercial biodegradable copolyester PBAT. Besides, this copolyester exhibited remarkable degradability in natural environments such as soil and ocean, for example, PBTCL1.91 lost >40 % of its weight after 6 months of immersion in the Bohai Sea. The effect and diversity of specific microorganisms acting on degradation in the ocean were analyzed by 16 s rDNA gene sequencing. Theoretical calculations such as Fukui function and DFT, and experimental studies on water-soluble intermediates and residual matrixes produced after degradation, confirmed that the insertion CL units not only act as active sites themselves susceptible to hydrolysis reactions, but also promote the reactivity of ester bonds between aromatic segments. This work provides insight for the development of novel materials with high performance and environmental degradability.

Enhanced degradation of poly(ethylene terephthalate) by the addition of lactic acid / glycolic acid: composting degradation, seawater degradation behavior and comparison of degradation mechanism.

The degradability improvement of poly(ethylene terephthalate) (PET), one of the most widely used but non-degradable disposable packaging material, is of great significance. However, the balance between degradability and mechanical properties remains a huge challenge. Herein, simple hydroxy acids, lactic acid (LA) and glycolic acid (GA) as easy hydrolysis sites were introduced into non-degradable PET via melt polycondensation. A series of high molecular weight poly(ethylene terephthalate-co-L­lactide) (PETL) and poly(ethylene terephthalate-co-glycolate) (PETG) copolyesters were synthesized with an excellent tensile strength greater than 50 MPa, much higher than that of most commercially available degradable polymers. The introduction of hydroxy acid endows PET with significantly improved composting and seawater degradation performance. Furtherly, the degradation rate of PETG with hydrophilic GA unit was faster than that of PETL, and the mineralization rate of PETG80 reaches 22.0%. The density of functional theory (DFT) calculation revealed that adding hydroxy acid to the PET molecular chain reduced the energy barrier of the hydrolysis reaction. The molecular polarity index (MPI) analysis furtherly confirmed that the higher affinity between the GA unit and water may be the primary reason for the faster degradation of PETG.

Fluorescence tracing the degradation process of biodegradable PBAT: Visualization and high sensitivity.

Biodegradable plastics have emerged as a potential solution to the mounting plastic pollution crisis. However, current methods for evaluating the degradation of these plastics are limited in detecting structural changes rapidly and accurately, particularly for PBAT, which contains worrying benzene rings. Inspired by the fact that the aggregation of conjugated groups can endow polymers with intrinsic fluorescence, this work found that PBAT emits a bright blue-green fluoresces under UV irradiation. More importantly, we pioneered a degradation evaluation approach to track the degradation process of PBAT via fluorescence. A blue shift of fluorescence wavelength as the thickness and molecular weight of PBAT film decreased during degradation in an alkali solution was observed. Additionally, the fluorescence intensity of the degradation solution increased gradually as the degradation progressed, and was found to be exponentially correlated with the concentration of benzene ring-containing degradation products following filtration with the correlation coefficient is up to 0.999. This study proposes a promising new strategy for monitoring the degradation process with visualization and high sensitivity.

Crustacean cardioactive peptide and its receptor modulate the ecdysis behavior in the pea aphid, Acyrthosiphon pisum.

Insects must undergo ecdysis for successful development and growth, in which crustacean cardioactive peptide (CCAP) is a master hormone. However, the function of CCAP signaling in pea aphid, Acyrthosiphon pisum, remains unclear. In this study, we determined the sequence of the CCAP precursor and its receptor in A. pisum. We identified the functional receptor ApCCAPR, and then expressed this receptor in Chinese hamster ovary (CHO) cells, which in consequence exhibited high sensitivity to the ApCCAP mature peptide. The ApCCAP transcript was detected in the central nervous system of A. pisum. Neurons containing CCAP were also identified by immunohistochemical staining against insect CCAP. RNAi silencing of ApCCAP or ApCCAP-R signals caused developmental failure during nymph-adult ecdysis. The dsRNA-treated fourth-instar nymphs could not shed their old cuticle and died. Taking these findings together, we conclude that ApCCAP, via the activation of ApCCAP-R, plays an essential role in regulating the process of nymph-adult ecdysis in A. pisum. Our results deepen our understanding of the regulation of early ecdysis in A. pisum.

An odorant-binding protein of Asian citrus psyllid, Diaphorina citri, participates in the response of host plant volatiles.

BACKGROUND: Odorant-binding proteins (OBPs) in insects contribute to the sensitivity of the olfactory system and connect external odorants to olfactory receptor neurons. Determination of the chemosensory functions in Diaphorina citri, a vector of the citrus Huanglongbing pathogen, may help in developing a potential target for pest management. RESULTS: Diaphorina citri showed dose-dependent electroantennogram recording (EAG) responses to 12 host plant volatiles. A two-choice behavioral trap experiment showed that four compounds (methyl salicylate, linalool, citral and R-(+)-limonene) that elicited high EAG responses also had significant attraction to adults. The expression profiles induced by these compounds were detected in nine OBP genes, DcitOBP1-9. DcitOBP3, DcitOBP6 and DcitOBP7 commonly showed significant upregulation or downregulation compared with the control. Microscale thermophoresis (MST) showed that the recombinant protein DcitOBP7 had high in vitro binding affinities (Kd < 10 µm) to methyl salicylate, linalool and R-(+)-limonene, and moderate binding affinity to citral with a Kd value of 15.95 µm. Furthermore, RNA interference (RNAi)-suppressed messenger RNA (mRNA) expression of DcitOBP7 resulted in a significant reduction in EAG activity and in adult D. citri behavioral responses to tested volatiles and the preferred host, Murraya paniculata. The hydrophilic residue Arg107 of DcitOBP7 may have a key role in binding odorants via formation of hydrogen bonds. CONCLUSION: These results show that DcitOBP7 plays an important role in the olfactory response. This finding may provide new insight into the functions of OBP families in D. citri and aid in the development of safe strategies for managing D. citri populations. © 2021 Society of Chemical Industry.

NADPH-cytochrome P450 reductase mediates the susceptibility of Asian citrus psyllid Diaphorina citri to imidacloprid and thiamethoxam.

BACKGROUND: The Asian citrus psyllid Diaphorina citri has developed high levels of resistance to many insecticides, and understanding its resistance mechanism will aid in the chemical control of this species. Nicotinamide adenine dinucleotide phosphate (NADPH)-cytochrome P450 reductase (CPR) is crucial in cytochrome P450 function, and in some insects CPR knockdown has increased their susceptibility to insecticides. However, the CPR from D. citri has not been characterized and its function is undescribed. RESULTS: The CPR gene of D. citri (DcCPR) was cloned and sequenced. The expression level of DcCPR, determined by reverse-transcription quantitative polymerase chain reaction (RT-qPCR) analysis, was highest in the midgut and in nymphs. After feeding on double-stranded RNA for 72 h, the DcCPR messenger RNA level in D. citri adults decreased by 68.4%, and the susceptibility of D. citri to imidacloprid and thiamethoxam significantly increased. Meanwhile, after DcCPR silencing, the specific activities of DcCPR protein and P450s were significantly reduced by 41.6% and 44.7%, respectively. The subsequent western blot analysis and quantification of band intensity also showed that DcCPR content significantly decreased, consistent with the results of the specific activity test. In a eukaryotic expression assay, the viability of cells expressing DcCPR was significantly higher than the viability of cells expressing green fluorescent protein (GFP) when cells were exposed to imidacloprid or thiamethoxam. CONCLUSION: These results indicate that DcCPR contributes to D. citri susceptibility to imidacloprid and thiamethoxam.

A Transcriptomic and Proteomic Analysis of the Diaphorina citri Salivary Glands Reveals Genes Responding to Candidatus Liberibacter asiaticus.

The Asian citrus psyllid (ACP), Diaphorina citri Kuwayama, is the principal vector of the Candidatus Liberibacter asiaticus (CLas) bacterium that causes Huanglongbing (HLB) disease. The D. citri salivary glands (SG) is an important barrier to the transmission of CLas. Despite its importance, the transcriptome and proteome of SG defense against CLas are unstudied in D. citri. In the present study, we generated a comparative transcriptome dataset of the SG in infected and uninfected D. citri using an Illumina RNA-Seq technology. We obtained 407 differentially expressed genes (DEGs), including 159 upregulated DEGs and 248 downregulated DEGs. Functional categories showed that many DEGs were associated with the ribosome, the insecticide resistance, the immune response and the digestion in comparison with CLas-infected SG and CLas-free SG. Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) databases confirmed that metabolism and immunity were important functions in the SG. Among the DEGs, 68 genes (35 upregulated and 33 downregulated) encoding putative-secreted proteins were obtained with a signal peptide, suggesting that these genes may play important roles in CLas infection. A total of 673 SG proteins were identified in uninfected D. citri by liquid chromatography-mass spectrometry/mass spectrometry (LC-MS/MS) analysis, and 30 DEGs (15 upregulated and 15 downregulated) were found using the local tBLASTP programs. Among the 30 DEGs, many DEGs mainly involved in the metabolism and cellular processes pathways. This study provides basic transcriptome and proteome information for the SG in D. citri, and helps illuminate the molecular interactions between CLas and D. citri.

Crustacean cardioactive peptide (CCAP) of the oriental fruit fly, Bactrocera dorsalis (Diptera: Tephritidae): Molecular characterization, distribution and its potential roles in larva-pupa ecdysis.

Insects must undergo ecdysis for successful development and growth, and the crustacean cardioactive peptide (CCAP) is one of the most important hormone in this process. Here we reported a cDNA encoding for the CCAP precursor cloned from the oriental fruit fly, Bactrocera dorsalis, a most destructive insect pest of agriculture. The CCAP mature peptide (PFCNAFTGC-NH2) of B. dorsalis was generated by post-translational processing and found to be highly comparable with other insects. RT-qPCR showed that mRNA of CCAP in B. dorsalis (BdCCAP) was predominantly expressed in the central nervous system (CNS) and midgut of 3rd-instar larvae. By using immunohistochemical analysis, we also localized the endocrine cells that produce CCAP in the CNS, ring gland and midgut of 3rd-instar larvae of B. dorsalis. The synthetic CCAP mature peptide could induce the expression of mRNA of adipokinetic hormone (AKH), the metabolic neuropeptides in insects. The expression of BdCCAP mRNA in the CNS, but not in the midgut, could be upregulated in the response to the challenge of insect molting hormone, 20-hydroxyecdysone.

The Ecdysis Triggering Hormone System, via ETH/ETHR-B, Is Essential for Successful Reproduction of a Major Pest Insect, Bactrocera dorsalis (Hendel).

Ecdysis triggering hormone (ETH), released by the Inka cells, is a master hormone in regulating the ecdysis process in insect. Here we investigated the presence and role of the ETH signaling in the female adult of the oriental fruit fly, Bactrocera dorsalis (Hendel) that is one of the most important invasive pest insects in agriculture worldwide. In the female adult, ETH was confirmed in the Inka cells at the tracheae by immunostaining and also in vitro exposure to ETH stimulated the isolated corpora allata of adult in activity. Then we prepared cDNA of females at 0, 5, 10, 15, and 20 days after adult eclosion, and RT-qPCR showed that the expression pattern of ETH and its receptor ETHR-B started from a peak at the day of adult eclosion (day 0), then dropped to basal levels and increased again between day 10 and 15 which is also the period corresponding to ovary growth. In contrast, ETHR-A was absent with Ct values of >33. The expression patterns of the ecdysteroid-producing Halloween genes Spook and Shade, and the vitellogenin genes Vg1, Vg2, and Vg3 co-occurred with peak levels at days 10-15, and also juvenile hormone acid methyltransferase (JHAMT) showed increased levels on day 15. Further in RNAi assays to better understand the role of ETH and ETHR, dsRNA was injected to adult and this led to a respective decrease in expression of 62 and 56% for ETH and ETHR-B, while ETHR-A stayed absent with Ct values of 33. In these RNAi-females, there was an apparently decreased expression for JHAMT and Vg2, together with a significant decrease of the JH titer and egg production. Injection of the JH mimetic methoprene could rescue Vg2 expression and egg production. Upstream, in dsETH/dsETHR-injected females, 20-hydroxyecdysone (20E) injection rescued the transcriptions of ETH and ETHR and also egg production. In summary, our results shed more light on the pivotal role that the ETH peptide hormone and its receptor ETHR-B play an essential role in the reproduction of the female adult of B. dorsalis, via the regulation of JH and vitellogenin, which are controlled by a pulse of 20E.