RESUMO
Cadmium (Cd) is a heavy metal that is of great concern in agroecosystems due to its toxicity to plants, herbivores, carnivores, and human beings. The current study evaluated the allocation and bioaccumulation of Cd from soil to cotton plants, cotton plants to herbivore pests, and herbivorous pests to a natural enemy predator. When soil was spiked with 100 mg/kg Cd, results demonstrated that cotton roots accumulated more Cd than the stems and leaves. The bioaccumulation of Cd was less in 4th instar larvae, pupa, and adults of Serangium japonicum than in Bemisia tabaci adults. The bioaccumulation in S. japonicum elongated the immature development period and reduced adult longevity, oviposition days, fertility, and total pre-oviposition duration. The net reproduction of S. japonicum was also reduced, as was female mature weight and feeding potential; as a result, Cd exposure could reduce the future population size compared to uncontaminated populations. There was decreased activity of the antioxidant enzymes (SOD, CAT, and POD) and energy-conserving lipids (glycogen, triglyceride, and total cholesterol) in Cd-contaminated S. japonicum compared to controls. The detoxifying enzyme activity of GST and P450 increased while AChE activity did not change. The qRT-PCR research showed that SOD1, CAT, POD, glycogen, and triglyceride gene expression was higher than in controls, whereas detoxification gene expression did not change. Our results indicate that Cd exposure has a physiological trade-off between its adverse effects on life history traits and elevated detoxification and antioxidation of S. japonicum, which could result from gene expression alteration. Further studies are needed to assess whether Cd exposure causes irreversible DNA damage in S. japonicum.
Assuntos
Besouros , Hemípteros , Humanos , Animais , Feminino , Besouros/fisiologia , Cádmio , Antioxidantes , Glicogênio , Solo , TriglicerídeosRESUMO
In this study, a new species of the subgenus Pullus belonging to the Scymnus genus from Pakistan, Scymnus (Pullus) cardi sp. nov., was described and illustrated, with information on its distribution, host plants, and prey. Additionally, the completed mitochondrial genome (mitogenome) of the new species using high-throughput sequencing technology was obtained. The genome contains the typical 37 genes (13 protein-coding genes, two ribosomal RNAs, and 22 transfer RNAs) and a non-coding control region, and is arranged in the same order as that of the putative ancestor of beetles. The AT content of the mitogenome is approximately 85.1%, with AT skew and GC skew of 0.05 and -0.43, respectively. The calculated values of relative synonymous codon usage (RSCU) determine that the codon UUA (L) has the highest frequency. Furthermore, we explored the phylogenetic relationship among 59 representatives of the Coccinellidae using Bayesian inference and maximum likelihood methods, the results of which strongly support the monophyly of Coccinellinae. The phylogenetic results positioned Scymnus (Pullus) cardi in a well-supported clade with Scymnus (Pullus) loewii and Scymnus (Pullus) rubricaudus within the genus Scymnus and the tribe Scymnini. The mitochondrial sequence of S. (P.) cardi will contribute to the mitochondrial genome database and provide helpful information for the identification and phylogeny of Coccinellidae.
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Cardinium and Wolbachia are maternally inherited bacterial symbionts of arthropods that can manipulate host reproduction by increasing the fitness of infected females. Here, we report that Cardinium and Wolbachia coinfection induced male-killing and cytoplasmic incompatibility (CI) when they coexisted in a cryptic species of whitefly, Bemisia tabaci Asia II7. Cardinium and Wolbachia symbionts were either singly or simultaneously localized in the bacteriocytes placed in the abdomen of B. tabaci nymphs and adults. Cardinium-Wolbachia coinfection induced male-killing and resulted in a higher female sex ratio in the intraspecific amphigenetic progeny of Asia II7 ICWH and ICWL lines; interestingly, male-killing induction was enhanced with increased Cardinium titer. Moreover, single infection of Wolbachia induced partial CI in the Asia II7 IW line and resulted in reduced fecundity, higher embryonic mortality, and lower female sex ratio. The uninfected Asia II7 IU line had significantly higher fecundity, lower embryonic and nymphal mortalities, and a lower level of CI than both the Wolbachia-infected Asia II7 IW line and the Cardinium-Wolbachia-coinfected Asia II7 ICWH line. Our findings indicate that Cardinium-Wolbachia coinfection induced male-killing, which may have had antagonistic effects on Wolbachia-induced CI in the Asia II7 whiteflies. For the first time, our study revealed that B. tabaci Asia II7 reproduction is co-manipulated by Cardinium and Wolbachia endosymbionts.
Assuntos
Bacteroidetes/fisiologia , Hemípteros/microbiologia , Wolbachia/fisiologia , Animais , Feminino , Fertilidade , Hemípteros/fisiologia , Longevidade , Masculino , Razão de MasculinidadeRESUMO
Wang, Xing-Min, Hui Liu, Jian-Yu Li, Jin-Xia Wei, Xia Li, Yong-Liang Zhang, Ling-Zhi Li, and Xi-Zheng Zhang. Rosamultin attenuates acute hypobaric hypoxia-induced bone injuries by regulation of sclerostin and its downstream signals. High Alt Med Biol. 21:273-286, 2020. Background: Rosamultin, one of the compounds extracted from Potentilla anserina L., exhibited significant pharmacological activity against oxidative stress and hypoxic injury in our previous study. However, the effect of rosamultin on bone damage induced by acute hypobaric hypoxia (HH) has not been thoroughly studied. Methods: In this study, we first investigated the protective effect of rosamultin against bone damage in rats following acute exposure to simulated high-altitude hypoxia. Furthermore, we explored the detailed mechanism involved in the regulation of rat bone remodeling by rosamultin in an acute HH environment through analysis of sclerostin expression and the regulation of downstream signaling pathways. Results: Pretreatment with rosamultin significantly reduced HH-induced oxidative stress and inflammation, improved bone metabolic abnormalities, and alleviated the imbalance in bone remodeling in rats exposed to acute HH. Rosamultin markedly downregulated the expression of sclerostin, activated the Wnt/ß-catenin signaling pathway, and enhanced the ratio of osteoprotegerin/receptor activator of nuclear factor kappa B ligand to maintain the balance of bone formation and resorption. Conclusions: Rosamultin attenuates acute HH-induced bone damage and improves abnormal bone remodeling in rats by inhibition of sclerostin expression and activation of the Wnt/ß-catenin signaling pathway.
Assuntos
Triterpenos , Via de Sinalização Wnt , Animais , Hipóxia/complicações , Hipóxia/tratamento farmacológico , Estresse Oxidativo , RatosRESUMO
Biological control is an effective method for whitefly management compared to the potential problems caused by chemical control, including environmental pollution and the development of resistance. Combined use of insect parasitoids and entomopathogenic fungi has shown high efficiency in Bemisia tabaci control. Here, we assessed the impacts of an entomopathogenic fungus, Cordyceps javanica, on the parasitism rate of a dominant whitefly parasitoid, Eretmocerus hayati, and for the first time also compared their separate and combined potential in the suppression of B. tabaci under semi-field conditions. Six conidial concentrations of C. javanica (1 × 103, 1 × 104, 1 × 105, 1 × 106, 1 × 107 and 1 × 108 conidia/mL) were used to assess its pathogenicity to the pupae and adults of E. hayati. Results showed that the mortality of E. hayati increased with higher concentrations of C. javanica, but these higher concentrations of fungus had low pathogenicity to both the E. hayati pupae (2.00-28.00% mortality) and adults (2.67-34.00% mortality) relative to their pathogenicity to B. tabaci nymphs (33.33-92.68%). Bioassay results indicated that C. javanica was harmless (LC50 = 3.91 × 1010) and slightly harmful (LC50 = 5.56 × 109) to the pupae and adults of E. hayati respectively on the basis of IOBC criteria, and that E. hayati could parasitize all nymphal instars of B. tabaci that were pretreated with C. javanica, with its rate of parasitism being highest on second-instar nymphs (62.03%). Interestingly, the parasitoids from second and third-instar B. tabaci nymphs infected with C. javanica had progeny with increased longevity and developmental periods. Moreover, experimental data from 15 day semi-field studies indicate that combined application of C. javanica and E. hayati suppresses B. tabaci with higher efficiency than individual applications of both agents. Therefore, combined applications of C. javanica (1 × 108 conidia/mL) and E. hayati is a more effective and compatible biological control strategy for management of B. tabaci than using either of them individually.
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Maternal transmission is the main transmission pathway of facultative bacterial endosymbionts, but phylogenetically distant insect hosts harbor closely related endosymbionts, suggesting that horizontal transmission occurs in nature. Here we report the first case of plant-mediated horizontal transmission of Wolbachia between infected and uninfected Bemisia tabaci AsiaII7 whiteflies. After infected whiteflies fed on cotton leaves, Wolbachia was visualized, both in the phloem vessels and in some novel 'reservoir' spherules along the phloem by fluorescence in situ hybridization using Wolbachia-specific 16S rRNA probes and transmission electron microscopy. Wolbachia persisted in the plant leaves for at least 50 days. When the Wolbachia-free whiteflies fed on the infected plant leaves, the majority of them became infected with the symbiont and vertically transmitted it to their progeny. Multilocus sequence typing and sequencing of the wsp (Wolbachia surface protein) gene confirmed that the sequence type of Wolbachia in the donor whiteflies, cotton phloem and the recipient whiteflies are all identical (sequence type 388). These results were replicated using cowpea and cucumber plants, suggesting that horizontal transmission is also possible through other plant species. Our findings may help explain why Wolbachia bacteria are so abundant in arthropods, and suggest that in some species, Wolbachia may be maintained in populations by horizontal transmission.
Assuntos
Hemípteros/microbiologia , Wolbachia/fisiologia , Animais , Cucumis sativus/microbiologia , Interações Hospedeiro-Patógeno , Tipagem de Sequências Multilocus , Filogenia , RNA Ribossômico 16S/genética , Vigna/microbiologia , Wolbachia/genéticaRESUMO
Bemisia tabaci (Gennadius) Middle East-Asia Minor 1 (MEAM1) is a well known invasive insect species. Little information is available on immune system of B. tabaci to date. In this study, one of the Toll-like receptors (TLR; namely BtToll) was cloned in MEAM1 B. tabaci which contains an open reading frame of 3153bp, encoding putative 1050 amino acids. Phylogenetic analysis indicated that BtToll is highly identitical with other members of the TLR family. Transcripts of BtToll detected through qRT-PCR were expressed in all developmental stages of B. tabaci and the highest expression level was observed in the 3rd nymphal instar. BtToll was highly expressed in response to immune challenge. RNA interference was used to knockdown the BtToll expression in adults through the oral route which resulted in significant reduction of BtToll transcript. When the adults were challenged with a mycotoxin from entomogenous fungi - destruxin A (DA) and RNAi, the median lethal concentration (LC50) decreased by 70.67% compared to DA treatment only. Our results suggest that BtToll is an important component of the B. tabaci immune system. RNAi technology using dsToll combined with general control methods (using toxin only) can be used as a potential strategy in integrated B. tabaci management programs.
Assuntos
Infecções Bacterianas/imunologia , Depsipeptídeos/farmacologia , Hemípteros/imunologia , Imunidade Inata/genética , Micoses/imunologia , Receptores Toll-Like/genética , Sequência de Aminoácidos , Animais , Sequência de Bases , Linhagem Celular , Imunidade Inata/imunologia , Dose Letal Mediana , Estrutura Secundária de Proteína , Interferência de RNA , RNA Interferente Pequeno/genética , Receptores Toll-Like/metabolismoRESUMO
The sweetpotato whitefly Bemisia tabaci (Gennadius) was challenged with different combinations of matrine (insecticide) and Lecanicillium muscarium (entomopathogenic fungus). Our results revealed a synergistic relationship between matrine and L. muscarium on mortality and enzyme activities of B. tabaci. To illustrate the biochemical mechanisms involved in detoxification and immune responses of B. tabaci against both control agents, activities of different detoxifying and antioxidant enzymes were quantified. After combined application of matrine and L. muscarium, activities of carboxylestrease (CarE), glutathione-s-transferase (GSTs) and chitinase (CHI) decreased during the initial infection period. Acetylcholinestrase (AChE) activities increased during the entire experimental period, whereas those of superoxide dismutase (SOD), peroxidase (POD) and catalase (CAT) decreased during the later infection period. The increased mortality and suppression of enzymatic response of B. tabaci following matrine and L. muscarium application suggests a strong synergistic effect between both agents. The strong synergistic effect is possibly related to the disturbance of acetylcholine balance and changes in AchE activities of the whitefly as both matrine and L. muscarium target insect acetylcholine (Ach) receptors which in turn effects AchE production. Therefore, our results have revealed the complex biochemical processes involved in the synergistic action of matrine and L. muscarium against B. tabaci.
Assuntos
Alcaloides/toxicidade , Hemípteros/microbiologia , Hypocreales/fisiologia , Controle Biológico de Vetores/métodos , Quinolizinas/toxicidade , Animais , Catalase/metabolismo , Quitinases/metabolismo , Regulação para Baixo/efeitos dos fármacos , Glutationa Transferase/metabolismo , Hemípteros/enzimologia , Hemípteros/fisiologia , Proteínas de Insetos/metabolismo , Inseticidas/toxicidade , Ipomoea batatas/microbiologia , Ipomoea batatas/parasitologia , MatrinasRESUMO
A fluorescence method is presented for the determination of DNA. The method is based on the interaction of LaL3 [L = morin (2', 3, 4', 5, 7-Pentahydroxyflavone), 2'-OH group deprotonated] with DNA in NH3 x H2O-NH4Cl buffer of pH = 8.0, with lambdaex at 387 nm, and lambdaem at 535 nm. Enhanced fluorescence was observed for LaL3 in the presence of DNA and in the presence of buffer solution of 10%(psi) and ethanol of 10%(psi). The linear range of determination was between 0 and 15 microg x mL(-1) 1 for DNA. The method proved to be simple, easy and sensitive for the determination of DNA. The mechanism of enhancing and the reasons for the effects of acid were also discussed.
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DNA/análise , Espectrometria de Fluorescência/métodos , DNA/química , Fluorescência , Nanotecnologia/métodosRESUMO
The ladybird Propylaea japonica (Thunberg) is one of most important natural enemies of aphids in China. This species is threatened by the extensive use of insecticides but genomics-based information on the molecular mechanisms underlying insecticide resistance is limited. Hence, we analyzed the transcriptome and expression profile data of P. japonica in order to gain a deeper understanding of insecticide resistance in ladybirds. We performed de novo assembly of a transcriptome using Illumina's Solexa sequencing technology and short reads. A total of 27,243,552 reads were generated. These were assembled into 81,458 contigs and 33,647 unigenes (6,862 clusters and 26,785 singletons). Of the unigenes, 23,965 (71.22%) have putative homologues in the non-redundant (nr) protein database from NCBI, using BLASTX, with a cut-off E-value of 10(-5). We examined COG, GO and KEGG annotations to better understand the functions of these unigenes. Digital gene expression (DGE) libraries showed differences in gene expression profiles between two insecticide resistant strains. When compared with an insecticide susceptible profile, a total of 4,692 genes were significantly up- or down- regulated in a moderately resistant strain. Among these genes, 125 putative insecticide resistance genes were identified. To confirm the DGE results, 16 selected genes were validated using quantitative real time PCR (qRT-PCR). This study is the first to report genetic information on P. japonica and has greatly enriched the sequence data for ladybirds. The large number of gene sequences produced from the transcriptome and DGE sequencing will greatly improve our understanding of this important insect, at the molecular level, and could contribute to the in-depth research into insecticide resistance mechanisms.
Assuntos
Besouros/genética , Resistência a Inseticidas/genética , Animais , Besouros/efeitos dos fármacos , Besouros/metabolismo , Biologia Computacional , Perfilação da Expressão Gênica , Anotação de Sequência Molecular , Polimorfismo de Nucleotídeo Único , TranscriptomaRESUMO
The genus Shirozuella Sasaji, 1967 from the Chinese mainland is reviewed. Eight species are recognized, including four new species: Shirozuella motuoensissp. n., Shirozuella tibetinasp. n., Shirozuella unciformasp. n., and Shirozuella guoyueisp. n. Male genitalia of Shirozuella parenthesis Yu and Shirozuella quadrimacularis are described for the first time. All species are described and illustrated. A key and distribution map to the known species from the Chinese mainland are given.
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The genus Serangium Blackburn from China is reviewed. The genus Catanella Miyatake is removed from synonymy with Serangium. Serangium baculum Xiao is transferred to Catanella, as Catanella baculum (Xiao), comb. n. Twelve species of Serangium are described, keyed and illustrated, including eight new species, Serangium magnipunctatum Wang & Ren, sp. n., Serangium trimaculatum Wang & Ren, sp. n., Serangium centrale Wang & Ren, sp. n., Serangium leigongicus Wang & Ren, sp. n., Serangium latilobum Wang & Ren, sp. n., Serangium digitiforme Wang & Ren, sp. n., Serangium dulongjiang Wang, Ren & Chen, sp. n., and Serangium contortum Wang & Ren, sp. n.Serangium punctum Miyatake is newly recorded from China.
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The study on the development and reproduction of B-biotype Bemisia tabaci on four cucurbitaceous host plants, i. e., cucumber, hairy gourd, bitter cucumber, and sponge gourd, showed that the one generation development duration of B. tabaci was the shortest (19.3 d) on hairy gourd and the longest (29.0 d) on bitter cucumber, the survival rate from egg to adult was the highest (92.85%) on cucumber and the lowest (53.08%) on bitter cucumber, the laid eggs were the most (187.4 eggs per female) on cucumber and the least (30.0 eggs per female) on bitter cucumber, and the longevity was the longest (25.2 d) on cucumber and the shortest (10.9 d) on bitter cucumber. The intrinsic rate of increase (r(m)) on cucumber, hairy gourd, bitter cucumber, and sponge gourd was 0.1453, 0.1429, 0.0616, and 0.1055, respectively. Among the test cucurbitaceous host plants, cucumber was the most suitable host plant for B. tabaci.
Assuntos
Cucumis sativus/parasitologia , Cucurbitaceae/parasitologia , Hemípteros/crescimento & desenvolvimento , Animais , Cucurbitaceae/classificação , Hemípteros/fisiologia , Interações Hospedeiro-Parasita , Oviposição/fisiologia , Reprodução/fisiologia , Especificidade da EspécieRESUMO
In this paper, submersed plant Hydrilla verticillata was cultivated in a 1/10 Hoagland culture medium added with different concentration NH4 + -N (0, 0. 5, 2. 0, 4. 0 mg x L(-1)) and 10 mg x L(-1) cadmium to study the effects of NH4 + -N on H. verticillata growth and its antioxidant enzyme system under Cd stress, and approach the degradation mechanism of submersed macrophyte in eutrophic and polluted water bodies. The results showed that under 10 mg x L(-1) Cd stress, the chlorophyll content of H. verticillata decreased obviously, and SOD and POD activities increased first but declined then. NH4 + -N accelerated the stress effect of Cd. Under 0. 5 h joint stress of Cd and NH4 + -N, SOD activity increased significantly, while such an increase needed 3 hours under single Cd stress. Relative to chlorophyll and protein, antioxidant enzyme system was an early sensitive index, and SOD was more sensitive than POD. After two days exposure to Cd plus NH4 -N, H. verticillata was mainly stressed by Cd, and NH4+ -N stress could be neglected.
Assuntos
Cádmio/farmacologia , Hydrocharitaceae/crescimento & desenvolvimento , Nitrogênio/farmacologia , Superóxido Dismutase/metabolismo , Hydrocharitaceae/metabolismo , Estresse Oxidativo , Peroxidase/metabolismo , Compostos de Amônio Quaternário/farmacologiaRESUMO
Combined pollution is more ubiquitous than the single pollution in water and soil environment. Iodine method was used to study the effects of both single and combined pollution of Cd and NH4+ on Hydrilla verticillata and Myriophyllurn spicatum. Results came out that H. verticillata was distinctly stressed at 4.0 mg x L(-1) concentration of NHI4+, oxygen production of photosynthesis and oxygen depletion of respiration all declined, but for M. spicatum ,it was not be stressed. If treated with 0.2 mg x L(-1) Cd, H. verticillata and M. spicatum all were stressed, and H. verticillata was stressed more seriously. Combined pollution of Cd and NH4+ produced cooperative adverse effects on H. verticillata. But for M. spicatum, the stress was less severe comparatively. The main reason was that M. spicatum made of less crude cellulose. So it had less combined pathway with heavy mental than H. wvrticillata. It demonstrated that M. spicatum is suit for pioneer plant comparatively during the process of lake restoration.