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1.
Talanta ; 208: 120452, 2020 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-31816737

RESUMO

Plant cell walls represent enormous biomass resources for biofuels, and it thus becomes important to establish a sensitive and wide-applicable approach to visualize wall polymer distribution and destruction during plant growth and biomass process. Despite quantum dots (QDs) have been applied to label biological specimens, little is reported about its application in plant cell walls. Here, semiconductor QDs (CdSe/ZnS) were employed to label the secondary antibody directed to the epitopes of pectin or xylan, and sorted out the optimal conditions for visualizing two polysaccharides distribution in cell walls of rice stem. Meanwhile, the established QDs approach could simultaneously highlight wall polysaccharides and lignin co-localization in different cell types. Notably, this work demonstrated that the QDs labeling was sensitive to profile distinctive wall polymer destruction between alkali and acid pretreatments with stem tissues of rice. Hence, this study has provided a powerful tool to characterize wall polymer functions in plant growth and development in vivo, as well as their distinct roles during biomass process in vitro.

2.
Plant Cell Physiol ; 2019 Dec 23.
Artigo em Inglês | MEDLINE | ID: mdl-31868909

RESUMO

Iron (Fe) deficiency limits the yield of fruit trees. When subjected to Fe-deficiency, H+ secretion increases in the rhizosphere of dicotyledonous plants and pH decreases. This leads to the acidification of the soil and promotes Fe3+ to Fe2+ conversion, which plants can better uptake. This study investigated the relationship between two inhibitory transcription factors (ethylene response factors MbERF4 and MbERF72) and the H+-ATPase gene MbHA2. Two species of apple woody plants were studied: the Fe-inefficient Malus baccata and the Fe-efficient Malus xiaojinensis. Yeast one-hybrid and electrophoretic mobility shift assays showed that both MbERF4 and MbERF72 bind to the GCC cassette (AGCCGCC) of the MbHA2 promoter. Moreover, yeast two-hybrid and bimolecular fluorescence complementation assays showed that MbERF4 interacts with MbERF72. Furthermore, ß-glucuronidase and luciferase reporter assays showed that the MbERF4- and MbERF72-induced repression of MbHA2 expression is synergistic. Virus-induced gene silencing of MbERF4 or MbERF72 increased MbHA2 expression, and thus lowered the rhizosphere pH in M. baccata. Consequently, the high expressions of MbERF4 and MbERF72 induced by Fe-deficiency contributed to the Fe sensitivity of M. baccata. Moreover, the low expressions of MxERF4 and MxERF72 contributed to the Fe-deficiency tolerance of M. xiaojinensis via different binding conditions to the HA2 promoter. In summary, this study identified the relationship of two inhibitory transcription factors with the H+-ATPase gene and proposed a model in which ERF4 and ERF72 affect the rhizosphere pH in response to Fe-deficiency.

3.
Insects ; 10(12)2019 Nov 22.
Artigo em Inglês | MEDLINE | ID: mdl-31771090

RESUMO

The frequency and amplitude of heat waves are predicted to increase under future climate change conditions. We still lack a detailed understanding of how changes in the frequency and amplitude of heat waves are linked to the life history traits and biocontrol efficiency of host-feeding parasitoids. In the present study, we simulated a series of heat waves as a function of amplitude and frequency to investigate the effects on the life history traits of the host-feeding parasitoid Eretmocerus hayati. We found that both the amplitude and frequency of heat waves significantly affected the adult phenotypes. In the low-amplitude heat wave group, the frequency of heat waves did not change the life history traits of the parasitoid; however, when the heat amplitude reached 42 °C, medium (four times/week) and high frequencies (seven times/week) of heat waves detrimentally affected these parameters. Hence, these findings suggest that to obtain optimal biological control with this parasitoid, we need to carefully monitor heat wave pattern (especially the amplitude and frequency) over the short term (usually 7-10 days) before releasing a host-feeding parasitoid.

4.
Int J Mol Sci ; 20(22)2019 Nov 17.
Artigo em Inglês | MEDLINE | ID: mdl-31744249

RESUMO

ATP-binding cassette (ABC) transporters constitute a large, diverse, and ubiquitous superfamily that is involved in a broad range of processes. The completion of genome sequencing provides an opportunity to understand the phylogenetic history of the ABC transporter superfamily among Rosaceae species. This study identified a total of 1323 ABC transporter genes from nine Rosaceae genomes: 191 from Malus domestica, 174 from Pyrus communis, 138 from Prunus persica, 118 from Prunus avium, 141 from Prunus dulcis, 122 from Fragaria vesca, 98 from Rubus occidentalis, 162 from Prunus mume, and 179 from Rosa chinensis. Their chemical characterization, phylogenetic analysis, chromosomal localization, gene structure, gene duplication, and tissue-specific expression were studied. Their subcellular localization, transmembrane structures, and protein motifs were predicted. All the ABC transporter genes were grouped into eight subfamilies on the basis of their phylogenetic relationships and structural features. Furthermore, cis-element and expression analysis of 10 potential phytohormone transporters in MdABCG subfamily genes were also performed. Loss of the W-box in the promoter region of MdABCG28 was found to reduce the gene expression level and was linked to the dwarfing phenotype in apple rootstocks. MdABCG28 overexpression promoted shoot growth of atabcg14 mutants in Arabidopsis.

5.
Nat Commun ; 10(1): 4237, 2019 09 17.
Artigo em Inglês | MEDLINE | ID: mdl-31530873

RESUMO

The codling moth Cydia pomonella, a major invasive pest of pome fruit, has spread around the globe in the last half century. We generated a chromosome-level scaffold assembly including the Z chromosome and a portion of the W chromosome. This assembly reveals the duplication of an olfactory receptor gene (OR3), which we demonstrate enhances the ability of C. pomonella to exploit kairomones and pheromones in locating both host plants and mates. Genome-wide association studies contrasting insecticide-resistant and susceptible strains identify hundreds of single nucleotide polymorphisms (SNPs) potentially associated with insecticide resistance, including three SNPs found in the promoter of CYP6B2. RNAi knockdown of CYP6B2 increases C. pomonella sensitivity to two insecticides, deltamethrin and azinphos methyl. The high-quality genome assembly of C. pomonella informs the genetic basis of its invasiveness, suggesting the codling moth has distinctive capabilities and adaptive potential that may explain its worldwide expansion.


Assuntos
Cromossomos de Insetos/genética , Resistência a Inseticidas , Inseticidas/farmacologia , Mariposas/efeitos dos fármacos , Mariposas/genética , Animais , Duplicação Gênica , Genoma de Inseto , Proteínas de Insetos/genética , Proteínas de Insetos/metabolismo , Mariposas/metabolismo , Feromônios/metabolismo , Polimorfismo de Nucleotídeo Único , Regiões Promotoras Genéticas , Receptores Odorantes/genética , Receptores Odorantes/metabolismo
6.
Insects ; 10(5)2019 May 14.
Artigo em Inglês | MEDLINE | ID: mdl-31091677

RESUMO

Bactrocera minax, one of the most devastating citrus pests in Asia, has two developmental stages (mature larva and pupa) that complete their life cycle in the soil. Currently, southern China has a climate with abundant autumn rains, and soil moisture can be a major factor affecting the survival of larvae and pupae of B. minax. In the present study, we evaluated the effects of water immersion and high soil moisture content on the development of mature larvae and pupae of B. minax. When immersed in water for 1 d, 100% of mature larvae of B. minax were knocked out. When larvae were immersed for less than 6 d, however, more than 92% of knocked-out larvae recovered within 24 h. The days of water immersion with 50% and 90% recovery ratios (indicated as RD50 and RD90) were 10.3 d and 6.4 d, respectively. When larvae were immersed less than 6 d, the mortality ratios of larvae were not significantly different from those that were not immersed at all. The days of immersion causing 50% and 90% mortality of larvae (MD50 and MD90, respectively) were 7.6 d and 11.1 d, respectively. The pupation ratios of larvae were also observed to be not significantly different compared to non-immersion, and the days of immersion causing 50% and 90% pupation (PD50 and PD90, respectively) were 6.6 d and 0.8 d, respectively. Larval respiration rates were reduced after water immersion as a strategy for larval survival. High water content was not detrimental to pupae of B. minax. Adult emergence did not significantly decrease in soil with high water content, even though pupae were under those conditions for 161-175 d. The respiration rates of pupae were lower in soil with different moisture levels and were not significantly different, which ensured the survival of pupae in high water content. Reduced respiration rate is a strategy for survival of larvae and pupae, and remarkable tolerance to high moisture conditions could explain the high rate of spread and geographical distribution of B. minax. The results of this study provide a reference for the occurrence and control of B. minax.

7.
Sci Rep ; 9(1): 2202, 2019 Feb 18.
Artigo em Inglês | MEDLINE | ID: mdl-30778089

RESUMO

Parasitoids are insects (usually wasps or flies) that lay eggs within or on other insects (their hosts). Host-feeding parasitoids lay eggs to parasitize the host and feed directly on the host for nourishment. Temperature is the most critical factor affecting insect behavioral responses. Few studies have focused on the impacts of variable temperatures across different life stages on the behaviors of host-feeding parasitoids. This study investigated the effects of temperature experienced during the preadult and adult stages on the life history traits and life table parameters of females of a host-feeding parasitoid, Eretmocerus hayati. Our results show that the temperatures experienced during the preadult and adult stages significantly change life history traits (immature development, adult longevity, host feeding and fecundity). Increasing the preadult temperature resulted in shorter development times for immature stages of the parasitoid, and decreasing the temperature during the adult stage increased reproduction and longevity. Most importantly, we found that host-feeding events changed with temperature rather than life stage. The daily host-feeding ability of the parasitoid increased with increasing temperature at all temperatures except the stress temperature (34 °C). Furthermore, switching temperatures at the immature stage and adult stage can increase the values of life table parameters, with the highest intrinsic rate of increase (r) occurring in the 30/26 °C treatment. This study provides new insight into the mass rearing of parasitic natural enemies.

8.
Plant Cell Environ ; 42(2): 424-436, 2019 02.
Artigo em Inglês | MEDLINE | ID: mdl-29989184

RESUMO

Plants experiencing salt-induced stress often reduce cytokinin levels during the early phases of stress-response. Interestingly, we found that the cytokinin content in the apple rootstock "robusta" was maintained at a high level under salt stress. Through screening genes involved in cytokinin biosynthesis and catabolism, we found that the high expression levels of IPT5b in robusta roots were involved in maintaining the high cytokinin content. We identified a 42 bp deletion in the promoter region of IPT5b, which elevated IPT5b expression levels, and this deletion was linked to salt tolerance in robusta×M.9 segregating population. The 42 bp deletion resulted in the deletion of a Proline Response Element (ProRE), and our results suggest that ProRE negatively regulates IPT5b expression in response to proline. Under salt stress, the robusta cultivar maintains high cytokinin levels as IPT5b expression cannot be inhibited by proline due to the deletion of ProRE, leading to improve salt tolerance.

9.
PLoS One ; 14(12): e0226818, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31891602

RESUMO

For molecular research, the quality and integrity of DNA obtained will affect the reliability of subsequent results. Extracting quality DNA from scale insects, including mealybugs, can be difficult due to their small body size and waxy coating. In this study, we evaluate eight commonly used DNA extraction methods to determine their efficacy in PCR analysis across life stages and preservation times. We find that fresh samples, immediately upon collection or after 2 wks, resulted in the most effective DNA extraction. Methods using the DNeasy Blood & Tissue kit, NaCl, SDS-RNase A, and SDS isolated DNA of sufficient quality DNA. The SDS method gave high DNA yield, while the NaCl and SDS-RNase A methods gave lower yield. NaCl, SDS-RNase A, SDS, chloroform-isopentyl alcohol, and the salting-out methods all resulted in sufficient DNA for PCR, and performed equal to or better than that of the DNeasy Blood & Tissue kit. When time and cost per extraction were considered, the SDS method was most efficient, especially for later life stages of mealybug, regardless of preservation duration. DNA extracted from a single fresh sample of a female adult mealybug was adequate for more than 10,000 PCR reactions. For earlier stages, including the egg and 1st instar nymph samples, DNA was most effectively extracted by the Rapid method. Our results provide guidelines for the choice of effective DNA extraction method for mealybug or other small insects across different life stages and preservation status.

10.
FEBS Lett ; 592(20): 3446-3459, 2018 10.
Artigo em Inglês | MEDLINE | ID: mdl-30238451

RESUMO

Understanding the mechanism of iron (Fe)-deficiency responses is crucial for improving plant Fe bioavailability. Here, we found that the Arabidopsis Rho-like GTPase 6 mutant (rop6) is less sensitive to Fe-deficiency responses and has reduced levels of reactive oxygen species (ROS) compared to wild-type (WT), while AtROP6-overexpressing seedlings exhibit more sensitivity to Fe-deficiency responses and has higher levels of ROS compared to WT. Moreover, treatment with H2 O2 improves the sensitivity to Fe-deficiency responses in rop6 mutants. By using the yeast two-hybrid system, we further demonstrate the direct interaction between AtROP6 and Arabidopsis respiratory burst oxidase homolog D (AtRBOHD), which controls the generation of ROS. Overall, we suggest that AtROP6 is involved in AtRBOHD-mediated ROS signaling to modulate Fe-deficiency responses in Arabidopsis thaliana.


Assuntos
Proteínas de Arabidopsis/metabolismo , Arabidopsis/metabolismo , Ferro/metabolismo , Proteínas Monoméricas de Ligação ao GTP/metabolismo , Espécies Reativas de Oxigênio/metabolismo , Transdução de Sinais , Arabidopsis/genética , Proteínas de Arabidopsis/genética , Regulação da Expressão Gênica de Plantas , Peróxido de Hidrogênio/farmacologia , Proteínas Monoméricas de Ligação ao GTP/genética , Mutação , NADPH Oxidases/genética , NADPH Oxidases/metabolismo , Oxidantes/farmacologia , Plantas Geneticamente Modificadas , Ligação Proteica , Plântula/genética , Plântula/metabolismo , Estresse Fisiológico/efeitos dos fármacos
11.
J Econ Entomol ; 111(5): 2120-2128, 2018 09 26.
Artigo em Inglês | MEDLINE | ID: mdl-30060026

RESUMO

The Jack Beardsley mealybug, Pseudococcus jackbeardsleyi Gimpel & Miller (Hemiptera: Pseudococcidae), a globally devastating, invasive polyphagous insect, causes great damage to many fruits, ornamentals, vegetables, and food crops worldwide. It is of Neotropical origin and has invaded throughout America and in parts of Asia, Africa and Oceania, and is still expanding its invasion ranges. Therefore, a method for quick and correct identification of this invasive species is crucial for quarantine and spreading interruption of it. In present study, we report the first record of P. jackbeardsleyi on the Chinese mainland, which would cause great damage to many crops. The identification of P. jackbeardsleyi was verified via morphological characters and DNA barcoding. One pair of species-specific polymerase chain reaction (SS-PCR) primers was designed based on variations in the sequences of the mitochondrial cytochromecoxidasesubunitI gene among P. jackbeardsleyi and 28 other mealybug species. No cross-reaction was detected among 21 closely related species using this SS-PCR assay, demonstrating the specificity of this marker. Furthermore, this method was successfully applied to detect individuals from different developmental stages and adult debris across four geographic populations of P. jackbeardsleyi, showing the high stability of the assay. Additionally, the detection limit of the marker was 55.94 ± 5.05 pg/µl of P. jackbeardsleyi DNA, illustrating the high sensitivity of the assay. The SS-PCR assay developed in this study provides a rapid, simple and reliable method for the identification of P. jackbeardsleyi, which should be crucial in the plant quarantine, early detection and sustainable management of this globally invasive pest.


Assuntos
Hemípteros/classificação , Espécies Introduzidas , Animais , China , Código de Barras de DNA Taxonômico , Feminino , Hemípteros/anatomia & histologia , Hemípteros/genética , Reação em Cadeia da Polimerase
12.
Sci Rep ; 8(1): 3636, 2018 02 26.
Artigo em Inglês | MEDLINE | ID: mdl-29483532

RESUMO

Lignin content and composition are crucial factors affecting biomass digestibility. Exploring the genetic loci simultaneously affecting lignin-relevant traits and biomass digestibility is a precondition for lignin genetic manipulation towards energy crop breeding. In this study, a high-throughput platform was employed to assay the lignin content, lignin composition and biomass enzymatic digestibility of a rice recombinant inbred line population. Correlation analysis indicated that the absolute content of lignin monomers rather than lignin content had negative effects on biomass saccharification, whereas the relative content of p-hydroxyphenyl unit and the molar ratio of p-hydroxyphenyl unit to guaiacyl unit exhibited positive roles. Eight QTL clusters were identified and four of them affecting both lignin composition and biomass digestibility. The additive effects of clustered QTL revealed consistent relationships between lignin-relevant traits and biomass digestibility. Pyramiding rice lines containing the above four positive alleles for increasing biomass digestibility were selected and showed comparable lignin content, decreased syringyl or guaiacyl unit and increased molar percentage of p-hydroxyphenyl unit, the molar ratio of p-hydroxyphenyl unit to guaiacyl unit and sugar releases. More importantly, the lodging resistance and eating/cooking quality of pyramiding lines were not sacrificed, indicating the QTL information could be applied to select desirable energy rice lines.


Assuntos
Lignina/metabolismo , Oryza/genética , Oryza/metabolismo , Biomassa , Loci Gênicos/genética , Locos de Características Quantitativas/genética
13.
PLoS One ; 10(6): e0128892, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-26057559

RESUMO

The transformer (tra) gene appears to act as the genetic switch that promotes female development by interaction with the transformer2 (tra-2) gene in several dipteran species including the Medfly, housefly and Drosophila melanogaster. In this study, we describe the isolation, expression and function of tra and tra-2 in the economically important agricultural pest, the oriental fruit fly, Bactrocera dorsalis (Hendel). Bdtra and Bdtra-2 are similar to their homologs from other tephritid species. Bdtra demonstrated sex-specific transcripts: one transcript in females and two transcripts in males. In contrast, Bdtra-2 only had one transcript that was common to males and females, which was transcribed continuously in different adult tissues and developmental stages. Bdtra-2 and the female form of Bdtra were maternally inherited in eggs, whereas the male form of Bdtra was not detectable until embryos of 1 and 2 h after egg laying. Function analyses of Bdtra and Bdtra-2 indicated that both were indispensable for female development, as nearly 100% males were obtained with embryonic RNAi against either Bdtra or Bdtra-2. The fertility of these RNAi-generated males was subsequently tested. More than 80% of RNAi-generated males could mate and the mated females could lay eggs, but only 40-48.6% males gave rise to progeny. In XX-reversed males and intersex individuals, no clear female gonadal morphology was observed after dissection. These results shed light on the development of a genetic sexing system with male-only release for this agricultural pest.


Assuntos
Dípteros/genética , Inativação Gênica , Proteínas de Insetos/metabolismo , Proteínas de Ligação a RNA/metabolismo , Processos de Determinação Sexual/genética , Diferenciação Sexual/genética , Animais , Dípteros/fisiologia , Feminino , Proteínas de Insetos/genética , Masculino , Proteínas de Ligação a RNA/genética
14.
Bioorg Med Chem Lett ; 25(14): 2809-12, 2015 Jul 15.
Artigo em Inglês | MEDLINE | ID: mdl-25987372
15.
Acta Crystallogr F Struct Biol Commun ; 70(Pt 2): 173-81, 2014 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-24637750

RESUMO

Tau-tubulin kinase 1 (TTBK1) is a dual-specificity (serine/threonine and tyrosine) kinase belonging to the casein kinase 1 superfamily. TTBK1 is a neuron-specific kinase that regulates tau phosphorylation. Hyperphosphorylation of tau is implicated in the pathogenesis of Alzheimer's disease. Two kinase-domain constructs of TTBK1 were expressed in a baculovirus-infected insect-cell system and purified. The purified TTBK1 kinase-domain proteins were crystallized using the hanging-drop vapor-diffusion method. X-ray diffraction data were collected and the structure of TTBK1 was determined by molecular replacement both as an apo structure and in complex with a kinase inhibitor.


Assuntos
Inibidores de Proteínas Quinases/química , Proteínas Serina-Treonina Quinases/química , Animais , Baculoviridae/genética , Cristalização , Cristalografia por Raios X , Eletroforese em Gel de Poliacrilamida , Humanos , Espectroscopia de Ressonância Magnética , Conformação Proteica , Células Sf9 , Especificidade por Substrato
16.
Pest Manag Sci ; 70(12): 1797-807, 2014 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-24343857

RESUMO

BACKGROUND: The two common whitefly species, Bemisia tabaci (Gennadius) MEAM1 and Trialeurodes vaporariorum (Westwood), often co-occur on their host plants. The effect of host plant occupation by one species on later-arriving conspecific individuals or on the other competing species was examined. RESULTS: Resource preoccupied by T. vaporariorum had mostly negative effects on the life history parameters of later-arriving conspecifics. Red-eyed nymph and immature survival of T. vaporariorum decreased when resource was preoccupied by conspecifics, irrespective of the previous occupation scenario. However, resource preoccupied by T. vaporariorum had only minor detrimental effects on the performance of later-arriving B. tabaci MEAM1. In the opposite colonisation sequence, previous occupation by B. tabaci MEAM1 had no significant effects on the life history parameters of later-arriving conspecifics, but severe detrimental effects were observed on the performance of later-arriving T. vaporariorum. Total immature survival of T. vaporariorum decreased in both weak and strong previous occupation situations by B. tabaci MEAM1. CONCLUSION: The interspecific interactions between B. tabaci MEAM1 and T. vaporariorum were asymmetric, with B. tabaci MEAM1 being the superior competitor. This superiority could partially explain the rapid spread of B. tabaci MEAM1 in China.


Assuntos
Comportamento Competitivo , Hemípteros/fisiologia , Animais , China , Feminino , Fertilidade , Hemípteros/crescimento & desenvolvimento , Estágios do Ciclo de Vida , Longevidade , Lycopersicon esculentum/parasitologia , Masculino , Ninfa/crescimento & desenvolvimento , Ninfa/fisiologia , Dinâmica Populacional , Especificidade da Espécie
17.
Environ Entomol ; 41(5): 1125-30, 2012 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-23068168

RESUMO

The suitability of tomato leaves of different ages for Bemisia tabaci (Gennadius) B biotype and Trialeurodes vaporariorum (Westwood) was characterized by development time, stage-specific survival, sex ratio, longevity, and fecundity. Three categories of leaf ages were tested (young: expanding leaves <2 wk old; mature: fully expanded, 4-5-wk-old leaves; old: fully expanded, 6-7-wk-old leaves). There was no significant variation in the duration of development of the two species among the three classes of leaf ages, but total survival and ratio of females to males on mature and old leaves were higher than on young leaves. For egg hatch, the reverse tendency was found. Longevity of both species was higher on mature than on young leaves, and fecundity during the first 2 wk of adult life was higher on mature than on young or old leaves. The B. tabaci B biotype developed faster through the quiescent fourth nymphal instar, had higher ratio of females to males, survived longer, and produced more eggs (in the first 2 wk of adult life) than T. vaporariorum on leaves of the same age; although on young leaves, B. tabaci B biotype survivorship was lower than that of T. vaporariorum. The index of host suitability of B. tabaci B biotype was higher on mature and old leaves than on young leaves. In T. vaporariorum, no such differences were found among these three leaf ages. The results could provide some cues why B. tabaci B biotype is spreading so vigorously.


Assuntos
Hemípteros/crescimento & desenvolvimento , Especificidade de Hospedeiro , Lycopersicon esculentum/parasitologia , Folhas de Planta/parasitologia , Animais , Feminino , Fertilidade , Longevidade , Masculino , Folhas de Planta/fisiologia , Razão de Masculinidade
18.
Org Biomol Chem ; 10(16): 3185-8, 2012 Apr 28.
Artigo em Inglês | MEDLINE | ID: mdl-22407032

RESUMO

A calix[4]arene acetylene (C4AE)-modified gold surface is successfully constructed in situ via click chemistry. The functionalized surface is used for selective recognition of paraquat by a wettability switch. Impedance measurements showed that the surface also expresses recognition for paraquat with a high sensitivity of 10 pM. The recognition mode, based on host-guest inclusion, is studied by computational calculations and the possible mechanism is analyzed.


Assuntos
Calixarenos/química , Técnicas Eletroquímicas/métodos , Herbicidas/análise , Paraquat/análise , Fenóis/química , Acetileno/síntese química , Acetileno/química , Calixarenos/síntese química , Química Click , Impedância Elétrica , Ouro/química , Fenóis/síntese química , Sensibilidade e Especificidade , Propriedades de Superfície , Molhabilidade
19.
Environ Entomol ; 40(1): 140-50, 2011 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-22182623

RESUMO

Bemisia tabaci (Gennadius) biotype B and Trialeurodes vaporariorum (Westwood) are invasive whitefly species that often co-occur on greenhouse-grown vegetables in northern China. Although B. tabaci biotype B has been present in China for a relatively short period of time, it has become dominant over T. vaporariorum. We studied the interspecific competitive interactions between the two species in single or mixed cultures at 24 ± 1 °C, 40 ± 5% RH, and L14:D10 h photoperiod. Female longevity on tomato was not significantly different between species, but B. tabaci reproduced 4.3 to 4.9 fold more progeny. The ratio of female to male progeny in both instances was greater for B. tabaci. When cultured on tomato, cotton, and tobacco, B. tabaci developed 0.8, 3.3, and 4.7 d earlier in single culture, and 1.8, 3.9, and 4.3 d earlier in mixed culture. B. tabaci displaced T. vaporariorum in four, five and six generations when the initial ratios of B. tabaci to T. vaporariorum were 15:15, 20:10, or 10:20 on tomato. Populations of B. tabaci were 2.3 fold higher than that of T. vaporariorum on tomato plants for seven consecutive generations in single culture. B. tabaci performed better in development, survival, fecundity, and female ratio. We conclude that B. tabaci could displace T. vaporariorum in as short as four generations in a controlled greenhouse environment when they start at equal proportions. Warmer greenhouse conditions and an increase in total greenhouse area could be contributing factors in the recent dominance of B. tabaci.


Assuntos
Hemípteros/crescimento & desenvolvimento , Animais , China , Comportamento Competitivo , Feminino , Gossypium , Hemípteros/fisiologia , Lycopersicon esculentum , Masculino , Ninfa/crescimento & desenvolvimento , Ninfa/fisiologia , Óvulo/crescimento & desenvolvimento , Óvulo/fisiologia , Dinâmica Populacional , Especificidade da Espécie , Tabaco
20.
Org Lett ; 13(13): 3392-5, 2011 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-21630700

RESUMO

A calix[4]arene lipoic acid (C4LA) was synthesized by click chemistry in 62% yield. It was immobilized on Au surfaces via self-assembly to offer C4LA Self-Assembled Monolayers (SAMs). The SAMs show wettability and electrochemical impedance dual-signal response for methomyl with highly sensitivity and selectivity.


Assuntos
Calixarenos/química , Carbamatos/química , Praguicidas/química , Ácido Tióctico/análogos & derivados , Ácido Tióctico/química , Molhabilidade , Impedância Elétrica , Ouro/química , Estrutura Molecular , Propriedades de Superfície
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