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1.
J Agric Food Chem ; 71(18): 7152-7162, 2023 May 10.
Article in English | MEDLINE | ID: mdl-37104842

ABSTRACT

As chemical pesticides have caused serious environmental pollution, fungus-based biological control has become a developing alternative to chemical control. Here, we aimed to determine the molecular mechanism underlying how Metarhizium anisopliae facilitated invasive infection. We found that the fungus increased its virulence by downregulating glutathione S-transferase (GST) and superoxide dismutase (SOD) throughout termite bodies. Among 13 fungus-induced microRNAs throughout termite bodies, miR-7885-5p and miR-252b upregulation significantly downregulated several mRNAs in response to toxic substances to increase the fungal virulence [e.g., phosphoenolpyruvate carboxykinase (GTP) and heat shock protein homologue SSE1]. In addition, nanodelivered small interfering RNA of GST and SOD and miR-7885-5p and miR-252b mimics increased the virulence of the fungus. These findings provide new insights into the killing mechanism of entomopathogens and their utilization of the host miRNA machinery to reduce host defenses, laying the groundwork to enhance virulence of biocontrol agents for green pest management.


Subject(s)
Isoptera , Metarhizium , MicroRNAs , Animals , Isoptera/genetics , Transcriptome , Pest Control, Biological , Metarhizium/genetics , MicroRNAs/genetics
2.
Environ Microbiol ; 23(9): 5164-5183, 2021 09.
Article in English | MEDLINE | ID: mdl-33817929

ABSTRACT

Chromatin transitions are mediated in part by acetylation/deacetylation post-translational modifications of histones. Histone deacetylases, e.g. sirtuins (Sir-proteins), repress transcription via promotion of heterochromatin formation. Here, we characterize the Sir2 class III histone deacetylase (BbSir2) in the environmentally and economically important fungal insect pathogen, Beauveria bassiana. BbSir2 is shown to contribute to the deacetylation of lysine residues on H3 and H4 histones. Targeted gene knockout of BbSir2 resulted in impaired asexual development, reduced abilities to utilize various carbon/nitrogen sources, reduced tolerance to oxidative, heat, and UV stress, and attenuated virulence. ΔBbSir2 cells showed disrupted cell cycle development and abnormal hyphal septation patterns. Proteomic protein acetylation analyses of wild type and ΔBbSir2 cells revealed the differential abundance of 462 proteins and altered (hyper- or hypo-) acetylation of 436 lysine residues on 350 proteins. Bioinformatic analyses revealed enrichment in pathways involved in carbon/nitrogen metabolism, cell cycle control and cell rescue, defence and mitochondrial functioning. Critical targets involved in virulence included LysM effector proteins and a benzoquinone oxidoreductase implicated in detoxification of cuticular compounds. These data indicate broad effects of BbSir2 on fungal development and stress response, with identification of discrete targets that can account for the observed (decreased) virulence phenotype.


Subject(s)
Beauveria , Fungal Proteins , Sirtuins , Animals , Beauveria/genetics , Fungal Proteins/genetics , Insecta , Proteomics , Sirtuins/genetics , Spores, Fungal , Virulence
3.
Insect Sci ; 28(1): 77-92, 2021 Feb.
Article in English | MEDLINE | ID: mdl-32039551

ABSTRACT

Swarming behavior facilitates pair formation, and therefore mating, in many eusocial termites. However, the physiological adjustments and morphological transformations of the flight muscles involved in flying and flightless insect forms are still unclear. Here, we found that the dispersal flight of the eusocial termite Reticulitermes chinensis Snyder led to a gradual decrease in adenosine triphosphate supply from oxidative phosphorylation, as well as a reduction in the activities of critical mitochondrial respiratory enzymes from preflight to dealation. Correspondingly, using three-dimensional reconstruction and transmission electron microscopy (TEM), the flight muscles were found to be gradually deteriorated during this process. In particular, two tergo-pleural muscles (IItpm5 and III-tpm5) necessary to adjust the rotation of wings for wing shedding behavior were present only in flying alates. These findings suggest that flight muscle systems vary in function and morphology to facilitate the swarming flight procedure, which sheds light on the important role of swarming in successful extension and fecundity of eusocial termites.


Subject(s)
Flight, Animal , Isoptera , Animals , Female , Isoptera/anatomy & histology , Isoptera/chemistry , Isoptera/physiology , Isoptera/ultrastructure , Male , Microscopy, Electron, Transmission , Muscles/anatomy & histology , Muscles/chemistry , Muscles/physiology , Muscles/ultrastructure , Reproduction
4.
Pest Manag Sci ; 75(12): 3135-3143, 2019 Dec.
Article in English | MEDLINE | ID: mdl-31251458

ABSTRACT

Many insects, especially nocturnal insects, exhibit positive phototaxis to artificial lights. Light traps are currently used to monitor and manage insect pest populations, and play a crucial role in physical pest control. Efficient use of light traps to attract target insect pests is an important topic in the application of integrated pest management (IPM). Phototactic responses of insects vary among species, light characteristics and the physiological status of the insects. In addition, light can cause several biological responses, including biochemical, physiological, molecular and fitness changes in insects. In this review, we discuss several hypotheses on insect phototaxis, factors affecting insect phototaxis, insect-sensitive wavelengths, biological responses of insects to light, and countermeasures for conserving beneficial insects and increasing the effect of trapping. In addition, we provide information on the different sensitivities to wavelengths causing positive phototactic behavior in > 70 insect pest and beneficial insect species. The use of advanced light traps equipped with superior light sources, such as light-emitting diodes (LEDs), will make physical pest control in IPM more efficient. © 2019 Society of Chemical Industry.


Subject(s)
Insect Control/methods , Insecta/physiology , Phototaxis , Animals
5.
Toxins (Basel) ; 11(5)2019 04 29.
Article in English | MEDLINE | ID: mdl-31035652

ABSTRACT

Entomopathogenic fungus as well as their toxins is a natural threat surrounding social insect colonies. To defend against them, social insects have evolved a series of unique disease defenses at the colony level, which consists of behavioral and physiological adaptations. These colony-level defenses can reduce the infection and poisoning risk and improve the survival of societal members, and is known as social immunity. In this review, we discuss how social immunity enables the insect colony to avoid, resist and tolerate fungal pathogens. To understand the molecular basis of social immunity, we highlight several genetic elements and biochemical factors that drive the colony-level defense, which needs further verification. We discuss the chemosensory genes in regulating social behaviors, the antifungal secretions such as some insect venoms in external defense and the immune priming in internal defense. To conclude, we show the possible driving force of the fungal toxins for the evolution of social immunity. Throughout the review, we propose several questions involved in social immunity extended from some phenomena that have been reported. We hope our review about social 'host-fungal pathogen' interactions will help us further understand the mechanism of social immunity in eusocial insects.


Subject(s)
Insecta/immunology , Insecta/microbiology , Social Behavior , Animals , Behavior, Animal , Host-Pathogen Interactions , Insecta/physiology , Mycotoxins
6.
Environ Sci Pollut Res Int ; 25(35): 35176-35183, 2018 Dec.
Article in English | MEDLINE | ID: mdl-30328544

ABSTRACT

Recently, light traps equipped with light-emitting diodes (LEDs) have been widely applied for controlling nocturnal pest moths. The oriental armyworm, known as Mythimna separata Walker, is an important insect pest in eastern Asia. The present study aimed to evaluate an influence of green light irradiation on antioxidant enzymes and light stress in M. separata adults. We determined total antioxidant capacity (T-AOC) and an activity of superoxide dismutase (SOD), catalase (CAT), peroxidase (POD), and glutathione-S-transferase (GST) in the moth bodies according to an exposure time (0 to 180 min) of a green LED light. By our results, we suggested that the green (520 nm) LED light irradiation could induce a weak oxidative stress in M. separata adult moths, and the moths under the green light could restore the damage caused by this light stress. Additionally, we proposed that the adaptive ability to the light stress varied between the moths of different sexes. Our results may provide a theoretical and scientific basis for elucidating a reason of the phototactic behavior of nocturnal moths, including M. separata adults.


Subject(s)
Antioxidants/metabolism , Moths/physiology , Oxidative Stress/physiology , Animals , Catalase/metabolism , Asia, Eastern , Glutathione Transferase/metabolism , Moths/enzymology , Peroxidases , Superoxide Dismutase/metabolism , Tumor Necrosis Factor Ligand Superfamily Member 14
7.
Acta Crystallogr C Struct Chem ; 73(Pt 8): 645-651, 2017 Aug 01.
Article in English | MEDLINE | ID: mdl-28776517

ABSTRACT

Careful choice of the organic ligands is one of the most important parameters in the rational design and synthesis of coordination polymers. Aromatic polycarboxylates have been widely used in the preparation of metal-organic polymers since they can utilize various coordination modes to form diverse structures and can act as hydrogen-bond acceptors and donors in the assembly of supramolecular structures. Nitrogen-heterocyclic organic compounds have also been used extensively as ligands for the construction of polymers with interesting structures. In the polymers catena-poly[[[diaquabis{2-[(1H-imidazol-1-yl)methyl]-6-methyl-1H-benzimidazole-κN3}cobalt(II)]-µ2-benzene-1,4-dicarboxylato-κ2O1:O4] dihydrate], {[Co(C8H4O4)(C12H11N4)2(H2O)2]·2H2O}n, (I), and catena-poly[[[diaquabis{2-[(1H-imidazol-1-yl)methyl]-6-methyl-1H-benzimidazole-κN3}nickel(II)]-µ2-benzene-1,4-dicarboxylato-κ2O1:O4] dihydrate], {[Ni(C8H4O4)(C12H11N4)2(H2O)2]·2H2O}n, (II), the CoII or NiII ion lies on an inversion centre and exhibits a slightly distorted octahedral coordination geometry, coordinated by two N atoms from two imidazole rings and four O atoms from two monodentate carboxylate groups and two water molecules. The dicarboxylate ligands bridge metal ions forming a polymeric chain. The 2-[(1H-imidazol-1-yl)methyl]-6-methyl-1H-benzimidazole ligands coordinate to the CoII or NiII centres in monodentate modes through an imidazole N atom and are pendant on opposite sides of the main chain. The two structures are isomorphous. In the crystal, the one-dimensional chains are further connected through O-H...O, O-H...N and N-H...O hydrogen bonds, leading to a three-dimensional supramolecular architecture. In addition, the IR spectroscopic properties, PXRD patterns, thermogravimetric behaviours and fluorescence properties of both polymers have been investigated.

8.
Acta Crystallogr C Struct Chem ; 73(Pt 4): 314-318, 2017 Apr 01.
Article in English | MEDLINE | ID: mdl-28378714

ABSTRACT

The unsymmetrical N-heterocyclic ligand 1-[(benzotriazol-1-yl)methyl]-1H-1,3-imidazole (bmi) has three potential N-atom donors and can act in monodentate or bridging coordination modes in the construction of complexes. In addition, the bmi ligand can adopt different coordination conformations, resulting in complexes with different structures due to the presence of the flexible methylene spacer. Two new complexes, namely bis{1-[(benzotriazol-1-yl)methyl]-1H-1,3-imidazole-κN3}dibromidomercury(II), [HgBr2(C10H9N5)2], and bis{1-[(benzotriazol-1-yl)methyl]-1H-1,3-imidazole-κN3}diiodidomercury(II), [HgI2(C10H9N5)2], have been synthesized through the self-assembly of bmi with HgBr2 or HgI2. Single-crystal X-ray diffraction shows that both complexes are mononuclear structures, in which the bmi ligands coordinate to the HgII ions in monodentate modes. In the solid state, both complexes display three-dimensional networks formed by a combination of hydrogen bonds and π-π interactions. The IR spectra and PXRD patterns of both complexes have also been recorded.

9.
Environ Sci Pollut Res Int ; 24(9): 8392-8398, 2017 Mar.
Article in English | MEDLINE | ID: mdl-28185177

ABSTRACT

Abiotic stress factors, including ultraviolet (UV) radiation, significantly affect insect life. UV-A radiation (320-400 nm) has been widely used for insect control since it increases the production of ROS and causes oxidative cell damage. In the present study, we evaluated the effects of UV-A irradiation on an important pest in China, the ear-cutting caterpillar, Mythimna separata (Lepidoptera: Noctuidae). We exposed 3-day-old M. separata adults to UV-A radiation for different periods of time (0, 30, 60, 90, and 120 min) and evaluated the resulting total antioxidant capacity and the activity of the antioxidant enzymes superoxide dismutase, catalase, peroxidase, and glutathione-S-transferase. The total antioxidant capacity significantly increased after exposure to UV-A radiation for 60 min but decreased after 90 and 120 min of exposure, compared with the control. The antioxidant activity of glutathione-S-transferase, superoxide dismutase, catalase, and peroxidase increased after 60-min exposure, and it was decreased at the longest exposure period 120 min. The longest exposure time period relatively activates the xenobiotic detoxifying enzymes like glutathione-S-transferase, superoxide dismutase, catalase, and peroxidase enzymes. The longest duration of UV-A radiation may cooperate with pesticide detoxification mechanism in insects, making them more susceptible to insecticides. Our results demonstrated that UV irradiation causes oxidative stress, affects the activity of antioxidant enzymes, and disturbs the physiology of M. separata adults.


Subject(s)
Antioxidants/radiation effects , Moths/radiation effects , Oxidative Stress/radiation effects , Animals , Catalase/metabolism , China , Glutathione Transferase , Moths/enzymology , Oxidative Stress/drug effects , Peroxidases/metabolism , Superoxide Dismutase/metabolism , Ultraviolet Rays
10.
Acta Crystallogr C Struct Chem ; 73(Pt 2): 91-96, 2017 Feb 01.
Article in English | MEDLINE | ID: mdl-28157126

ABSTRACT

Subtle modifications of N-donor ligands can result in complexes with very different compositions and architectures. In the complex catena-poly[[bis{1-[(1H-benzotriazol-1-yl)methyl]-1H-imidazole-κN3}copper(II)]-µ-benzene-1,3-dicarboxylato-κ3O1,O1':O3], {[Cu(C8H4O4)(C10H9N5)2(H2O)]·2H2O}n, each CuII ion is six-coordinated by two N atoms from two crystallographically independent 1-[(1H-benzotriazol-1-yl)methyl]-1H-imidazole (bmi) ligands, by three O atoms from two symmetry-related benzene-1,3-dicarboxylate (bdic2-) ligands and by one water molecule, leading to a distorted CuN2O4 octahedral coordination environment. The CuII ions are connected by bridging bdic2- anions to generate a one-dimensional chain. The bmi ligands coordinate to the CuII ions in monodentate modes and are pendant on opposite sides of the main chain. In the crystal, the chains are linked by O-H...O and O-H...N hydrogen bonds, as well as by π-π interactions, into a three-dimensional network. A thermogravimetric analysis was carried out and the fluorescence behaviour of the complex was also investigated.

11.
Acta Crystallogr C Struct Chem ; 72(Pt 12): 1002-1006, 2016 Dec 01.
Article in English | MEDLINE | ID: mdl-27918303

ABSTRACT

The synthesis of coordination polymers or metal-organic frameworks (MOFs) has attracted considerable interest owing to the interesting structures and potential applications of these compounds. It is still a challenge to predict the exact structures and compositions of the final products. A new one-dimensional coordination polymer, catena-poly[[[bis{1-[(1H-benzimidazol-2-yl)methyl]-1H-tetrazole-κN3}zinc(II)]-µ-hexane-1,6-dicarboxylato-κ4O1,O1':O6,O6'] monohydrate], {[Zn(C6H8O4)(C9H8N6)2]·H2O}n, has been synthesized by the reaction of Zn(Ac)2 (Ac is acetate) with 1-[(1H-benzimidazol-2-yl)methyl]-1H-tetrazole (bimt) and adipic acid (H2adi) at room temperature. In the polymer, each ZnII ion exhibits an irregular octahedral ZnN2O4 coordination geometry and is coordinated by two N atoms from two symmetry-related bimt ligands and four O atoms from two symmetry-related dianionic adipate ligands. ZnII ions are connected by adipate ligands into a one-dimensional chain which runs parallel to the c axis. The bimt ligands coordinate to the ZnII ions in a monodentate mode on both sides of the main chain. In the crystal, the one-dimensional chains are further connected through N-H...O hydrogen bonds, leading to a three-dimensional supramolecular architecture. In addition, the title polymer exhibits fluorescence, with emissions at 334 and 350 nm in the solid state at room temperature.

12.
Acta Crystallogr C Struct Chem ; 72(Pt 11): 917-922, 2016 Nov 01.
Article in English | MEDLINE | ID: mdl-27811435

ABSTRACT

Due to their strong coordination ability and the diversities of their coordination modes, N-heterocyclic organic compounds are used extensively as ligands for the construction of complexes with fascinating structures and potential applications in many fields. Two new complexes, namely bis{1-[(benzotriazol-1-yl)methyl]-1H-imidazole-κN3}dibromidozinc(II), [ZnBr2(C10H9N5)2], (I), and bis{1-[(benzotriazol-1-yl)methyl]-1H-imidazole-κN3}diiodidozinc(II), [ZnI2(C10H9N5)2], (II), have been synthesized by reaction of the unsymmetrical N-heterocyclic ligand 1-[(benzotriazol-1-yl)methyl]-1H-imidazole (bmi) with Zn(acetate)2 in the presence of KBr or KI. Single-crystal X-ray diffraction analysis shows that both complexes exhibit a mononuclear structure, in which the bmi ligands coordinate to the central metal ion in a monodentate mode. In the solid state, both complexes possess a three-dimensional network formed by hydrogen bonds and π-π interactions. In addition, the IR spectroscopic properties, PXRD patterns and fluorescence properties of both complexes have been investigated.

13.
Acta Crystallogr C Struct Chem ; 72(Pt 6): 480-4, 2016 06 01.
Article in English | MEDLINE | ID: mdl-27256695

ABSTRACT

The N-heterocyclic ligand 2-[(1H-imidazol-1-yl)methyl]-1H-benzimidazole (imb) has a rich variety of coordination modes and can lead to polymers with intriguing structures and interesting properties. In the coordination polymer catena-poly[[cadmium(II)-bis[µ-benzene-1,2-dicarboxylato-κ(4)O(1),O(1'):O(2),O(2')]-cadmium(II)-bis{µ-2-[(1H-imidazol-1-yl)methyl]-1H-benzimidazole}-κ(2)N(2):N(3);κ(2)N(3):N(2)] dimethylformamide disolvate], {[Cd(C8H4O4)(C11H10N4)]·C3H7NO}n, (I), each Cd(II) ion exhibits an irregular octahedral CdO4N2 coordination geometry and is coordinated by four O atoms from two symmetry-related benzene-1,2-dicarboxylate (1,2-bdic(2-)) ligands and two N atoms from two symmetry-related imb ligands. Two Cd(II) ions are connected by two benzene-1,2-dicarboxylate ligands to generate a binuclear [Cd2(1,2-bdic)2] unit. The binuclear units are further connected into a one-dimensional chain by pairs of bridging imb ligands. These one-dimensional chains are further connected through N-H...O hydrogen bonds and π-π interactions, leading to a two-dimensional layered structure. The dimethylformamide solvent molecules are organized in dimeric pairs via weak interactions. In addition, the title polymer exhibits good fluorescence properties in the solid state at room temperature.

14.
Environ Sci Pollut Res Int ; 23(17): 17002-7, 2016 Sep.
Article in English | MEDLINE | ID: mdl-27206749

ABSTRACT

The ultraviolet light (UV-A) range of 320-400 nm is widely used as light trap for insect pests. Present investigation was aimed to determine the effect of UV light-A radiation on development, adult longevity, reproduction, and development of F1 generation of Mythimna separata. Our results revealed that the mortality of the second instar larvae was higher than the third and fourth instar larvae after UV-A radiation. As the time of UV-A irradiation for pupae prolonged, the rate of adult emergence reduced. Along with the extension of radiation time decreased the longevity of adult females and males. However, the radiation exposure of 1 and 4 h/day increased fecundity of female adults, and a significant difference was observed in a 1 h/day group. The oviposition rates of female adults in all the treatments were significantly higher than the control. In addition, UV-A radiation treatments resulted in declined cumulative survival of F1 immature stages (eggs, larvae, and pupae). After exposure time of 4 and 7 h/day, the developmental periods of F1 larvae increased significantly, but no significant effects on F1 pupal period were recorded.


Subject(s)
Fertility/radiation effects , Moths/radiation effects , Stress, Physiological/radiation effects , Ultraviolet Rays , Animals , Larva/drug effects , Oviposition/radiation effects , Pupa/drug effects
15.
Acta Crystallogr C Struct Chem ; 71(Pt 11): 1017-21, 2015 Nov.
Article in English | MEDLINE | ID: mdl-26524177

ABSTRACT

Multidentate N-heterocyclic compounds form a variety of metal complexes with many intriguing structures and interesting properties. The title coordination polymer, catena-poly[zinc(II)-bis{µ-2-[(1H-imidazol-1-yl)methyl]-1H-benzimidazole}-κ(2)N(3):N(3');N(3'):N(3)-zinc(II)-bis(µ-benzene-1,2-dicarboxylato)-κ(2)O(1):O(2);κ(3)O(1),O(1'):O(2)], [Zn2(C8H4O4)2(C11H10N4)2]n, has been synthesized by the reaction of Zn(NO3)2 with 2-[(1H-imidazol-1-yl)methyl]-1H-benzimidazole (imb) and benzene-1,2-dicarboxylic acid (H2bdic) under hydrothermal conditions. There are two crystallographically distinct imb ligands [imb(A) and imb(B)] in the structure which adopt very similar coordination geometries. The imb(A) ligand bridges two symmetry-related Zn1 ions, yielding a binuclear [(Zn1)2{imb(A)}2] unit, and the imb(B) ligand bridges two symmetry-related Zn2 ions resulting in a binuclear [(Zn2)2{imb(B)}2] unit. The above-mentioned binuclear units are further connected alternately by pairs of bridging bdic(2-) ligands, forming an infinite one-dimensional chain. These one-dimensional chains are further connected through N-H···O hydrogen bonds, leading to a two-dimensional layered structure. In addition, the title polymer exhibits good fluorescence properties in the solid state at room temperature.

16.
Acta Crystallogr C Struct Chem ; 71(Pt 8): 701-5, 2015 Aug.
Article in English | MEDLINE | ID: mdl-26243418

ABSTRACT

In the coordination polymer, poly[[{µ-1-[(1H-benzimidazol-2-yl)methyl]-1H-imidazole-κ(2)N:N'}(µ-5-carboxybenzene-1,3-dicarboxylato-κ(2)O(1):O(3))zinc(II)] dimethylformamide monosolvate pentahydrate], {[Zn(C9H4O6)(C11H10N4)]·C3H7NO·5H2O}n, the Zn(II) ion is coordinated by two N atoms from two symmetry-related 1-[(1H-benzimidazol-2-yl)methyl]-1H-imidazole (bmi) ligands and two O atoms from two symmetry-related 5-carboxybenzene-1,3-dicarboxylate (Hbtc(2-)) ligands in a slightly distorted tetrahedral geometry. The Zn(II) ions are bridged by Hbtc(2-) and bmi ligands, leading to a 4-connected two-dimensional network with the topological notation (4(4).6(2)). Adjacent layers are further connected by 12 kinds of hydrogen bonds and also by π-π interactions, resulting in a three-dimensional supramolecular architecture in the solid state.

17.
Acta Crystallogr C Struct Chem ; 71(Pt 6): 474-8, 2015 Jun.
Article in English | MEDLINE | ID: mdl-26044329

ABSTRACT

The combination of N-heterocyclic and multicarboxylate ligands is a good choice for the construction of metal-organic frameworks. In the title coordination polymer, poly[bis{µ2-1-[(1H-benzimidazol-2-yl)methyl]-1H-tetrazole-κ(2)N(3):N(4)}(µ4-butanedioato-κ(4)O(1):O(1'):O(4):O(4'))(µ2-butanedioato-κ(2)O(1):O(4))dicadmium], [Cd(C4H4O4)(C9H8N6)]n, each Cd(II) ion exhibits an irregular octahedral CdO4N2 coordination geometry and is coordinated by four O atoms from three carboxylate groups of three succinate (butanedioate) ligands and two N atoms from two 1-[(1H-benzimidazol-2-yl)methyl]-1H-tetrazole (bimt) ligands. Cd(II) ions are connected by two kinds of crystallographically independent succinate ligands to generate a two-dimensional layered structure with bimt ligands located on each side of the layer. Adjacent layers are further connected by hydrogen bonding, leading to a three-dimensional supramolecular architecture in the solid state. Thermogravimetric analysis of the title polymer shows that it is stable up to 529 K and then loses weight from 529 to 918 K, corresponding to the decomposition of the bimt ligands and succinate groups. The polymer exhibits a strong fluorescence emission in the solid state at room temperature.


Subject(s)
Benzimidazoles/chemistry , Cadmium/chemistry , Coordination Complexes/chemistry , Polymers/chemistry , Tetrazoles/chemistry , Crystallography, X-Ray , Fluorescence , Hydrogen Bonding , Ligands , Molecular Structure , Temperature
18.
Acta Crystallogr C Struct Chem ; 71(Pt 4): 306-10, 2015 Apr.
Article in English | MEDLINE | ID: mdl-25836291

ABSTRACT

In the title coordination polymer, catena-poly[[bis[{1-[(1H-benzimidazol-2-yl-κN(3))methyl]-1H-tetrazole}zinc(II)]-bis(µ4-pentane-1,5-dioato-1:2:1':2'κ(4)O(1):O(1'):O(5):O(5'))] methanol disolvate], {[Zn(C5H6O4)(C9H8N6)]·CH3OH}n, each Zn(II) ion is five-coordinated by four O atoms from four glutarate ligands and by one N atom from a 1-[(1H-benzimidazol-2-yl)methyl]-1H-tetrazole (bimt) ligand, leading to a slightly distorted square-pyramidal coordination environment. Two Zn(II) ions are linked by four bridging glutarate carboxylate groups to generate a dinuclear [Zn2(CO2)4] paddle-wheel unit. The dinuclear units are further connected into a one-dimensional chain via the glutarate ligands. The bimt ligands coordinate to the Zn(II) ions in a monodentate mode and are pendant on both sides of the main chain. In the crystal, the chains are linked by O-H···O and N-H···O hydrogen bonds into a two-dimensional layered structure. Adjacent layers are further packed into a three-dimensional network through van der Waals forces. A thermogravimetric analysis was carried out and the photoluminescent behaviour of the polymer was investigated.

19.
Insect Sci ; 22(4): 560-8, 2015 Aug.
Article in English | MEDLINE | ID: mdl-24963824

ABSTRACT

Due to the omnipresent risk of predation, termites have evolved many antipredatory behaviors. The two related species Reticulitermes speratus and R. chinensis have been demonstrated to use homosexual tandem running to decrease individual predation risk after shedding their wings. In this study, we tested risk of predation in the termite R. flaviceps, which is distantly related to the above two species. We determined that homosexual tandem running also led to low individual predation risk in dealates of R. flaviceps. Moreover, by combining a predation model with a competition model, we observed a typical trade-off phenomenon between antipredatory behavior and pairing competition produced by male-male tandem running in the above three Reticulitermes species. Our results indicated that male-male tandem running could effectively protect disadvantaged individuals from being caught, but disadvantaged individuals would be easily eliminated in pairing competition after male-male tandem running, suggesting that male-male tandem running can promote population evolution in termites by repeatedly removing the relatively inferior male individuals.


Subject(s)
Isoptera/physiology , Animals , Ants/physiology , Female , Male , Models, Theoretical , Predatory Behavior , Running , Sexual Behavior, Animal , Social Behavior
20.
Acta Crystallogr C ; 69(Pt 11): 1322-7, 2013 Nov.
Article in English | MEDLINE | ID: mdl-24192181

ABSTRACT

Two new inorganic-organic coordination polymers, namely poly[[µ6-2-(4-{1-[4-(carboxymethoxy)phenyl]-1-methylethyl}phenoxy)acetato][µ4-2-(4-{1-[4-(carboxymethoxy)phenyl]-1-methylethyl}phenoxy)acetato]disodium(I)], [Na2(C19H19O6)2]n, (I), and poly[hexa-µ-aqua-diaquabis{µ3-2,2'-[sulfonylbis(1,4-phenyleneoxy)]diacetato}tetrasodium(I)], [Na4(C16H14O8)2(H2O)8]n, (II), have been prepared. In (I), the asymmetric unit contains two Na(I) cations and two 2-(4-{1-[4-(carboxymethoxy)phenyl]-1-methylethyl}phenoxy)acetate (HL1(-)) ligands. Each Na(I) cation is octahedrally coordinated by two ether O atoms and four carboxylate O atoms of three different HL1(-) ligands. The NaO6 polyhedra share edges to form an inorganic ribbon along the a axis. These inorganic ribbons are further connected by the HL1(-) ligands to generate two-dimensional layers parallel to the (001) plane. The structure of (II) consists of ribbons of four crystallographically independent Na atoms (three six- and one five-coordinate), which are bridged by carboxylate O atoms of 4,4'-[sulfonylbis(1,4-phenyleneoxy)]diacetate (L2(2-)) ligands and water molecules. These ribbons are interlinked by L2(2-) ligands through two different coordination modes to afford a three-dimensional network.

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