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Zhang H.,Chinese Academy of Agricultural Sciences | Yang S.,Chinese Academy of Agricultural Sciences | Yang S.,Natural History Research Center | Gong H.,Chinese Academy of Agricultural Sciences | And 4 more authors.
Parasitology Research | Year: 2015

Ticks encounter various microbes while sucking blood from an infected host and carrying these pathogens in themselves. Ticks can then transmit these pathogens to vertebrate hosts. The immune system of ticks can be stimulated to produce many bioactive molecules during feeding and pathogen invasion. Antimicrobial peptides (AMPs) are key effector molecules of a tick’s immune response, as they can kill invading pathogenic microorganisms. In this study, we identified a novel cysteine-rich AMP, designated Rhamp1, in the salivary glands of unfed and fed female ticks (Rhipicephalus haemaphysaloides). Rhamp1 is encoded by a gene with an open reading frame of 333 bp, which in turn encodes a peptide of 12 kDa with a 22 amino acid residue signal peptide. The Rhamp1 protein had a pI of 8.6 and contained six conserved cysteine residues at the C-terminus. Rhamp1 shared 43 % amino acid identity with a secreted cysteine-rich protein of another tick species, Ixodes scapularis. We cloned the Rhamp1 gene and attempted to express a recombinant protein using prokaryotic and eukaryotic systems, to determine its biological significance. Recombinant Rhamp1 was successfully expressed in both systems, yielding a glutathione S-transferase (GST)-tagged protein (36 kDa) from the prokaryotic system, and a polyhistidine-tagged Rhamp1 protein (14 kDa) from the eukaryotic system. Rhamp1 inhibited the activities of chymotrypsin (16 %) and elastase (22 %) and exerted low hemolytic activity. It also inhibited the growth of Gram-negative bacteria, including Pseudomonas aeruginosa (49 %), Salmonella typhimurium (50 %), and Escherichia coli (52 %). Our findings suggest that Rhamp1 is a novel AMP in R. haemaphysaloides with the ability to inhibit proteinase activity. © 2015, Springer-Verlag Berlin Heidelberg.

Bu Y.,Natural History Research Center | Bu Y.,CAS Shanghai Institutes for Biological Sciences | Ma Y.,CAS Shanghai Institutes for Biological Sciences | Ma Y.,University of Chinese Academy of Sciences | Luan Y.-X.,CAS Shanghai Institutes for Biological Sciences
ZooKeys | Year: 2016

The genus Paracerella Imadaté, 1980 is recorded from China for the first time, with the description of a new species, Paracerella sinensis sp. n. Paracerella sinensis is characterized by four pairs of A-setae on tergite I, the presence of setae Pc and P3a on tergite VII, eight A-setae on tergite VIII, the presence of seta Pc on both sternites VI and VII, and 4/2 setae on sternite VIII, which are different from all other members of the genus. The key to the four species of the genus is updated. In addition, DNA barcodes of four populations are sequenced and their genetic differences are analyzed. © Yun Bu et al.

Bu Y.,Natural History Research Center | Gao Y.,Shanghai Hengjie Chemical Co.
ZooKeys | Year: 2015

The genus Paratullbergia Womersley, 1930 is recorded for the first time from China. Paratullbergia changfengensis sp. n. from Shanghai is described and illustrated. It is characterized by the presence of 1+1 pseudocelli on thoracic segment I, with two pairs of pseudocelli on each of thoracic segments II and III, presence of seta px on abdominal segment IV, seta a2 and p4 on abdominal segment V as microsetae, and less differentiated sensory seta p3 on abdominal segment V. Both sexes present. The new species can be easily distinguished from its congeners by the presence of pseudocelli on thoracic segment I. An updated key to the world species of the genus Paratullbergia is provided. © Yun Bu, Yan Gao.

Wang Q.,Lanzhou University | Wang X.J.,Natural History Research Center | Hang L.,Lanzhou University | Zhang Y.F.,Natural History Research Center | And 2 more authors.
Shengtai Xuebao/ Acta Ecologica Sinica | Year: 2016

Arbuscular mycorrhizal (AM) fungi are one of the most important rhizosphere microorganisms in agro- ecosystems. It has been demonstrated that symbiosis with AM fungi can enhance the growth of host plants by improving water and nutrient absorption and increasing their tolerance ability to stress conditions. However, the positive effects of symbiosis with AM are usually being limited by the application of chemical fertilizers, pesticides, and other agronomic practices in traditional farming systems. In order to produce safe foods and maintain the balance of the natural environment, organic farming without the use of chemical fertilizers or pesticides has been practiced all over the world, and increasing attention has focused on the role of AM fungi in organic farming systems. The aim of this review was to present the advantages and enhance the application of AM fungi in organic farming systems. AM fungi influenced the physical structure of soil, alleviated environmental stress damage, increased nutrient acquisition and biomass production, and improved the quality of crop products by the external hyphae. We also discussed and analyzed the challenges of AM fungi application in organic farming systems. Based on the above, AM fungi could promote the development of organic farming in the future. © 2015, Ecological Society of China. All rights reserved.

Jin L.,Natural History Research Center | Jin L.,Lanzhou University | Sun L.,Lanzhou University | Wang Q.,Lanzhou University | And 4 more authors.
Shengtai Xuebao/ Acta Ecologica Sinica | Year: 2016

Arbuscular mycorrhizal (AM) fungi are important soil microorganisms, which can form symbioses with more than 80% of vascular plants in terrestrial ecosystems. It has been demonstrated that AM fungi could improve the growth of host plants through regulation of their physiological and biochemical characteristics. In light of this, AM fungi could regulate plant intra-and inter-specific competition in natural habitats. Recently, using AM fungi to protect plant biodiversity and maintain plant community stability in grassland ecosystems has generated much interest. Here, the functions of AM fungi are discussed at the autecology, population, community and ecosystem levels in order to discover the relationship between AM fungi and host plants. There are three different responses of individual host plants to AM fungi symbiosis, including positive, negative and neutral effects. At the population and community levels, AM fungi could regulate intra- and inter-specific competition by influencing the transportation of nutrients and water among individuals, such as to regulate herbaceous and poisonous plant populations. AM fungi also could maintain plant community structures and plant diversity in grasslands by regulating the plant competition. At the ecosystem level, AM fungi could promote the process of community succession, and thus could be used in bioremediation of damaged ecosystems. This review aims to provide theories and methods for the protection of grassland ecosystems by integrating the uses of AM fungi. © 2016, Ecological Society of China. All rights reserved.

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