Identification and Expression Profiles of Putative Soluble Chemoreception Proteins from Lasioderma serricorne (Coleoptera: Anobiidae) Antennal Transcriptome.

The cigarette beetle, Lasioderma serricorne (Fabricius) (Coleoptera: Anobiidae), is a destructive stored product pest worldwide. Adult cigarette beetles are known to rely on host volatiles and pheromones to locate suitable habitats for oviposition and mating, respectively. However, little is known about the chemosensory mechanisms of these pests. Soluble chemoreception proteins are believed to initiate olfactory signal transduction in insects, which play important roles in host searching and mating behaviors. In this study, we sequenced the antennal transcriptome of L. serricorne and identified 14 odorant-binding proteins (OBPs), 5 chemosensory proteins (CSPs), and 2 Niemann-Pick C2 proteins (NPC2). Quantitative realtime PCR (qPCR) results revealed that several genes (LserOBP2, 3, 6, and 14) were predominantly expressed in females, which might be involved in specific functions in this gender. The five LserOBPs (LserOBP1, 4, 8, 10, and 12) that were highly expressed in the male antennae might encode proteins involved in specific functions in males. These findings will contribute to a better understanding of the olfactory system in this stored product pest and will assist in the development of efficient and environmentally friendly strategies for controlling L. serricorne.

Quantitative proteomics revealed partial fungistatic mechanism of ammonia against conidial germination of nematode-trapping fungus Arthrobotrys oligospora ATCC24927.

Ammonia is one of the fungistatic factors in soil that can suppress conidial germination, but the molecular mechanism underlying the suppression is unknown. In this study, the proteomes of fungistatic conidia, fresh conidia and germinated conidia of Arthrobotrys oligospora ATCC24927 were determined and quantified. The protein expression profile of fungistatic conidia was significantly different from those in the other two conditions. 281 proteins were down expressed in fungistatic conidia and characterized by GO annotation. Gene transcription analysis and inhibition of puromycin (a protein translation inhibitor) on conidial germination suggested that down expression of 33 protein translation related proteins might well result in repression of protein synthesis and inhibition of conidial germination. In addition, 16 down-expressed proteins were mapped to the Ras/mitogen-activated protein (Ras/MAP) regulatory networks which regulate conidial DNA synthesis. The conidial DNA synthesis was found to be definitely inhibited under by ammonia, and function studies of two Ras/MAP proteins by using knock-out strains provided partial evidence that Ras/MAP pathway regulate the conidial germination. These results suggested that down-expression of Ras/MAP related proteins might result in inhibition of DNA synthesis and finally result in inhibition conidial germination. This study revealed partial fungistatic mechanism of ammonia against conidial germination.

Bacillus endozanthoxylicus sp. nov., an endophytic bacterium isolated from Zanthoxylum bungeanum Maxim leaves.

A Gram-stain-positive, rod-shaped, motile bacterium, designated as 1404T, was isolated from leaves of Chinese red pepper (Huajiao) (Zanthoxylum bungeanum Maxim) collected from Gansu, north-west China. Spores were not observed under a range of conditions. Strain 1404T was observed to grow at 15-45 °C and pH 6.0-10.0 and in presence of 0-5 % (w/v) NaCl concentration. The cell wall of strain 1404T was found to contain meso-diaminopimelic acid, and the predominant respiratory quinone was identified as MK-7. The major polar lipids were diphosphatidylglycerol, phosphatidylglycerol, phosphatidylethanolamine and an unidentified phospholipid as well as three unidentified polar lipids. The major fatty acids profile of strain 1404T consisted of iso-C15 : 0 (25.6 %), anteiso-C15 : 0 (18.4 %) and iso-C14 : 0 (12.1 %). Phylogenetic analysis based on 16S rRNA gene sequences indicated that strain 1404T was affiliated to the genus Bacillus and was closely related to Bacillusoryzisoli 1DS3-10T, Bacillusbenzoevorans DSM 5391T and Bacilluscirculans DSM 11T with sequence similarity of 98.3, 98.2 and 96.9 %, respectively. The G+C content of the genomic DNA was determined to be 39.4 mol%. DNA-DNA hybridization values indicated that relatedness between strain 1404T and the type strains of closely related species of the genus Bacillus was below 41 %. Therefore, on the basis of the data from the polyphasic taxonomic study presented, strain 1404T represents a novel species of the genus Bacillus, for which the name proposed is Bacillus endozanthoxylicus sp. nov. The type strain is 1404T (=CCTCC AB 2017021T=KCTC 33827T).

Isolation and characterisation of rhizosphere bacteria active against Meloidogyne incognita, Phytophthora nicotianae and the root knot-black shank complex in tobacco.

BACKGROUND: The use of dually antagonistic bacteria (DAB) as alternatives to chemicals for biological control of disease complexes has received little attention. In this study targeting the Meloidogyne incognita-Phytophthora nicotianae complex, DAB from the tobacco rhizosphere were identified and screened against the diseases caused by one or both pathogens in tobacco. RESULTS: From 450 soil tobacco rhizosphere samples, 26 DAB were identified and had in vitro nematicidal and antifungal efficacies of 37.2-100% and 32.9-73.4% respectively. These DAB were classified into 19 species of 11 genera. In pot experiments, Streptomyces flavofungini SNA26, Pseudomonas putida SNB53 and Serratia marcescens subsp. sakuensis SNB54 effectively suppressed black shank (control effect 72.0-80.2%), root knot (70.0-81.7) and the disease complex (58.7-68.5%) caused by P. nicotianae, M. incognita and both pathogens in tobacco respectively. CONCLUSION: Nineteen DAB species were demonstrated to be antagonists against the M. incognita-P. nicotianae complex. Because S. flavofungini SNA26, P. putida SNB53 and S. marcescens subsp. sakuensis SNB54 significantly suppressed the infection of M. incognita and P. nicotianae in tobacco, these species have potential for development as biocontrol agents against the diseases and complex caused by these two pathogens.

Sphingobacterium nematocida sp. nov., a nematicidal endophytic bacterium isolated from tobacco.

A novel Gram-negative strain, designated M-SX103(T), was isolated from a fresh leaf of Nicotiana tabacum Linn. collected at Yuxi City, Yunnan province, China, and subjected to a polyphasic taxonomic study. Growth occurred at 10-40 °C, at pH 6.0-9.0 and with 0-3% (w/v) NaCl. The predominant isoprenoid quinone was MK-7. The major cellular fatty acids of strain M-SX103(T) were iso-C(15:0), iso-C(17:0) 3-OH and summed feature 3 (C(16:1)ω7c and/or C(16:1)ω6c). The G+C content of the genomic DNA was 40.6 mol%. Phylogenetic analysis based on 16S rRNA gene sequences showed that the isolate belongs to the genus Sphingobacterium, sharing 95.4-89.7% sequence similarity with type strains of members of the genus Sphingobacterium; it was most closely related to Sphingobacterium composti T5-12(T). On the basis of the taxonomic evidence, a novel species, Sphingobacterium nematocida sp. nov., is proposed. The type strain is M-SX103(T) ( = JCM 17339(T) = CCTCC AB 2010390(T)).