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Purpose As a major sugar crop, sugar beet (Beta vulgaris L.) plays an important role in both sugar industry and feed products. Soil, acts as the substrate for plant growth, provides not only nutrients to plants but also a habitat for soil microorganisms. High soil fertility and good micro-ecological environment are basic requirements for obtaining high-yield and high-sugar sugar beets. This study aimed at exploring the effects of continuous cropping of sugar beet on its endophytic, soil bacterial community structures, and diversity. Methods Using high-throughput sequencing technology which is based on Illumina Hiseq 2500 platform, the seeds of sugar beet (sample S), non-continuous cropping sugar beet (sample Bn) with its rhizosphere soil (sample Sr), and planting soil (sample Sn), continuous cropping sugar beet (sample Bc) with its planting soil (sample Sc), were collected as research materials. Result The results showed that the bacterial communities and diversity in each sample exhibited different OTU richness; 67.9% and 63.8% of total endophytic OTUs from samples Bc and Bn shared with their planting soil samples Sc and Sn, while sharing 36.4% and 31.8% of total OTUs with their seed sample S. Pseudarthrobacter and Bacillus as the two major groups coexisted among all samples, and other shared groups belonged to Achromobacter, Sphingomonas, Novosphingobium, Terribacillus, Planococcus, Paracoccus, Nesterenkonia, Halomonas, and Nocardioides. Genera, including Pantoea, Pseudomonas, Stenotrophomonas, Weissella, Leuconostoc, and Acinetobacter, were detected in each sugar beet sample but not in their corresponding soil sample. In this study, the bacterial community structures and soil compositions have significantly changed before and after continuous cropping; however, the effects of continuous cropping on endophytic bacteria of sugar beet were not statistically significant. Conclusion This study would provide a scientific basis and reference information for in-depth research on correlations between continuous cropping and micro-ecological environment of sugar beet plant.

Background: In recent years, nanoparticles have been widely used in many fields, ranging from cosmetics, agriculture, environment, and biomedical areas. The increasing use of nanoproducts induces a potential increasing exposure to human body, and then, unknown pathological consequences could increase. Methods: The database was searched from 2008 to 2018 by the Web of Science Core Collection. The bibliometric methods, CiteSpace and HistCite, were used for analysis and visualization of the data. Results: The 2932 publications were analyzed and the annual publications grew from 78 to 512 in a decade. The United States and China mainly contribute to this research area, which accounted for 29.5% and 22.9%, respectively. PLoS One, Scientific Reports, and Nanoscale were the three journals that published the most articles. Keyword analysis indicated that the major research direction was the mechanisms of nanoneurotoxicity, which included oxidative stress, inflammation, astrocyte activation, and the fibrillation of amyloid β protein. Conclusion: This bibliometric study revealed that nanoneurotoxicity was still a research hot topic and could be a promising area of research in the next few years. Nanoparticles play a role in neurodegenerative diseases by inducing reactive oxygen species production, inflammation, alterations of gene expression, and signal pathways.

Super hybrid rice is one of the important research achievements in the field of rice super-high yield breeding in China. Compared with general high-yield rice, the yield potential of super hybrid rice is relatively high, and the average yields per hectare can exceed 10.5 t. This study aimed to study the endophytic bacterial community among a super hybrid rice combination and its parental lines and to reveal the potential relationship and association of endophytic bacteria between rice genotypes and their genetic relevance. In this research, through high-throughput sequencing based on Illumina Hiseq 2500 platform, the seeds of super hybrid rice variety ‘Shenliangyou 5814’ (sample C) and its parental lines ‘Y58S’ (sample M) and ‘C4114’ (sample F) independently cultivated by China were used as plant materials to study their endophytic bacterial structure and diversity. The number of OTUs for sample M, F and C was 327, 288 and 283 respectively, and among them 218 endophytic OTUs coexisted in the 3 samples. Pantoea (18.6–31.1%) was the first dominant groups shared in all three samples, and other dominant shared groups belonged to Methylobacterium (4.48%~17.65%), Sphingomonas (4.0%~11.4%), Rhizobium (5.69–8.78%), Microbacterium (3.85%~9.41%) and Pseudomonas (4.13%~5.68%). Although Principal Coordinates Analysis (PCoA) and Non-metric Multidimensional Scaling (NMDS) analysis showed that there were obvious differences in endophytic bacterial community composition and structure among the 3 samples, the dominant endophytic bacterial genus sample C and its parental lines remained consistency. This study would provide scientific clues for the future research on the vertical transmission of endophytes between rice generations.

Asteroid exploration has become one of the important ways to understand the origin of the universe, exploit the space mineral resources and protect the earth from the asteroid impact. The imaging spectrometer, which can acquire the spatial and spectral information simultaneously, has become one of the most important payloads for the asteroid exploration. In this paper, the optical design of a broadband Offner imaging spectrometer for the asteroid exploration is presented. It covers from 0.4μm to 3μm, and the F/# is 6 and 3 for the VNIR band (0.4μm-1.0μm) and the SWIR band (1.0μm -3.0μm), respectively. The convex grating in the imaging spectrometer is divided into two regions of different groove spacing, and each region is optimized with different blazed angles to improve the spectral response of this imaging spectrometer. The diffraction efficiency is analyzed with the Comsol software and the result is greater than 0.36 in the wavelength range of 0.4μm to 3μm. After optimized with the optical design software, the diameter of the imaging spectrometer's spot diagram is less than one pixel, and the lowest MTF is 0.460 at the Nyquist frequency. The smile and keystone is less than 10% of the pixel.

The purpose of this experiment was to analyze the microbial community diversity in three Daqu samples displaying different characteristics in the same Daqu fermentation chamber. A high throughput sequencing technique was used to detect the microbial abundance and diversity in these Daqu samples. Of the three samples, the microbial diversity in the Black sample (sample B) was significantly higher than in the other two. At the genus level, Saccharopolyspora, Bacillus, Lentibacillus, Staphylococcus, Kroppenstedtia, and Thermoactinomyces were the primary bacterial groups in the sesame-flavored liquor, while Thermomyces, Thermoascus, and Aspergillus represented the main fungal groups. In sample B, the dominant bacteria were Thermoactinomyces, Saccharopolyspora, and Pseudomonas. In the White sample (sample W), Thermoactinomyces was the most abundant, followed by Saccharopolyspora and Lentibacillus. Staphylococcus dominated in the Yellow sample (sample Y), followed by Bacillus and Kroppenstedtia. Regarding the fungi in the three samples, Thermomyces accounted for 93.70% in sample B, and Aspergillus dominated in sample W, while the Thermoascus and Aspergillus content were similar in the sample Y. This study examined the microbial diversity in liquor Daqu with different sesame flavors, providing a foundation for microbial regulation, while investigating the relationship between flavored liquor compounds and microorganisms. ELECTRONIC SUPPLEMENTARY MATERIAL: The online version of this article (10.1007/s13205-020-02500-1) contains supplementary material, which is available to authorized users.

This research aimed to investigate the composition and diversity of endophytic bacterial community in seeds of four hybrid maize and their parental lines, which was used to reveal the potential relationship and association of endophytic bacteria between maize genotypes and their genetic relevance. High-throughput sequencing (HTS) technology showed that a total of 1419 OTUs (46.6%) were parental lines unique and 1052 OTUs (34.5%) were hybrid varieties unique, with only 575 core OTUs revealed in all the samples. Most OTUs belonged to Proteobacteria. Enterobacter (23.2%), Shigella (21.2%), Pseudomonas (15.8%) and Achromobacter (10.1%) were the major genera; the bacterial community composition and diversity of endophytic bacteria were inconsistent among different seed genotypes. Based on principal component analysis (PCA), the results referred that the endophytic composition of hybrid sample showed obvious correlation with their female parental lines, and in ‘Jingke968’ and ‘MC738’ with the same female line the endophytic community was more similar than other hybrid samples. This was the first ever use of HTS technology for investigating the endophytic bacterial diversity and community structures in seeds of genetically related maize genotypes, it was shown that, there were core microbes shared among all genotypes of seed samples, and the female parental line was more significant to impact on the composition of their hybrid seeds than male parental line. This study would provide scientific clues for the future research on the vertical transmission of endophytes among maize generations. ELECTRONIC SUPPLEMENTARY MATERIAL: The online version of this article (10.1007/s13205-019-2034-8) contains supplementary material, which is available to authorized users.

Plant endophytes are microbes that colonize plant internal tissues and are ubiquitously associated with plants. In this study, seven endophytic bacterial strains, 665L2, 725L2, 725R2, 92R2, 728R3, 728R4 and 2416T3, were isolated from seeds of five healthy maize varieties (Zea mays L.) and all identified as Bacillus velezensis by polyphasic taxonomy based on 16S rRNA and gyrA gene phylogenetic analysis. In addition, according to the genotyping results from random amplified polymorphic DNA (RAPD), 665L2, 725L2, 725R2 and 92R2 belonged to the same strain, while 728R3 and 2416T3 belonged to another strain. Pathogenic fungal strains 4, 5 and 6 were isolated from three diseased maize varieties (Zea mays L.), and they were identified as Talaromyces funiculosus, Penicillium oxalicum and Fusarium verticillioides, respectively, by polyphasic taxonomy based on morphological identification, ITS rDNA and bio-control gene phylogenetic analyses. Seven endophytic bacterial Bacillus velezensis strains had favourable antagonistic activity, and antagonistic testing was carried out against the three pathogenic strains, Talaromyces funiculosus 4, Penicillium oxalicum 5 and Fusarium verticillioides 6. Biological control lipopeptide antibiotic genes (bioA, bmyB, ituC, fenD, srfAA, srfAB, yngG and yndJ) were amplified using specific primers, and they were found in the seven endophytic bacterial Bacillus velezensis strains. This study provides a scientific basis for future research on the use of resistant endophytic bacterial resources to enhance crop production.

Maize is a crop grown worldwide. Bacillus ciccensis 5L6T was isolated from maize (Zea mays L., Jingke968) seeds and was a new species of Bacillus with potential anti-fungal activity. The complete genome of 5L6T was sequenced and assembled with a length of 5,207,802 bp and a GC content of 37.42%. The proteins responsible for anti-fungal activity and the potential beneficial interaction with maize of 5L6Twere annotated and reported here. The complete genome sequence of the new species B. ciccensis 5L6T will promote its biological application.

AMP-activated protein kinase (AMPK) plays an important role in mediating energy metabolism and is controlled mainly by two upstream kinases, LKB1 or Ca(2+)/calmodulin-dependent protein kinase kinase-β (CaMKKβ). Previously, we found that baicalin, one of the major flavonoids in a traditional Chinese herb medicine, Scutellaria baicalensis, protects against the development of hepatic steatosis in rats feeding with a high-fat diet by the activation of AMPK, but, the underlying mechanism for AMPK activation is unknown. Here we show that in two LKB1-deficient cells, HeLa and A549 cells, baicalin activates AMPK by α Thr-172 phosphorylation and subsequent phosphorylation of its downstream target, acetyl CoA carboxylase, at Ser-79, to a similar degree as does in HepG2 cells (that express LKB1). Pharmacologic inhibition of CaMKKβ by its selective inhibitor STO-609 markedly inhibits baicalin-induced AMPK activation in both HeLa and HepG2 cells, indicating that CaMKKβ is the responsible AMPK kinase. We also show that treatment of baicalin causes a larger increase in intracellular Ca(2+) concentration ([Ca(2+)](i)), although the maximal level of [Ca(2+)](i) is lower in HepG2 cells compared to HeLa cells. Chelation of intracellular free Ca(2+) by EDTA and EGTA, or depletion of intracellular Ca(2+) stores by the endoplasmic reticulum Ca(2+)-ATPase inhibitor thapsigargin abrogates baicalin-induced activation of AMPK in HeLa cells. Neither cellular ATP nor the production of reactive oxygen species is altered by baicalin. Finally, in HeLa cells, baicalin treatment no longer decreases intracellular lipid accumulation caused by oleic acid after inhibition of CaMKKβ by STO-609. These results demonstrate that a potential Ca(2+)/CaMKKβ dependent pathway is involved in the activation of AMPK by baicalin and suggest that CaMKKβ likely acts as an upstream kinase of AMPK in response to baicalin.