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Black spot disease caused by Ceratocystis fimbriata is destructive to the production, transportation, and storage of sweet potato. The antifungal effects of Bacillus tequilensis XK29 against C. fimbriata through volatile organic compounds (VOCs) were evaluated in this study. The activated carbon assay proved that XK29 could exert antibiotic effects through volatiles. By optimizing the wheat seed weight, inoculation method, concentration, volume, and time, the antifungal activity of XK29 was significantly improved. XK29 fumigation inhibited spore formation and germination and changed the cell morphology of C. fimbriata. During the storage of sweet potato tuber roots, XK29 effectively controlled black spot disease and reduced the weight loss and malondialdehyde content. Metabolomic analysis revealed that 21 volatile compounds were released from XK29. Isovaleric acid, isobutyric acid, and 2-methylbutanoic acid effectively inhibited the growth of C. fimbriata. These results indicate that B. tequilensis XK29 has a good potential to be developed as a microbial fumigation agent.

Arctium lappa L. is one of the medicinal and food homologous plants in China, which is rich in nutrients and medicinal ingredients. The use of plant growth-promoting (PGP) endophytic bacteria is an alternative to reducing chemical fertilizers in agricultural production. The aim of this study was to analyze the diversity of endophytic bacteria in different cultivars of A. lappa L. collected from two geographical locations in China and evaluate PGP traits of the isolates and their potential PGP ability in greenhouse condition. Endophytic bacterial community was investigated by culture-dependent and culture-independent methods. Isolates were screened and investigated for multiple PGP traits, and representative strains were inoculated host seedlings to evaluate the growth promoting effect. A total of 348 endophytic bacteria were obtained and they were distributed into 4 phyla and 30 genera. In addition, high throughput sequencing revealed more abundant bacterial community, including 17 bacterial phyla and 207 genera. A high proportion of PGP traits were detected, including production of indole acetic acid, siderophore, ammonia and phosphate solubilization. Four representative strains with multiple PGP traits of the most dominant genera (Bacillus, Pantoea, Microbacterium and Pseudomonas) were further selected for host inoculation and growth promoting evaluation, and they significantly increase seedlings length, root length and fresh weight. This study demonstrated that A. lappa L. harbors abundant endophytic bacteria, and some endophytic bacteria showed good potential for the development of microbial fertilizer in the future.

Volatile organic compounds (VOCs) produced by microorganisms are considered promising environmental-safety fumigants for controlling postharvest diseases. Ceratocystis fimbriata, the pathogen of black spot disease, seriously affects the quality and yield of sweet potato in the field and postharvest. This study tested the effects of VOCs produced by Streptomyces setonii WY228 on the control of C. fimbriata in vitro and in vivo. The VOCs exhibited strong antifungal activity and significantly inhibited the growth of C. fimbriata. During the 20-day storage, VOC fumigation significantly controlled the occurrence of the pathogen, increased the content of antioxidants and defense-related enzymes and flavonoids, and boosted the starch content so as to maintain the quality of the sweet potatoes. Headspace analysis showed that the volatiles 2-ethyl-5-methylpyrazine and dimethyl disulfide significantly inhibited the mycelial growth and spore germination of C. fimbriata in a dose-dependent manner. Fumigation with 100 μL/L 2-ethyl-5-methylpyrazine completely controlled the pathogen in vivo after 10 days of storage. Transcriptome analysis showed that volatiles mainly downregulated the ribosomal synthesis genes and activated the proteasome system of the pathogen in response to VOC stress, while the genes related to spore development, cell membrane synthesis, mitochondrial function, and hydrolase and toxin synthesis were also downregulated, indicating that WY228-produced VOCs have diverse modes of action for pathogen control. Our study demonstrates that fumigation of sweet potato tuberous roots with S. setonii WY228 or use of formulations based on the VOCs is a promising new strategy to control sweet potato and other food and fruit pathogens during storage and shipment. IMPORTANCE Black spot disease caused by Ceratocystis fimbriata has caused huge economic losses to worldwide sweet potato production. At present, the control of C. fimbriata mainly depends on toxic fungicides, and there is a lack of effective alternative strategies. The research on biological control of sweet potato black spot disease is also very limited. An efficient biocontrol technique against pathogens using microbial volatile organic compounds could be an alternative method to control this disease. Our study revealed the significant biological control effect of volatile organic compounds of Streptomyces setonii WY228 on black spot disease of postharvest sweet potato and the complex antifungal mechanism against C. fimbriata. Our data demonstrated that Streptomyces setonii WY228 and its volatile 2-ethyl-5-methylpyrazine could be a candidate strain and compound for the creation of fumigants and showed the important potential of biotechnology applications in the field of food and agriculture.

Pseudomonas chlororaphis subsp. aureofaciens SPS-41 is a plant growth–promoting rhizobacterium with biocontrol potential that was isolated from the rhizosphere of sweet potato in Xuzhou, Jiangsu Province, China. Our previous study demonstrated that volatile organic compounds (VOCs) produced by SPS-41 inhibited black spot disease fungi Ceratocystis fimbriata in postharvest sweet potatoes and a variety of other plant pathogens, and the VOCs also displayed strong nematocidal activity. In order to further explore the application potential of this strain, we here report the complete genome sequence of strain SPS-41. The genome consists of one chromosome (6,757,898 bp) with a G+C content 63.10%, which contains 5,951 coding genes, 67 transfer RNA genes, 16 ribosome RNA genes, and 85 other non-coding RNA genes. No plasmid was detected. The information of the genome will provide resources for studying the biocontrol mechanism of this strain. [Formula: see text] Copyright © 2021 The Author(s). This is an open access article distributed under the CC BY-NC-ND 4.0 International license .

Advantage distillation (AD) provides a means of separating highly correlated raw key bits from weakly correlated information in quantum key distribution (QKD). In this Letter, we apply the AD method to improve the performance of reference-frame-independent QKD (RFI-QKD). Simulation results show that, compared with RFI-QKD without AD, RFI-QKD with AD can tolerate higher system errors and obtain better performance on the secret key rate and transmission distance. Furthermore, we extend the AD method to RFI measurement-device-independent QKD (RFI-MDI-QKD) and demonstrate that the AD method can improve the performance of RFI-MDI-QKD more significantly.

We present an erratum to our Letter [Opt. Lett. 47, 4219 (2022)10.1364/OL.470558]. This erratum corrects the error results of Figs. 2 and 4 due to the error in the simulation code. The corrections have no influence on the conclusions of the original Letter.

Purpose Arctium lappa L. is one of the medicinal and food homologous plants in China, which is rich in nutrients and medicinal ingredients. The use of plant growth promoting (PGP) endophytic bacteria is a useful alternative in agricultural production to reduce the use of chemical fertilizers. The aim of this study was to analysis the diversity of endophytic bacteria in different cultivars of A. lappa L. collected from two different geographical locations in China and evaluate PGP traits of the isolates and their potential PGP ability in greenhouse condition. Methods Endophytic bacterial community was investigated by culture-dependent and culture-independent methods. Isolates were screened and investigated for multiple PGP traits, and representative strains were inoculated host seedlings to evaluate the growth promoting effect. Results A total of 348 endophytic bacteria were obtained and they distributed into four phyla, 30 genera and 73 different species. In addition, high throughput sequencing revealed more abundant bacterial community, including 17 bacterial phyla, and 207 different known genera. A high proportion of PGP traits were detected, including production of indole acetic acid, siderophore, ammonia and phosphate solubilization. Four representative strains with multiple PGP traits of the most prevalent genera were further selected for host inoculation and growth promoting evaluation, and they significantly increase seedlings length, root length and fresh weight. Conclusion This study demonstrated that A. lappa L. harbors abundant endophytic bacteria, and plant genotype and geographical origin affect their composition. Moreover, some endophytic bacteria showed good potential for the development of microbial fertilizer in the future.

Soil salinity stress affects the health and growth of crops. The use of plant growth-promoting rhizobacteria (PGPR) to improve the salt tolerance of plants is gaining acceptance worldwide. Here, a halotolerant, plant growth-promoting actinobacterium Glutamicibacter halophytocola KLBMP 5180, recently isolated from the root of a coastal halophyte Limonium sinense, was investigated for its capacity on the growth of tomato seedlings under the condition of saline stress. Tomato seedlings were inoculated with strain KLBMP 5180 and irrigated with 2% NaCl salt-stress treatment. Plant growth and physiological responses were determined after harvest. The genome of strain KLBMP 5180 was sequenced and analyzed. High salinity significantly reduced the growth and biomass of tomato seedlings. However, KLBMP 5180 inoculation significantly improved tomato growth in terms of seedling fresh weight and height, root length and fresh weight, and number of fibrous roots, along with increased osmolyte content (proline) and antioxidant defense enzymes and regulation of ion homeostasis under salt stress. From the genome, we identified a series of genes that may contribute to plant growth promotion, including genes for nitrogen fixation, biosynthesis of siderophores and exopolysaccharides. Additionally, several genes related to high salinity tolerance, such as Na+/H+ antiporter, K+ transporter, glycine-betaine synthesis and transport, and several heavy metal resistance and biodegradation genes were also identified in the genome of strain KLBMP 5180. Our results demonstrate that the halotolerant strain KLBMP 5180 can be used to improve tomato seedling growth in saline soil and act as a potential agricultural biofertilizer agent in future applications.

Objective To explore the effects of self-directed learning readiness and learning attitude on problem-solving ability among Chinese undergraduate nursing students. Methods A convenience sampling of 460 undergraduate nursing students was surveyed in Tianjin, China. Students who participated in the study completed a questionnaire that included social demographic questionnaire, Self-directed Learning Readiness Scale, Attitude to Learning Scale, and Social Problem-Solving Inventory. Pearson’s correlation analysis was performed to test the correlations among problem-solving ability, self-directed learning readiness, and learning attitude. Hierarchical linear regression analyses were performed to explore the mediating role of learning attitude. Results The results showed that learning attitude (r=0.338, Pr=0.493, PF=74.227, P Conclusions It is concluded that nursing educators should pay attention on students’ individual differences and take proper actions to inspire students’ self-directed learning readiness and learning attitude.

The biocontrol activity and chemical composition of the volatile organic compounds (VOCs) produced by Pseudomonas chlororaphis subsp. aureofaciens SPS-41 were investigated. The VOCs inhibited mycelial growth and spore germination in Ceratocystis fimbriata, which causes black rot disease in sweet potato tuber roots (TRs) and showed wide-spectrum antifungal activity against several plant pathogenic fungi. A microscopic examination of C. fimbriata cells suggested morphological changes and a loss of cellular contents. Different inoculation strategies significantly affected the antifungal activity of the VOCs. In the volatile profile of SPS-41, the most abundant compound, 3-methyl-1-butanol, followed by phenylethyl alcohol and 2-methyl-1-butanol showed strong inhibition toward C. fimbriata. The weight loss rate and disease severity of the TRs were significantly reduced in response to the VOCs emitted by SPS-41. The results suggest that the VOCs produced by P. chlororaphis subsp. aureofaciens SPS-41 might constitute an attractive biological fumigant for controlling black rot disease in sweet potato TRs.

To improve the maximal transmission distance and the maximal error rate tolerance, we apply the advantage distillation technology to analyze security of the practical decoy-sate quantum key distribution system. Based on the practical experimental parameters, the device-dependent quantum key distribution protocols and the measurement-device-independent quantum key distribution protocols have been respectively analyzed, and our analysis results demonstrate that the advantage distillation technology can significantly improve the performance of different quantum key distribution protocols. In the four-state and six-state device-dependent quantum key distribution protocols, we prove that the maximal transmission distance can be improved from 142 km to 180 km and from 146 km to 187 km respectively. In the four-state and six-state measurement-device-independent quantum key distribution protocols, we prove that the maximal transmission distance can be improved from 195 km to 273 km and from 200 km to 282 km respectively. More interestingly, the advantage distillation technology does not need to change the hardware devices about the quantum step, thus it can be conveniently to be applied in various practical quantum key distribution systems.

OBJECTIVES To systematically evaluate the efficacy of auricular acupressure on sleep disorders, depression, pruritus, xerostomia and daily net weight gain (%) in maintenance haemodialysis patients. BACKGROUND Auricular acupressure has been used for various complications in maintenance haemodialysis patients, such as sleep disorders, depression, pruritus and xerostomia, but the efficacy has not yet been unified. DESIGN Systematic review and meta-analysis. METHODS Randomised controlled trials comparing auricular acupressure intervention with non-AA intervention in maintenance haemodialysis patients were included. We searched English databases (PubMed, Cochrane Library, Embase, Web of Science) and Chinese databases (CNKI, WanFang, CBM and VIP database) from the inception to 27 November 2020. The risk of bias was assessed by the Cochrane risk of bias tool. The RevMan 5.3 software was used to perform the meta-analysis. A descriptive analysis was conducted if the data were high of heterogeneity or could not be meta-analysed. The PRISMA statement was used to report systematic review and meta-analysis. RESULTS A total of 12 RCTs with 805 MHD patients were included. Meta-analysis showed that auricular acupressure had a significant difference for improving sleep disorders (MD = -1.97 points, 95% CI: -2.62 to -1.32, p