An immunochromatographic test strip for on-site detection of Ralstonia solanacearum in tobacco leaves and soil.

Tobacco bacterial wilt is one of the most devastating soil-borne diseases in tobacco-producing regions worldwide. It is often responsible for significant economic losses during tobacco production. A rapid, specific, and high-throughput on-site detection method is important for plant disease management. In this study, monoclonal antibody 3H3 and polyclonal antibody 0344 specific for Ralstonia solanacearum were used to prepare a colloidal gold-based immunochromatographic test strip (ITS). Under optimal conditions, the detection limit of the ITS was 105 CFU/mL. The ITS was able to detect different R. solanacearum strains collected from Shandong, Yunnan, Guizhou, and Sichuan provinces in China. Moreover, the ITS was highly specific for R. solanacearum, with no cross-reactivity with Alternaria alternata (Fries) Keissler, Pseudomonas syringae pv. angulata, and P. syringae pv. tabaci. Furthermore, R. solanacearum-spiked tobacco leaves and soil were used to evaluate the matrix interference of the developed ITS, which indicated the test strip was unaffected by leaf size or soil abundance.

Key anti-freeze genes and pathways of Lanzhou lily (Lilium davidii, var. unicolor) during the seedling stage.

Temperature is one of the most important environmental factors for plant growth, as low-temperature freezing damage seriously affects the yield and distribution of plants. The Lanzhou lily (Lilium davidii, var. unicolor) is a famous ornamental plant with high ornamental value. Using an Illumina HiSeq transcriptome sequencing platform, sequencing was conducted on Lanzhou lilies exposed to two different temperature conditions: a normal temperature treatment at 20°C (A) and a cold treatment at -4°C (C). After being treated for 24 hours, a total of 5848 differentially expressed genes (DEGs) were identified, including 3478 significantly up regulated genes and 2370 significantly down regulated genes, accounting for 10.27% of the total number of DEGs. Quantitative real-time PCR (QRT-PCR) analysis showed that the expression trends of 10 randomly selected DEGs coincided with the results of high-throughput sequencing. In addition, genes responding to low-temperature stress were analyzed using the interaction regulatory network method. The anti-freeze pathway of Lanzhou lily was found to involve the photosynthetic and metabolic pathways, and the key freezing resistance genes were the OLEO3 gene, 9 CBF family genes, and C2H2 transcription factor c117817_g1 (ZFP). This lays the foundation for revealing the underlying mechanism of the molecular anti-freeze mechanism in Lanzhou lily.

Physiological and transcriptomic responses of Lanzhou Lily (Lilium davidii, var. unicolor) to cold stress.

Low temperature induces changes in plants at physiological and molecular levels, thus affecting growth and development. The Lanzhou lily (Lilium davidii, var. unicolor) is an important medicinal plant with high economic value. However, the molecular mechanisms underlying its photosynthetic and antioxidation responses to low temperature still remain poorly understood. This study subjected the Lanzhou lily to the two temperatures of 20°C (control) and 4°C (low temperature) for 24 h. Physiological parameters related to membrane integrity, photosynthesis, antioxidant system, and differentially expressed genes were investigated. Compared with control, low temperature increased the relative electrical conductivity by 43.2%, while it decreased net photosynthesis rate, ratio of variable to maximal fluorescence, and catalase activity by 47.3%, 10.1%, and 11.1%, respectively. In addition, low temperature significantly increased the content of soluble protein, soluble sugar, and proline, as well as the activity of superoxide dismutase and peroxidase. Comparative transcriptome profiling showed that a total of 238,109 differentially expressed genes were detected. Among these, 3,566 were significantly upregulated while 2,982 were significantly downregulated in response to low temperature. Gene Ontology enrichment analysis indicated that in response to low temperature, the mostly significantly enriched differentially expressed genes were mainly involved in phosphorylation, membrane and protein kinase activity, as well as photosynthesis, light harvesting, light reaction, and alpha,alpha-trehalose-phosphate synthase activity. Kyoto Encyclopedia of Genes and Genomes enrichment analysis also indicated that the most significantly enriched pathways involved ribosome biogenesis in eukaryotes, phenylalanine metabolism, circadian rhythm, porphyrin and chlorophyll metabolism, photosynthesis of antenna proteins, photosynthesis, and carbon fixation in photosynthetic organisms. Moreover, the expression patterns of 10 randomly selected differentially expressed genes confirmed the RNA-Seq results. These results expand the understanding of the physiological and molecular mechanisms underlying the response of the Lanzhou lily to low temperature stress.

Uniform small-sized MoS2 from novel solution-based microwave-assisted method with exceptional reversible lithium storage properties.

Currently, MoS2 is being investigated as a lithium-ion battery (LIB) anode material because of its high theoretical capacity. However, its significantly low electrochemical activity and cyclic stability limit its utilization. Nevertheless, small-sized MoS2 possibly overcomes these issues. Herein, small-sized MoS2 with uniform particle sizes of about 20-30 nm was prepared via a novel solution-based microwave-assisted precursor pyrolysis method. The resultant MW-MoS2 sample has a high surface area of 96.9 m2 g-1 and large pore volume (0.38 cm3 g-1) with pore size distribution mainly in the meso/macropore scale, which are beneficial for electrolyte storage and low charge carrier conductive resistances. The large pore surface area and volume of the small-sized MoS2 can also ease the volume expansion during the charging and discharging process. As an LIB anode, the MW-MoS2 material exhibits an amazingly large specific capacity of 1355 mA h g-1 at a low current density of 0.5 A g-1. At a high current density of 10 A g-1, a specific capacity of 435 mA h g-1 is obtained, demonstrating its excellent rate capability. Furthermore, a large discharge capacity of 544 mA h g-1 is maintained after 500 cycles at 5 A g-1, indicating its fascinatingly high cyclic stability.

A Large-Sized Reduced Graphene Oxide with Low Charge-Transfer Resistance as a High-Performance Electrode for a Nonflammable High-Temperature Stable Ionic-Liquid-Based Supercapacitor.

Large-sized reduced graphene oxide prepared was prepared by combined microwave intermittent heating and an extraction process (e.g., 900 W for 10 min (MRG-900-10)) with a lateral size of several micrometers and a thickness of 4-6 monosheets . The MRG-900-10 has a high C/O molar ratio (5.89) and a sp2 C content of 69.0 %, which leads to a fast electronic transmission in the sample. In addition, MRG-900-10 possesses a large specific surface area of 568.2 m2 g-1 , which increases the contact surface area between the active material and the electrolyte, thus enhancing the electron and ion transport in the interfaces when used as the electrode material in supercapacitors. MRG-900-10 possesses a low charge-transfer resistance (≈0.36 Ω). Used as the electrode material for a supercapacitor in 6 m KOH aqueous electrolyte, MRG-900-10 produces a high specific capacity of 327.6 F g-1 at the current density of 0.5 A g-1 . A specific capacity of 248.3 F g-1 was obtained at a high current density of 100 A g-1 , which indicated its high-rate ability. The initial capacity of 92 % can be maintained after 40 000 cycles at 5 A g-1 , which indicated its high cycling stability. As for the MRG-900-10 symmetric supercapacitors, the energy densities of 11.0 and 36.2 Wh kg-1 were obtained in 6 m KOH aqueous and 1 m tetraethylammonium tetrafluoroborate ([TEA]BF4 )/acetonitrile (ACN) electrolytes, respectively. Importantly, a high energy density of 68.6 Wh kg-1 was achieved in the nonflammable ionic liquid 1-ethyl-3-methylimidazolium bis(trifluoromethane)sulfonimide ([EMIM][TFSI])/ACN (80 vol % [EMIM][TFSI]), and the supercapacitor was effective from room temperature to 100 °C.

Binary Hierarchical Porous Graphene/Pyrolytic Carbon Nanocomposite Matrix Loaded with Sulfur as a High-Performance Li-S Battery Cathode.

A N,O-codoped hierarchical porous nanocomposite consisting of binary reduced graphene oxide and pyrolytic carbon (rGO/PC) from chitosan is fabricated. The optimized rGO/PC possesses micropores with size distribution concentrated around 1.1 nm and plenty of meso/macropores. The Brunauer-Emmett-Teller specific surface area is 480.8 m2 g-1, and it possesses impressively large pore volume of 2.14 cm3 g-1. On the basis of the synergistic effects of the following main factors: (i) the confined space effect in the hierarchical porous binary carbonaceous matrix; (ii) the anchor effects by strong chemical bonds with codoped N and O atoms; and (iii) the good flexibility and conductivity of rGO, the rGO/PC/S holding 75 wt % S exhibits high performance as Li-S battery cathode. Specific capacity of 1625 mA h g-1 can be delivered at 0.1 C (1 C = 1675 mA g-1), whereas 848 mA h g-1 can be maintained after 300 cycles at 1 C. Even at high rate of 5 C, 412 mA h g-1 can be restrained after 1000 cycles.