Transcription Factor Mavib-1 Negatively Regulates Conidiation by Affecting Utilization of Carbon and Nitrogen Source in Metarhizium acridum

Conidium is the main infection unit and reproductive unit of pathogenic fungi. Exploring the mechanism of conidiation and its regulation contributes to understanding the pathogenicity of pathogenic fungi. Vib-1, a transcription factor, was reported to participate in the conidiation process. However, the regulation mechanism of Vib-1 in conidiation is still unclear. In this study, we analyzed the function of Vib-1 and its regulation mechanism in conidiation through knocking out and overexpression of Vib-1 in entomopathogenic fungus Metarhizium acridum. Results showed that the colonial growth of Mavib-1 disruption mutant (ΔMavib-1) was significantly decreased, and conidiation was earlier compared to wild type (WT), while overexpression of Mavib-1 led to a delayed conidiation especially when carbon or nitrogen sources were insufficient. Overexpression of Mavib-1 resulted in a conidiation pattern shift from microcycle conidiation to normal conidiation on nutrient-limited medium. These results indicated that Mavib-1 acted as a positive regulator in vegetative growth and a negative regulator in conidiation by affecting utilization of carbon and nitrogen sources in M. acridum. Transcription profile analysis demonstrated that many genes related to carbon and nitrogen source metabolisms were differentially expressed in ΔMavib-1 and OE strains compared to WT. Moreover, Mavib-1 affects the conidial germination, tolerance to UV-B and heat stresses, cell wall integrity, conidial surface morphology and conidial hydrophobicity in M. acridum. These findings unravel the regulatory mechanism of Mavib-1 in fungal growth and conidiation, and enrich the knowledge to conidiation pattern shift of filamentous fungi

Brassinolide Increases Potato Root Growth In Vitro in a Dose-Dependent Way and Alleviates Salinity Stress

Brassinosteroids (BRs) are steroidal phytohormones that regulate various physiological processes, such as root development and stress tolerance. In the present study, we showed that brassinolide (BL) affects potato root in vitro growth in a dose-dependent manner. Low BL concentrations (0.1 and 0.01 μg/L) promoted root elongation and lateral root development, whereas high BL concentrations (1–100 μg/L) inhibited root elongation. There was a significant (P<0.05) positive correlation between root activity and BL concentrations within a range from 0.01 to 100 μg/L, with the peak activity of 8.238 mg TTC·g−1 FW·h−1 at a BL concentration of 100 μg/L. Furthermore, plants treated with 50 μg/L BL showed enhanced salt stress tolerance through in vitro growth. Under this scenario, BL treatment enhanced the proline content and antioxidant enzymes’ (superoxide dismutase, peroxidase, and catalase) activity and reduced malondialdehyde content in potato shoots. Application of BL maintain K+ and Na+ homeostasis by improving tissue K+/Na+ ratio. Therefore, we suggested that the effects of BL on root development from stem fragments explants as well as on primary root development are dose-dependent and that BL application alleviates salt stress on potato by improving root activity, root/shoot ratio, and antioxidative capacity in shoots and maintaining K+/Na+ homeostasis in potato shoots and roots

Insights into post-magmatic metasomatism and Li circulation in granitic systems from phosphate minerals of the Nanping No. 31 pegmatite (SE China)

Phosphate minerals are key indicators for understanding the processes of diagenesis and mineralization in granitic systems. More importantly, these minerals provide constraints on the post-magmatic behaviour of Li in pegmatite systems that remain to be explored, although Li from early-crystallized Li phosphates is known to leach into hydrothermal fluids. In this study, we performed a detailed petrographic and compositional analysis of phosphate minerals from the Nanping No. 31 pegmatite in southeastern of China, which provides new evidence of Li circulation in granitic systems. Primary phosphate minerals evolved from xenotime and monazite to Mn-rich fluorapatite and then to triphylite and montebrasite, with large amounts of montebrasite in the intermediate zones of the pegmatite, reflecting the increasing activities of both Li and P in peraluminous granitic melts. Montebrasite experienced stages of both high-temperature (360–273 °C) and low-temperature (273–100 °C) hydrothermal alteration. The high-temperature hydrothermal alteration of montebrasite by Fe- and Mg-rich fluids resulted in the formation of a series of Fe-, Mg-bearing phosphates; the replacement of montebrasite under low-temperature alteration generated amounts of Ca-, Sr-, Ba-bearing phosphate minerals, muscovite and akdalaite (Al2O3)4·H2O. The formation of micro-networks of akdalaite from montebrasite indicate the low mobility of Al in hydrothermal fluids. A four-stage scenario of post-magmatic Li transport in the Nanping No. 31 pegmatite is proposed: (1) Li derived from the breakdown of primary montebrasite was locally recrystallized and produced secondary montebrasite (Mtb-1); (2) hydrothermal alteration by Fe- and Mg-bearing fluids leached Li from montebrasite to form secondary triphylite and simferite; (3) Li derived from the alteration of montebrasite by Sr-, Ca-rich fluids was involved in the formation of secondary palermoite and bertossaite; and (4) the replacement of secondary triphylite, montebrasite, palermoite and bertossaite by later phases (apatites, ludlamite, anapaite, augelite and fine-grained muscovite) reflect the leaching of Li back into hydrothermal fluids. The re-enrichment of Li during the post-magmatic stage most likely increased the solubility of Ta in the hydrothermal fluids of the granitic pegmatite. © 2017 Elsevier B.V

The Design and Experiment of Vertical Variable Cavity Base Fertilizer Fertilizing Apparatus

A vertical variable cavity organic fertilizer and compound fertilizer apparatus were designed according to tobacco farming requirements to overcome issues of unstable fertilizer discharge and blocking in the fertilizer disk of an existing fertilizer apparatus. The structure and working principle of the fertilizer apparatus were described. Combined with the principle of anti-arch and the requirements of fertilizer application, the structure size of the fertilizer apparatus was determined. Using the opening degree and rotational speed of the fertilizer disk as the test factors and the fertilizer rate and variation coefficient of fertilizer application rate as the indices, the EDEM was used to conduct the single factor test and obtain the appropriate rotational speed range. The results indicated that the variation coefficient of the fertilizer uniformity apparatus was 0.96&ndash;5.22% under different rotation speeds and fertilizer disk openings, which satisfied design requirements. The orthogonal experiment explored the interaction between rotational speed and the opening. The influence of the opening adjustment on the fertilizer application rate and the coefficient of variation of uniformity were greater than the change in fertilizer disk speed. The bench and field tests aligned with the simulation test. These findings provide a reference and theoretical basis to design a fertilizer apparatus

Synergistic Optimization of Buried Interface by Multifunctional Organic–Inorganic Complexes for Highly Efficient Planar Perovskite Solar Cells

Highlights Highly performed perovskite solar cells are achieved via introducing organic–inorganic CL–NH complex as multifunctional interfacial layer. CL–NH complex not only reduces oxygen vacancies on the surface of SnO2 but also regulates film crystallization, resulting in a superior device efficiency of 23.69%. The resulting device performs excellent stability with 91.5% initial power conversion efficiency retained after 500 h light illumination

High Performance Liquid Chromatography Determination and Optimization of the Extraction Process for the Total Alkaloids from Traditional Herb <i>Stephania cepharantha</i> Hayata

Stephania cepharantha Hayata is a traditional Chinese herbal medicine used to treat lung cancer, and its alkaloids, especially cepharanthine (CEP), were reported to be its effective ingredients. Therefore, the extraction of potential antitumor ingredients from the plant was of interest. We first explored the optimized solvent extraction of antitumor agents from S. cepharantha Hayata guided by an in vitro antitumor activity assay. The solvent for extraction and its concentration, the liquid to material ratio, extraction duration, particle size, macerating time, and the frequency of extraction were investigated using a single-factor experiment. An orthogonal design (L9, 34) was constructed to determine the suitable extraction conditions. The crude extract was then purified sequentially by macroporous adsorption resins (MR) for the enrichment of CEP. Under these optimal conditions, the yield of total alkaloids in the herbs was 3.4%, whereas the CEP content was 2.9%. Total alkaloids exhibited significant anti-proliferative activities in the A549 cell line. Our study provides means for the further development and use of the antitumor components from S. cepharantha, which has potential for application in the pharmaceutical industry

Additional file 1: Table S1. of Extract of Ginkgo biloba exacerbates liver metastasis in a mouse colon cancer Xenograft model

List of primers for PCR. Table S2 List of antibodies. (DOCX 17 kb