Clay nanosheet-mediated delivery of recombinant plasmids expressing artificial miRNAs via leaf spray to prevent infection by plant DNA viruses

Whitefly-transmitted begomoviruses are economically important plant pathogens that cause severe problems in many crop plants,such as tomato,papaya,cotton,and tobacco.Tomato yellow leaf curl virus(TYLCV)is a typical monopartite begomovirus that has been extensively studied,but methods that can efficiently control begomoviruses are still scarce.In this study,we combined artificial microRNA(amiRNA)-mediated silencing technology and clay nanosheetmediated delivery by spraying and developed a method for efficiently preventing TYLCV infection in tomato plants.We designed three amiRNAs that target different regions of TYLCV to silence virus-produced transcripts.Three plant expression vectors expressing pre-amiRNAs were constructed,and recombinant plasmid DNAs(pDNAs)were loaded onto nontoxic and degradable layered double hydroxide(LDH)clay nanosheets.LDH nanosheets containing multiple pDNAs were sprayed onto plant leaves.We found that the designed amiRNAs were significantly accumulated in leaves 7 days after spraying,while the pDNAs were sustainably detected for 35 days after the spray,suggesting that the LDH nanosheets released pDNAs in a sustained manner,protected pDNAs from degradation and efficiently delivered pDNAs into plant cells.Importantly,when the LDH nanosheets coated with pDNAs were sprayed onto plants infected by TYLCV,both the disease severity and TYLCV viral concentration in sprayed plants were significantly decreased during the 35 days,while the levels of H_(2)O_(2) were significantly increased in those plants.Taken together,these results indicate that LDH nanosheets loaded with pDNAs expressing amiRNAs can be a sustainable and promising tool for begomovirus control.

High-quality draft genome sequence of Streptomyces agglomeratus 5-1-8 with strong anti-MRSA ability, isolated from the frozen soil of Tibet in China

Streptomyces agglomeratus 5-1-8 with strong anti methicillin-resistant Staphylococcus aureus(MRSA)ability,isolated from the frozen soil of Tibet in China,has a strong ability to kill the multi-drugs-resistant MRSA.To identify the second-ary metabolism ability of this strain,we describe here the phenotypic characteristics of this strain,along with its high-quality draft genome sequence,its annotation,and analysis.The 7.1M draft genome encodes 6,284 putative open reading frames(ORFs),of which 4,416 ORFs were assigned with clusters of orthologous genes(COG)categories.Also,65 t RNA genes and 24 r RNA operons were identified.The genome contains 12 gene clusters involved in antibiotics production and 1 gene cluster involved in anticancer-compounds production;4 gene clusters belong to polyketides and nonribosomal peptides,1gene cluster belong to the butyrolactone,4 gene clusters belong to the bacteriocin or lantipeptide,and 3 gene clusters belong to the others.This genome-sequence data will facilitate efforts to probe the potential of new antibiotics to kill multidrugs-resistant MRSA.

The interaction mechanism and the functionality of yeast protein with hydrophilic and hydrophobic bioactive molecules

Yeast protein is a kind of yeast-source high-quality complete protein.The coexistence of bioactive molecules with yeast protein may influence its physicochemical property.This study discussed the interaction mechanism of yeast protein with two bioactive molecules,the hydrophobic curcumin and the hydrophilic epigallocatechin gallate(EGCG).Results indicated that curcumin and EGCG could interact with yeast protein with different binding stoichiometric numbers(0.8109±0.0695 and 2.7248±0.2422)and binding constants((3.8152±0.0078)×10^(4) and(1.1875±0.0440)×10^(5)),respectively.Both EGCG and curcumin decreased theα-helix content while increased theβ-sheet proportion,and co-binding remarkably reduced theα-helix proportion relative to the single ligand binding.The co-binding of these two compounds decreased the association extent of the yeast protein,which in turn reduced the diameter of yeast protein-EGCG-curcumin complex.The binding of EGCG with yeast protein improved the thermal stability of curcumin.Moreover,the co-binding improved the emulsification stability of yeast protein,and curcumin exhibited a more remarkable effect in improving the foamability.This work provides a theoretical basis for clarifying the interaction mechanisms of hydrophobic/hydrophilic molecules with yeast protein,and extends the potential applications of the novel fungus protein sources for food function enhancement and bioactive molecule stabilization.

Fenton-like degradation of Methylene Blue using paper mill sludge-derived magnetically separable heterogeneous catalyst:Characterization and mechanism

For the paper industry, the disposal and management of the yielded sludge are a considerable challenge. In our work, the paper mill sludge-derived magnetically separable heterogeneous catalyst（PMS-Fe-380） was prepared easily through a facile synthesis method. The morphology and structure of PMS-Fe-380 were fully characterized by means of X-ray diffraction, Fourier transform infrared spectroscopy, scanning electron microscopy, and Brunauer–Emmet–Teller analysis. The catalytic activity of PMS-Fe-380 was evaluated by degradation of Methylene Blue（MB）. The reusability and stability of PMS-Fe-380 were evaluated in five repeated runs, which suggested that PMS-Fe-380 manifested excellent stability of catalytic activity. Moreover,leaching tests indicated that the leached iron is negligible（〈0.5 mg/L）. This study provides an alternative environmentally friendly reuse method for paper mill sludge and a novel catalyst PMS-Fe-380 that can be considered as a promising heterogeneous Fenton-like catalyst.

HLA-B-associated transcript 3 (Bat3) stabilizes and activates p53 in a HAUSP-dependent manner

The p53 pathway is a highly complex signaling network including several key regulators.HAUSP is a critical component of the p53 pathway acting as a deubiquitinase for both p53 and its key repressor Mdm2.Here,we identified a novel HAUSP-interacting protein,HLA-B-associated transcript 3(Bat3)and found it to be capable of inducing p53 stabilization and activation via a HAUSP-dependent mechanism,resulting in cell growth inhibition.Surprisingly,the deubiquitylating enzymatic activity of HAUSP was not required for this phenomenon.Co-immunoprecipitation showed that p53 coexisted in a complex with Bat3 and HAUSP in vivo,and HAUSP may serve as a binding mediator to enhance the interaction between p53 and Bat3.Further studies revealed that formation of this three-protein complex interfered with the binding of p53 to its proteasome receptor S5a and promoted the accumulation of p53 in nucleus.Notably,Mdm2 protein abundance is also regulated by Bat3 in the presence of HAUSP.Overexpression of Bat3 and HAUSP increases Mdm2 protein levels without influencing the p53–Mdm2 interaction and Mdm2-mediated p53 ubiquitination,indicating that Bat3–HAUSP-mediated protein stabilization is not specific to p53 and different mechanisms may be involved in Bat3-mediated regulation of p53–Mdm2 pathway.Together,our study unravels a novel mechanism by which p53 is stabilized and activated by HAUSP-mediated interaction with Bat3 and implies that Bat3 might function as a tumor suppressor through the stabilization of p53.