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.

Way to efficient microbial paclitaxel mass production

The microbial synthesis of paclitaxel is attractive for its short-cycle,cost-effectiveness,and sustainability.However,low paclitaxel productivity,depleted capacity during subculture and storage,and unclear biosynthesis mechanisms restrain industrial microbial synthesis.Along with the isolation of various paclitaxel-producing microorganisms and the development of versatile molecular tools,tremendous promises for microbial paclitaxel synthesis have become increasingly prominent.In this review,we summarize the progress of microbial synthesis of paclitaxel in recent years,focusing on paclitaxel-producing endophytes and representative engineering microorganism hosts that were used as chassis for paclitaxel precursor synthesis.Numerous wide-type microbes can manufacture paclitaxel,and fermentation process optimization and strain improvement can greatly enhance the productivity.Engineered microbes can efficiently synthesize precursors of paclitaxel by introducing exogenous synthetic pathway.Mining paclitaxel synthetic pathways and genetic manipulation of endophytes will accelerate the construction of microbial cell factories,indefinitely contributing to paclitaxel mass production by microbes.This review emphasizes the potential and provides solutions for efficient microbial paclitaxel mass production.

NDRG1 promotes endothelial dysfunction and hypoxia-induced pulmonary hypertension by targeting TAF15

Background:Pulmonary hypertension(PH)represents a threatening pathophysiologic state that can be induced by chronic hypoxia and is characterized by extensive vascular remodeling.However,the mechanism underlying hypoxia-induced vascular remodeling is not fully elucidated.Methods and Results:By using quantitative polymerase chain reactions,western blotting,and immunohistochemistry,we demon-strate that the expression of N-myc downstream regulated gene-1(NDRG1)is markedly increased in hypoxia-stimulated endothelial cells in a time-dependent manner as well as in human and rat endothelium lesions.To determine the role of NDRG1 in endothelial dysfunction,we performed loss-of-function studies using NDRG1 short hairpin RNAs and NDRG1 over-expression plasmids.In vitro,silencing NDRG1 attenuated proliferation,migration,and tube formation of human pulmonary artery endothelial cells(HPAECs)un-der hypoxia,while NDRG1 over-expression promoted these behaviors of HPAECs.Mechanistically,NDRG1 can directly interact with TATA-box binding protein associated factor 15(TAF15)and promote its nuclear localization.Knockdown of TAF15 abrogated the effect of NDRG1 on the proliferation,migration and tube formation capacity of HPAECs.Bioinformatics studies found that TAF15 was involved in regulating PI3K-Akt,p53,and hypoxia-inducible factor 1(HIF-1)signaling pathways,which have been proved to be PH-related pathways.In addition,vascular remodeling and right ventricular hypertrophy induced by hypoxia were markedly alleviated in NDRG1 knock-down rats compared with their wild-type littermates.Conclusions:Taken together,our results indicate that hypoxia-induced upregulation of NDRG1 contributes to endothelial dysfunction through targeting TAF15,which ultimately contributes to the development of hypoxia-induced PH.

Elderly smart medicine box based on NB_IOT

This paper will study and design a smart medicine box for the elderly based on NBIOT Internet of Things technology. The NBIOT has the characteristics of low power consumption, wide coverage and large number of connections, it supports the access of multiple intelligent medicine boxes in the same community[1].The set medication information is transmitted to the smart medicine box terminal through the NBIOT Internet of Things management platform, which sets the medication time and the medication dose. In order to prevent the mistake of taking medicine, the specifi ed medicine is opened by the medicine box electromagnetic lock device at the time of reaching the medication time, In order to remind the number of medications taken by the elderly during the medication, we use the voice module and the weighing module to provide services. At the same time, we installed a semiconductor refrigeration sheet in the medicine drawer of the medicine box, which can adjust the temperature of the medicine box to the set value to prevent the deterioration of the medicine. The experimental results of the medicine box showed that the smart medicine box of the old man has the characteristics of intelligence, stability, reliability and simple operation.