In this work, MWCNT-COOH-cellulose nanocomposite was prepared with MWCNT-COOH, SOCl2 as leaving group and cellulose as an adsorbent (A1); MgO nanoparticles have been successfully coated on the surface of nanocomposite by directly adding to A1 (MWCNT-COOH-cellulose-MgO; A2), magnesium nitrate was added to A1 and MgO nanoparticles were achieved by coating indirectly on the surfaces (MWCNT-COOH-cellulose-MgO; A3). These nanocomposites (A1, A2, and A3) were used for the removal of methyleneblue (MB) dye from aqueous solution. For characterization of adsorbent surfaces, the FT-IR, TEM, SEM, and XRD analysis were used. The effects of initial concentration of MB dye, contact time, and temperature on the adsorption were studied. According to the results, 55 min was selected as the optimum contact time for the removal process. The equilibrium data of adsorption were well fitted and the Langmuir (type III) model had the best agreement because it possesses high value of linear regression, high value R 2 , and least value of average relative error, ARE (%). Parameters of thermodynamics including enthalpy (∆H°), entropy (∆S°), and Gibbs energy (∆G°) were calculated. Kinetic data had best agreement with pseudo-second-order model. Graphical abstract Schematic synthesis of MWCNT-COOH-cellulose-MgO NP nanocomposite as adsorbent

Plastids from Nicotiana benthamiana were transformed with the vector for dicistronic expression of two genes-aminoglycoside 3'-adenyltransferase (aadA) and green fluorescent protein (gfp)-in the plastids of Nicotiana tabacum. Transplastomic shoots exhibited green fluorescence under UV light. Transformation efficiencies were similar between species. Although the border sequence (trnI and trnA) for homologous recombination to transform the plastid genome of N. benthamiana was identical to that sequence of N. tabacum, the exception was a 9-bp addition in the intron of trnI. This indicated that the N. tabacum sequence used as a border region for recombination was sufficient to insert the foreign gene into the target site between the trnI and trnA of N. benthamiana with similar efficiency. Southern blot analysis detected the presence of aadA and gfp between trnI and trnA in the plastid genome of N. benthamiana. Northern and western blot analyses revealed high expression of gfp in the plastids from petals and leaves. Our results suggest that the plastid transformation system established here is applicable to investigations of the interactions between plastid and nucleus in N. benthamiana.

RNA interference (RNAi) is an important phenomenon that has diverse genetic regulatory functions at the pre- and posttranscriptional levels. The major trigger for the RNAi pathway is double-stranded RNA (dsRNA). dsRNA is processed to generate various types of major small noncoding RNAs (ncRNAs) that include microRNAs (miRNAs), small interfering RNAs (siRNAs) and PIWI-interacting RNAs (piRNAs) in Drosophila melanogaster (D. melanogaster). Functionally, these small ncRNAs play critical roles in virtually all biological systems and developmental pathways. Identification and processing of dsRNAs and activation of RNAi machinery are the three major academic interests that surround RNAi research. Mechanistically, some of the important biological functions of RNAi are achieved through: (i) supporting genomic stability via degradation of foreign viral genomes; (ii) suppressing the movement of transposable elements and, most importantly, (iii) post-transcriptional regulation of gene expression by miRNAs that contribute to regulation of epigenetic modifications such as heterochromatin formation and genome imprinting. Here, we review various routes of small ncRNA biogenesis, as well as different RNAi-mediated pathways in D. melanogaster with a particular focus on signaling pathways. In addition, a critical discussion of the most relevant and latest findings that concern the significant contribution of small ncRNAs to the regulation of D. melanogaster physiology and pathophysiology is presented.

p19 protein encoded by tomato bushy stunt virus (TBSV) is known as a suppressor of RNA silencing via inhibition of small RNA-guided cleavage in plants. In this study, we generated TBSVp19-expressing patatin-RNAi transgenic potatoes to identify the inhibitory mechanisms of RNA silencing mediated by TBSVp19. In TBSVp19-expressing patatin-RNAi lines, reduction of patatin-derived siRNA accumulation and complementation of patatin transcripts were detected in comparison with the non-TBSVp19-expressing patatin-RNAi line, suggesting that TBSVp19 suppresses the siRNA-mediated silencing pathway. Interestingly, no apparent effect on the accumulation of miRNA168 and other miRNAs was detected in TBSVp19-expressing lines; previous studies reported that p19 induced the accumulation of both miRNA168 and its target Argonaute 1 (AGO1) mRNA, but suppressed AGO1 translation via up-regulation of miRNA168 in Arabidopsis. In addition, the expression of Argonaute 1 (AGO1-1 and AGO1-2) and Dicer-like 1 (DCL1) was not significantly altered in p19-expressing lines. Interestingly, no translational inhibition of AGO1 mediated by p19 was detected. These results suggest that p19 suppresses siRNA-mediated silencing in potato, but may not affect miRNA-mediated silencing, possibly due to the host-dependent manner of p19 activity.

At the beginning of 2020, a new type of Coronavirus (Severe Acute Respiratory Syndrome Coronavirus -2 (SARS-CoV-2)) dismayed the world and led to public health emergencies. This virus has caused a remarkable percentage of morbidity and mortality. Also, the lack of an effective treatment to fight this virus is another concern that should be given attention. Herbal medicines and purified natural products have been reported for their antiviral activity against SARS-CoV-2. In this study, molecular docking of effective compounds in the extracts and essential oils of Zingiber officinale, Glycyrrhiza glabra Sambucus nigra, Panax ginseng Ocimum basilicum, and Origanum vulgare was carried out to investigate their binding to the X-ray structure of the ACE2 binding domain of SARS-CoV-2. The Glide docking program was utilized for molecular docking with standard precision (SP) and extra precision (XP). Finally, 7 compounds- mainly belong to Panax ginseng-showed a higher docking score than some known antiviral compounds. Floralginsenoside B, which is extracted from Panax ginseng, indicated a strong binding affinity (-8.618 kcal/mol) to the crucial residues of the receptor binding domain of SARS-CoV-2 comparing to Doravirine (-7.2 kcal/mol), Hetacillin (-7.1 kcal/mol), Ketoprofen (-7.0 kcal/mol), and Mefloquine (-7.0 kcal/mol) reported in previous articles. Based on the excellent binding affinities of these herbal compounds, we concluded that these phytochemicals could be promising candidates for fighting against the COVID-19 pandemic.

BackgroundsiRNA is a new tool for treatment of diseases such as cancer. However, it cannot be used directly due to rapid degradation in body fluid and blood stream; therefore, vectors are necessary for protection of siRNA against RNases and also for its precise delivery to the target cells. Since viral vector causes cancer and immune response in the host, liposomes are more preferable vectors. Liposome size is an important factor for longer circulation time. Extrusion minimizes the liposome size; however, it leads to less liposome encapsulation. Moreover, it changes structure of asymmetric liposomes.FindingsHere, ethanol treatment is introduced as a method of liposome size optimization that significantly decreases the liposome size without any effect on liposome encapsulation and its asymmetric structure formulation. For this, after liposome formation while there is some ether in solution, ethanol was added to fresh liposomes (25 and 30 percent of total liposomes volume) and liposomes were incubated at room temperature with mild agitation for 20 minutes. Finally, the extra ethanol and ether were removed by dialysis.ConclusionUtilizing this method the liposome size was successfully decreased about 100 nm. The size of optimized liposomes (200 nm) is quite suitable for in vivo target delivery.

Recombinant proteins have become one of the basic human needs today for pharmaceutical, industrial and research purposes. The conventional methods of producing recombinant proteins, including bacterial systems, yeast, and human cells, have led to rising prices and biosafety problems for these products. Research on commercial production of recombinant proteins prompted a new method based on plant RNA viruses and plant hosts, which is known as transient expression system. Accordingly, a viral vector based on the plant RNA virus genome was designed in which the target gene is placed underneath a viral subgenomic promoter. In these vectors, despite the genetic manipulation, the ability to infect the entire plant that was present in the virus was preserved and, several days after plant infestation, it became bioreactor for the production of recombinant protein. The advances made in this field led to the creation of hybrid vectors based on plant viruses and Agrobacterium T-DNA (Transfer DNA). The amount of recombinant protein produced by these vectors was up to 5 g/kg of fresh weight, which is considered a reliable record. The abundant benefits of this method have attracted the attention of researchers. Some of the benefits include: the rapid and high production rate, reduced production costs and the bio-safety of the manufactured products. Several recombinant drugs are currently produced by the transient expression system, either delivered to the consumer or by clinical trials. This review presents how to discover, creation and development of viral vectors in transient expression systems in order to produce recombinant proteins.

No abstract