Unleashing the power of colloidal gold immunochromatographic assays for plant virus diagnostics.

The colloidal gold immunochromatographic assay (GICA) has become a popular method for the rapid detection of plant viruses. This assay format uses antibodies labeled with colloidal gold to capture and detect specific viral antigens in plant samples. GICA offers several advantages over traditional laboratory-based methods, including speed, ease of use, cost-effectiveness, and accessibility, making it an attractive option for plant virology diagnostics. Because plant viruses can cause significant economic losses in agriculture and horticulture, early detection is essential for effective management and control. Conventional laboratory-based methods such as enzyme-linked immunosorbent assays and polymerase chain reaction are sensitive and specific but require specialized laboratory equipment and training and can be time-consuming and costly. On the other hand, colloidal gold nanoparticles, specific antibodies and carefully designed components are integrated to allow visual detection of target viruses. This makes it an invaluable tool for plant disease management and monitoring that is simple and easy to perform and provides results within minutes. This review article aims to provide a comprehensive overview of the application of colloidal gold immunochromatographic assays for the rapid detection of plant viruses.

Molecular and biological investigating of tea plant necrotic ring blotch virus as a worldwide threat.

Tea plant necrotic ring blotch virus (TPNRBV) has emerged as a significant threat to tea plantations, primarily in China. Since 2020, similar symptoms have been observed in tea plants in northern Iran, raising concerns about the spread of this viral infection. In this study, we conducted an extensive investigation involving approximately 70 samples collected from both symptomatic and asymptomatic tea plants. Using reverse transcription-polymerase chain reaction with specially designed primers, we successfully amplified DNA fragments from 26 samples, confirming the presence of TPNRBV. Subsequent sequencing of these fragments revealed various segments of the TPNRBV genome. Our phylogenetic analysis revealed that the Iranian TPNRBV isolates formed a distinct sub-cluster alongside Chinese isolates, distinguishing them from Japanese isolates. These finding sheds light on the genetic diversity and relationships of TPNRBV across different regions. Additionally, we explored the potential modes of TPNRBV transmission. Mechanical transmission experiments confirmed the ability of the virus to infect Nicotiana rustica and Chenopodium quinoa seedlings, highlighting the risk of mechanical spread within tea plantations. Moreover, we investigated seed transmission and found evidence of TPNRBV in various parts of tea seeds, suggesting the possibility of seed-borne transmission. Overall, this comprehensive study enhances our understanding of the biological and molecular characteristics of TPNRBV, an emerging threat to global tea production. Our findings provide valuable insights into the virus's transmission dynamics and genetic diversity, which are essential for developing effective management strategies to mitigate its impact on tea cultivation worldwide.

Genome mining conformance to metabolite profile of Bacillus strains to control potato pathogens.

Biocontrol agents are safe and effective methods for controlling plant disease pathogens, such as Fusarium solani, which causes dry wilt, and Pectobacterium spp., responsible for potato soft rot disease. Discovering agents that can effectively control both fungal and bacterial pathogens in potatoes has always presented a challenge. Biological controls were investigated using 500 bacterial strains isolated from rhizospheric microbial communities, along with two promising biocontrol strains: Pseudomonas (T17-4 and VUPf5). Bacillus velezensis (Q12 and US1) and Pseudomonas chlororaphis VUPf5 exhibited the highest inhibition of fungal growth and pathogenicity in both laboratory (48%, 48%, 38%) and greenhouse (100%, 85%, 90%) settings. Q12 demonstrated better control against bacterial pathogens in vivo (approximately 50%). Whole-genome sequencing of Q12 and US1 revealed a genome size of approximately 4.1 Mb. Q12 had 4413 gene IDs and 4300 coding sequences, while US1 had 4369 gene IDs and 4255 coding sequences. Q12 exhibited a higher number of genes classified under functional subcategories related to stress response, cell wall, capsule, levansucrase synthesis, and polysaccharide metabolism. Both Q12 and US1 contained eleven secondary metabolite gene clusters as identified by the antiSMASH and RAST servers. Notably, Q12 possessed the antibacterial locillomycin and iturin A gene clusters, which were absent in US1. This genetic information suggests that Q12 may have a more pronounced control over bacterial pathogens compared to US1. Metabolic profiling of the superior strains, as determined by LC/MS/MS, validated our genetic findings. The investigated strains produced compounds such as iturin A, bacillomycin D, surfactin, fengycin, phenazine derivatives, etc. These compounds reduced spore production and caused deformation of the hyphae in F. solani. In contrast, B. velezensis UR1, which lacked the production of surfactin, fengycin, and iturin, did not affect these structures and failed to inhibit the growth of any pathogens. Our findings suggest that locillomycin and iturin A may contribute to the enhanced control of bacterial pectolytic rot by Q12.

Exploring the potential of cold plasma therapy in treating bacterial infections in veterinary medicine: opportunities and challenges.

Cold plasma therapy is a novel approach that has shown significant promise in treating bacterial infections in veterinary medicine. Cold plasma possesses the potential to eliminate various bacteria, including those that are resistant to antibiotics, which renders it a desirable substitute for traditional antibiotics. Furthermore, it can enhance the immune system and facilitate the process of wound healing. However, there are some challenges associated with the use of cold plasma in veterinary medicine, such as achieving consistent and uniform exposure to the affected area, determining optimal treatment conditions, and evaluating the long-term impact on animal health. This paper explores the potential of cold plasma therapy in veterinary medicine for managing bacterial diseases, including respiratory infections, skin infections, and wound infections such as Clostridium botulinum, Clostridium perfringens, Bacillus cereus, and Bacillus subtilis. It also shows the opportunities and challenges associated with its use. In conclusion, the paper highlights the promising potential of utilizing cold plasma in veterinary medicine. However, to gain a comprehensive understanding of its benefits and limitations, further research is required. Future studies should concentrate on refining treatment protocols and assessing the long-term effects of cold plasma therapy on bacterial infections and the overall health of animals.

Effective combination of arugula vermicompost, chitin and inhibitory bacteria for suppression of the root-knot nematode Meloidogyne javanica and explanation of their beneficial properties based on microbial analysis.

Root-knot nematodes (Meloidogyne spp.) are dangerous parasites of many crops worldwide. The threat of chemical nematicides has led to increasing interest in studying the inhibitory effects of organic amendments and bacteria on plant-parasitic nematodes, but their combination has been less studied. One laboratory and four glasshouse experiments were conducted to study the effect on M. javanica of animal manure, common vermicompost, shrimp shells, chitosan, compost and vermicompost from castor bean, chinaberry and arugula, and the combination of arugula vermicompost with some bacteria, isolated from vermicompost or earthworms. The extract of arugula compost and vermicompost, common vermicompost and composts from castor bean and chinaberry reduced nematode egg hatch by 12-32% and caused 13-40% mortality of second-stage juveniles in vitro. Soil amendments with the combination vermicompost of arugula + Pseudomonas. resinovorans + Sphingobacterium daejeonense + chitosan significantly increased the yield of infected tomato plants and reduced nematode reproduction factor by 63.1-76.6%. Comparison of chemical properties showed that arugula vermicompost had lower pH, EC, and C/N ratio than arugula compost. Metagenomics analysis showed that Bacillus, Geodermatophilus, Thermomonas, Lewinella, Pseudolabrys and Erythrobacter were the major bacterial genera in the vermicompost of arugula. Metagenomics analysis confirmed the presence of chitinolytic, detoxifying and PGPR bacteria in the vermicompost of arugula. The combination of arugula vermicompost + chitosan + P. resinovorans + S. daejeonense could be an environmentally friendly approach to control M. javanica.

A systems biology approach to pathogenesis of gastric cancer: gene network modeling and pathway analysis.

BACKGROUND: Gastric cancer (GC) ranks among the most common malignancies worldwide. This study aimed to find critical genes/pathways in GC pathogenesis. METHODS: Gene interactions were analyzed, and the protein-protein interaction network was drawn. Then enrichment analysis of the hub genes was performed and network cluster analysis and promoter analysis of the hub genes were done. Age/sex analysis was done on the identified genes. RESULTS: Eleven hub genes in GC were identified in the current study (ATP5A1, ATP5B, ATP5D, MT-ATP8, COX7A2, COX6C, ND4, ND6, NDUFS3, RPL8, and RPS16), mostly involved in mitochondrial functions. There was no report on the ATP5D, ND6, NDUFS3, RPL8, and RPS16 in GC. Our results showed that the most affected processes in GC are the metabolic processes, and the oxidative phosphorylation pathway was considerably enriched which showed the significance of mitochondria in GC pathogenesis. Most of the affected pathways in GC were also involved in neurodegenerative diseases. Promoter analysis showed that negative regulation of signal transduction might play an important role in GC pathogenesis. In the analysis of the basal expression pattern of the selected genes whose basal expression presented a change during the age, we found that a change in age may be an indicator of changes in disease insurgence and/or progression at different ages. CONCLUSIONS: These results might open up new insights into GC pathogenesis. The identified genes might be novel diagnostic/prognostic biomarkers or potential therapeutic targets for GC. This work, being based on bioinformatics analysis act as a hypothesis generator that requires further clinical validation.

Complete genome sequencing and characterization of a potential new genotype of Citrus tristeza virus in Iran.

Citrus tristeza virus (CTV) is one of the economically destructive viruses affecting citrus trees worldwide, causing significant losses in fruit production. Comparative genomic studies have shown genetic diversity in various regions of the genome of CTV isolates, which has classified the virus into several genotypes. In recent years, some orange citrumelo-tolerant rootstocks showed yellowing, decline, and vein clearing in northern Iran (Mazandaran province, Sari). We confirmed the presence of CTV in the symptomatic trees by reverse transcription PCR (RT-PCR). The complete genome of a Sari isolate of CTV (Sari isolate) was sequenced using next-generation sequencing (NGS) technology. In addition, phylogenetic analysis, differential gene expression of the virus and identification of its variants in a population were studied. We obtained the final contigs of the virus (nt) and annotated all genomes to viral ORFs, untranslated regions (UTRs), intergenic regions, and 5' and 3' ends of the genome. Phylogenetic analysis of the Sari isolate and other genotypes of CTV showed that the Sari isolates were placed in a distinct cluster without a sister group. Based on the number of specific transcripts (TPM) in CTV RNA -Seq, P13 was the most highly expressed gene related to the host range of the virus and its systemic infection. The ORFs of the polyprotein, P33, and P18 showed variation in a single population of the sari isolate. The CTV has a potential for variation in a population in a host, and these variations may contribute to the best fit of the CTV in different situations. In Iran, whole genome sequencing of the CTV was performed for the first time, and we gained new insights into CTV variation in a population.

Discovery of long non-coding RNAs in Aspergillus flavus response to water activity, CO2 concentration, and temperature changes.

Although the role of long non-coding RNAs (lncRNAs) in key biological processes in animals and plants has been confirmed for decades, their identification in fungi remains limited. In this study, we discovered and characterized lncRNAs in Aspergillus flavus in response to changes in water activity, CO2 concentration, and temperature, and predicted their regulatory roles in cellular functions. A total of 472 lncRNAs were identified in the genome of A. flavus, consisting of 470 novel lncRNAs and 2 putative lncRNAs (EFT00053849670 and EFT00053849665). Our analysis of lncRNA expression revealed significant differential expression under stress conditions in A. flavus. Our findings indicate that lncRNAs in A. flavus, particularly down-regulated lncRNAs, may play pivotal regulatory roles in aflatoxin biosynthesis, respiratory activities, cellular survival, and metabolic maintenance under stress conditions. Additionally, we predicted that sense lncRNAs down-regulated by a temperature of 30 °C, osmotic stress, and CO2 concentration might indirectly regulate proline metabolism. Furthermore, subcellular localization analysis revealed that up-and down-regulated lncRNAs are frequently localized in the nucleus under stress conditions, particularly at a water activity of 0.91, while most up-regulated lncRNAs may be located in the cytoplasm under high CO2 concentration.

Gene network modeling and pathway analysis of maize transcriptomes in response to Maize Iranian mosaic virus.

Maize Iranian mosaic virus (MIMV, family Rhabdoviridae) is one of the factors limiting cereal production in Iran. In the present study, we sought to find critical genes and key pathways involved in MIMV infection and analyzed gene networks, pathways and promoters using transcriptome data. We determined the hub genes involved in pathways related to the proteasome and ubiquitin. The results showed the important role of the cellular endoplasmic reticulum in MIMV infection. Network cluster analysis confirmed the result of GO and Kyoto Encyclopedia of Genes and Genomes (KEGG) analysis. The discovered miRNAs belonged to miR166, miR167, miR169, miR395, miR399, miR408 and miR482 families, which are involved in various pathogenicity or resistance processes against MIMV or other viruses. The results of this study provide a list of hub genes, important pathways and new insights for the future development of virus-resistant transgenic crops and clarify the basic mechanism of plant response.

Gene Networks Analysis of Salmonella Typhimurium Reveals New Insights on Key Genes Involved in Response to Low Water Activity.

Background: When Salmonella enterica serovar Typhimurium, a foodborne bacterium, is exposed to osmotic stress, cellular adaptations increase virulence severity and cellular survival. Objectives: The aim of the gene network analysis of S. Typhimurium was to provide insights into the various interactions between the genes involved in cellular survival under low water activity (aw). Materials and Methods: We performed a gene network analysis to identify the gene clusters and hub genes of S. Typhimurium using Cytoscape in three food samples subjected to aw stress after 72 hours. Results: The identified hub genes of S. Typhimurium belonged to down-regulated genes and were related to translation, transcription, and ribosome structure in the food samples. The rpsB and Tig were identified as the most important of the hub genes. Enrichment analysis of the hub genes also revealed the importance of translation and cellular protein metabolic processes. Moreover, the biological process associated with organonitrogen metabolism in milk chocolate was identified. According to the KEGG pathway results of gene cluster analysis, cellular responses to stress were associated with RNA polymerase, ribosome, and oxidative phosphorylation. Genes encoding RNA polymerase activity, including rpoA, rpoB, and rpoZ, were also significantly identified in the KEGG pathways. The identified motifs of hub DEGs included EXPREG_00000850, EXPREG_00000b00, EXPREG_000008e0, and EXPREG_00000850. Conclusion: Based on the results of the gene network analysis, the identified hub genes may contribute to adaptation to food compositions and be responsible for the development of low water stress tolerance in Salmonella. Among the food samples, the milk chocolate matrix leads to more adaptation pathways for S. Typhimurium survival, as more hub genes were down-regulated and more motifs were detected. The identified motifs were involved in carbohydrate metabolism, carbohydrate transport, electron transfer, and oxygen transfer.

Regulatory non-coding RNA: The core defense mechanism against plant pathogens.

Plant pathogens damage crops and threaten global food security. Plants have evolved complex defense networks against pathogens, using crosstalk among various signaling pathways. Key regulators conferring plant immunity through signaling pathways include protein-coding genes and non-coding RNAs (ncRNAs). The discovery of ncRNAs in plant transcriptomes was first considered "transcriptional noise". Recent reviews have highlighted the importance of non-coding RNAs. However, understanding interactions among different types of noncoding RNAs requires additional research. This review attempts to consider how long-ncRNAs, small-ncRNAs and circular RNAs interact in response to pathogenic diseases within different plant species. Developments within genomics and bioinformatics could lead to the further discovery of plant ncRNAs, knowledge of their biological roles, as well as an understanding of their importance in exploiting the recent molecular-based technologies for crop protection.

Effects of Arugula Vermicompost on the Root-Knot Nematode (Meloidogyne javanica) and the Promotion of Resistance Genes in Tomato Plants.

Root-knot nematodes are the most important plantparasitic nematodes worldwide. Many efforts have been made to find non-chemical, risk-free, and environmentally friendly methods for nematode control. In this study, the effects of compost and vermicompost of arugula (Eruca sativa) on Meloidogyne javanica were investigated in three glasshouse experiments. In addition, the expression of the defense-related genes nonexpressor of pathogenesis-related 1 (NPR1) and lipoxygenase 1 (LOX1) was detected in tomato plants treated with vermicompost of arugula at 0, 2, 7, and 14 days after nematode inoculation. The result showed that the vermicompost of arugula significantly reduced the reproduction factor of the nematode by 54.4% to 70.5% in the three experiments and increased the dry weight of shoots of infected tomato plants. Gene expression analysis showed that LOX1 expression increased on the second and seventh day after nematode inoculation, while NPR1 expression decreased. The vermicompost of arugula showed stronger nematode inhibitory potential than the vermicompost of animal manure. The vermicompost of arugula is superior to arugula compost in suppressing the activity of M. javaniva and reducing its impact. It manipulates the expression of resistance genes and could induce systemic resistance against rootknot nematodes.

Network for network concept offers new insights into host- SARS-CoV-2 protein interactions and potential novel targets for developing antiviral drugs.

SARS-CoV-2, the causal agent of COVID-19, is primarily a pulmonary virus that can directly or indirectly infect several organs. Despite many studies carried out during the current COVID-19 pandemic, some pathological features of SARS-CoV-2 have remained unclear. It has been recently attempted to address the current knowledge gaps on the viral pathogenicity and pathological mechanisms via cellular-level tropism of SARS-CoV-2 using human proteomics, visualization of virus-host protein-protein interactions (PPIs), and enrichment analysis of experimental results. The synergistic use of models and methods that rely on graph theory has enabled the visualization and analysis of the molecular context of virus/host PPIs. We review current knowledge on the SARS-COV-2/host interactome cascade involved in the viral pathogenicity through the graph theory concept and highlight the hub proteins in the intra-viral network that create a subnet with a small number of host central proteins, leading to cell disintegration and infectivity. Then we discuss the putative principle of the "gene-for-gene and "network for network" concepts as platforms for future directions toward designing efficient anti-viral therapies.

Highlight of potential impact of new viral genotypes of SARS-CoV-2 on vaccines and anti-viral therapeutics.

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), the causal agent of the coronavirus disease (COVID-19) pandemic, has infected millions of people globally. Genetic variation and selective pressures lead to the accumulation of single nucleotide polymorphism (SNP) within the viral genome that may affect virulence, transmission rate, viral recognition and the efficacy of prophylactic and interventional measures. To address these concerns at the genomic level, we assessed the phylogeny and SNPs of the SARS-CoV-2 mutant population collected to date in Iran in relation to globally reported variants. Phylogenetic analysis of mutant strains revealed the occurrence of the variants known as B.1.1.7 (Alpha), B.1.525 (Eta), and B.1.617 (Delta) that appear to have delineated independently in Iran. SNP analysis of the Iranian sequences revealed that the mutations were predominantly positioned within the S protein-coding region, with most SNPs localizing to the S1 subunit. Seventeen S1-localizing SNPs occurred in the RNA binding domain that interacts with ACE2 of the host cell. Importantly, many of these SNPs are predicted to influence the binding of antibodies and anti-viral therapeutics, indicating that the adaptive host response appears to be imposing a selective pressure that is driving the evolution of the virus in this closed population through enhancing virulence. The SNPs detected within these mutant cohorts are addressed with respect to current prophylactic measures and therapeutic interventions.

Characterization of maize miRNAs responsive to maize Iranian mosaic virus infection.

MicroRNAs (miRNAs) play key regulatory roles in the plant's response to biotic and abiotic stresses and have fundamental functions in plant-virus interactions. The study of changes in miRNAs in response to virus infection can provide molecular details for a better understanding of virus-host interactions. Maize Iranian mosaic virus (MIMV) infects maize and certain other poaceous plants but miRNA changes in response to MIMV infection are unknown. In the present study, we compared the miRNA profiles of MIMV-infected and uninfected maize and characterized their predicted roles in response to the virus. Small RNA sequencing of maize identified 257 conserved miRNAs of 26 conserved families in uninfected and MIMV-infected maize libraries. Among them, miR395, miR166 and miR156 family members were highly represented. Small RNA data were confirmed using RT-qPCR. In addition, 33 potential novel miRNAs were predicted. The data show that 13 miRNAs were up-regulated and 113 were down-regulated in response to MIMV infection. Several of those miRNAs are known to be important in the response to plant pathogens. To determine the potential roles of individual miRNAs in response to MIMV, miRNA targets, predicted interactions with circular RNAs and comparative transcriptome data were analyzed. The expression profiles of different miRNAs in response to MIMV provide novel insights into the roles of miRNAs in the interaction between MIMV and maize plants. SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1007/s13205-022-03134-1.

Comparative phylogenetic analysis of SARS-CoV-2 spike protein-possibility effect on virus spillover.

Coronavirus disease 2019 has developed into a dramatic pandemic with tremendous global impact. The receptor-binding motif (RBM) region of the causative virus, severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), binds to host angiotensin-converting enzyme 2 (ACE2) receptors for infection. As ACE2 receptors are highly conserved within vertebrate species, SARS-CoV-2 can infect significant animal species as well as human populations. An analysis of SARS-CoV-2 genotypes isolated from human and significant animal species was conducted to compare and identify mutation and adaptation patterns across different animal species. The phylogenetic data revealed seven distinct phylogenetic clades with no significant relationship between the clades and geographical locations. A high rate of variation within SARS-CoV-2 mink isolates implies that mink populations were infected before human populations. Positions of most single-nucleotide polymorphisms (SNPs) within the spike (S) protein of SARS-CoV-2 genotypes from the different hosts are mostly accumulated in the RBM region and highlight the pronounced accumulation of variants with mutations in the RBM region in comparison with other variants. These SNPs play a crucial role in viral transmission and pathogenicity and are keys in identifying other animal species as potential intermediate hosts of SARS-CoV-2. The possible roles in the emergence of new viral strains and the possible implications of these changes, in compromising vaccine effectiveness, deserve urgent considerations.

A short overview of CRISPR-Cas technology and its application in viral disease control.

Clustered Regularly Interspaced Short Palindromic Repeats (CRISPRs) together with CRISPR-associated (Cas) proteins have catalysed a revolution in genetic engineering. Native CRISPR-Cas systems exist in many bacteria and archaea where they provide an adaptive immune response through sequence-specific degradation of an invading pathogen's genome. This system has been reconfigured for use in genome editing, drug development, gene expression regulation, diagnostics, the prevention and treatment of cancers, and the treatment of genetic and infectious diseases. In recent years, CRISPR-Cas systems have been used in the diagnosis and control of viral diseases, for example, CRISPR-Cas12/13 coupled with new amplification techniques to improve the specificity of sequence-specific fluorescent probe detection. Importantly, CRISPR applications are both sensitive and specific and usually only require commonly available lab equipment. Unlike the canonical Cas9 which is guided to double-stranded DNA sites of interest, Cas13 systems target RNA sequences and thus can be employed in strategies directed against RNA viruses or for transcriptional silencing. Many challenges remain for these approach, including issues with specificity and the requirement for better mammalian delivery systems. In this review, we summarize the applications of CRISPR-Cas systems in controlling mammalian viral infections. Following necessary improvements, it is expected that CRISPR-Cas systems will be used effectively for such applications in the future.

Hepatitis B core-based virus-like particles: A platform for vaccine development in plants.

Virus-like particles (VLPs) are a class of structures formed by the self-assembly of viral capsid protein subunits and contain no infective viral genetic material. The Hepatitis B core (HBc) antigen is capable of assembling into VLPs that can elicit strong immune responses and has been licensed as a commercial vaccine against Hepatitis B. The HBc VLPs have also been employed as a platform for the presentation of foreign epitopes to the immune system and have been used to develop vaccines against, for example, influenza A and Foot-and-mouth disease. Plant expression systems are rapid, scalable and safe, and are capable of providing correct post-translational modifications and reducing upstream production costs. The production of HBc-based virus-like particles in plants would thus greatly increase the efficiency of vaccine production. This review investigates the application of plant-based HBc VLP as a platform for vaccine production.

Quasi-species nature and differential gene expression of severe acute respiratory syndrome coronavirus 2 and phylogenetic analysis of a novel Iranian strain.

A novel coronavirus related to severe acute respiratory syndrome virus, (SARS-CoV-2) is the causal agent of the COVID-19 pandemic. Despite the genetic mutations across the SARS-CoV-2 genome being recently investigated, its transcriptomic genetic polymorphisms at inter-host level and the viral gene expression level based on each Open Reading Frame (ORF) remains unclear. Using available High Throughput Sequencing (HTS) data and based on SARS-CoV-2 infected human transcriptomic data, this study presents a high-resolution map of SARS-CoV-2 single nucleotide polymorphism (SNP) hotspots in a viral population at inter-host level. Four throat swab samples from COVID-19 infected patients were pooled, with RNA-Seq read retrieved from SRA NCBI to detect 21 SNPs and a replacement across the SARS-CoV-2 genomic population. Twenty-two RNA modification sites on viral transcripts were identified that may cause inter-host genetic diversity of this virus. In addition, the canonical genomic RNAs of N ORF showed higher expression in transcriptomic data and reverse transcriptase quantitative PCR compared to other SARS-CoV-2 ORFs, indicating the importance of this ORF in virus replication or other major functions in virus cycle. Phylogenetic and ancestral sequence analyses based on the entire genome revealed that SARS-CoV-2 is possibly derived from a recombination event between SARS-CoV and Bat SARS-like CoV. Ancestor analysis of the isolates from different locations including Iran suggest shared Chinese ancestry. These results propose the importance of potential inter-host level genetic variations to the evolution of SARS-COV-2, and the formation of viral quasi-species. The RNA modifications discovered in this study may cause amino acid sequence changes in polyprotein, spike protein, product of ORF8 and nucleocapsid (N) protein, suggesting further insights to understanding the functional impacts of mutations in the life cycle and pathogenicity of SARS-CoV-2.

Detection and profiling of circular RNAs in uninfected and maize Iranian mosaic virus-infected maize.

Circular RNAs (circRNAs) are covalently closed non-coding RNAs that are usually derived from exonic regions of genes, but can also arise from intronic and intergenic regions. Studies of circRNAs in humans, animals and several plant species have shown an altered population of circRNAs in response to abiotic and biotic stress. Recently it was shown that circRNAs also occur in maize, but it is unknown if maize circRNAs are responsive to stress. Maize Iranian mosaic virus (MIMV, genus Nucleorhabdovirus, family Rhabdoviridae) causes an economically important disease in maize and other gramineous crops in Iran. In this study, we used data from RNA-Seq of MIMV-infected maize and uninfected controls to identify differentially expressed circRNAs. Such circRNAs were confirmed by two-dimensional polyacrylamide gel electrophoresis, northern blot, RT-qPCR and sequencing. A total of 1443 circRNAs were identified in MIMV-infected maize and 1165 circRNAs in uninfected maize. Two hundred and one circRNAs were in common between MIMV-infected and uninfected samples. Of these, 155 circRNAs were up-regulated and 5 down-regulated in MIMV infected plants, compared to the uninfected control. This study for the first time identified and profiled circRNA expression in maize in response to virus infection. Moreover, we predict that 33 circRNAs may bind 23 maize miRNAs, possibly affecting plant metabolism and development. Our data suggest a role for circRNAs in plant cell regulation and response to biotic stress such as virus infection, and give new insights into the complexity of plant-microbe interactions.