Project description:Hypersensitive response-related programmed cell death (PCD) has been extensively analyzed in various plant–virus interactions. However, little is known about changes in gene expression associated with cell death caused by compatible viruses. The synergistic interaction of Potato virus X (PVX) with Plum pox virus (PPV) results in increased symptoms that lead to systemic necrosis (SN) in Nicotiana benthamiana. Here, we performed three transcriptome comparisons in response to i) a PVX recombinant virus expressing the helper component-proteinase (HC-Pro) gene from PPV that leads to SN, ii) a systemic incompatible interaction conferred by the Tobacco mosaic virus (TMV)-resistance gene N (SHR), and iii) the depletion of the PBE subunit of the proteasome that leads to PCD by virus induced gene silencing (VIGS Prot), at early and late stages of infection. Our analysis indicated that the SN response was clustered with SHR by the similarity of their overall gene expression profiles. However, the expression profiles of defence-related and hormone-responsive genes in response to SN were more closely related to the response to VIGS Prot than to that elicited by SHR. This suggests the potential contribution of proteasome dysfunction to the increase in pathogenicity observed in PVX-potyvirus infections
Project description:The changes of small RNA profile have been studied in tomato and wild tomato plants to understand the host reponse to the infection of a non-coding viral RNA infection.
Project description:Hypersensitive response-related programmed cell death (PCD) has been extensively analyzed in various plant–virus interactions. However, little is known about changes in gene expression associated with cell death caused by compatible viruses. The synergistic interaction of Potato virus X (PVX) with Plum pox virus (PPV) results in increased symptoms that lead to systemic necrosis (SN) in Nicotiana benthamiana. Here, we performed three transcriptome comparisons in response to i) a PVX recombinant virus expressing the helper component-proteinase (HC-Pro) gene from PPV that leads to SN, ii) a systemic incompatible interaction conferred by the Tobacco mosaic virus (TMV)-resistance gene N (SHR), and iii) the depletion of the PBE subunit of the proteasome that leads to PCD by virus induced gene silencing (VIGS Prot), at early and late stages of infection. Our analysis indicated that the SN response was clustered with SHR by the similarity of their overall gene expression profiles. However, the expression profiles of defence-related and hormone-responsive genes in response to SN were more closely related to the response to VIGS Prot than to that elicited by SHR. This suggests the potential contribution of proteasome dysfunction to the increase in pathogenicity observed in PVX-potyvirus infections We compare the gene expression profiles of Nicotiana benthamiana plants infected with either necrosis-inducing viruses or non-necrosis-inducing viruses, as follow: PVX/HCWT-infected plants versus plants infected with a PVX recombinant virus expressing a PPV HC-Pro mutant (PVX/HCLH) that was unable to induce the SN response (SN comparison), at 7 and 11 days postinoculation (dpi), (ii) TRV:NbPBE-silenced plants versus plants infected with the TRV empty vector (VIGS Prot comparison), at 4 and 8 days after infiltration (dpa), and (iii) TMV-GFP-infected, N-transgenic plants versus wild-type plants infected with TMV-GFP (SHR comparison), at 24 and 72 hours after temperature shift (hts). Per time and treatment, three independent biological replicates were used to monitor differences in gene expression between treatments
Project description:70mer probes were designed to detect plant viruses infection in genus level. This microarray platform is able to detect 169 plant virus species of 13 virus genera.
Project description:Many virus diseases of economic importance to agriculture result from mixtures of different pathogens invading the host at a given time. This contrasts with the relatively scarce studies available on the molecular events associated with virus-host interactions in mixed infections. In comparison to single infections, co-infection of Nicotiana benthamiana with Potato virus X (PVX) and Potato virus Y (PVY) resulted in increased systemic symptoms (synergism) that led to necrosis of the newly emerging leaves, and the plant death. A comparative transcriptional analysis was undertaken to identify quantitative and qualitative differences in gene expression during this synergistic infection, and to correlate these changes with the severe symptoms it caused. Global transcription profiles of doubly-infected leaves were compared with those from singly-infected leaves using gene ontology enrichment analysis and metabolic pathway annotator software. Functional gene categories altered by the double infection comprise suites of genes regulated coordinately, which are associated with chloroplast functions (down-regulated), protein synthesis and degradation (up-regulated), carbohydrate metabolism (up-regulated), and response to biotic stimulus and stress (up-regulated). The expression of reactive oxygen species-generating enzymes as well as several mitogen-activated protein kinases, were also significantly induced. Accordingly, synergistic infection induced a severe oxidative stress in N. benthamiana leaves, as judged by increases in lipid peroxidation, and by the generation of superoxide radicals in chloroplasts, which correlated with the misregulation of antioxidative genes in microarray data. Interestingly, expression of genes encoding oxylipin biosynthesis was uniquely up-regulated by the synergistic infection. Virus-induced gene silencing of alfa-dioxygenase1 delayed cell death during PVX-PVY infection. Using mock inoculated leaf tissue as a reference, we compare the gene expression profiles of Nicotiana benthamiana plants infected with one of two viruses, Potato virus X (PVX) or Potato virus Y (PVY), or the combination PVX plus PVY. 3 biological replicates per treatment were independently grown and haversted.
Project description:West Nile virus (WNV) causes an acute neurological infection attended by massive neuronal cell death. However, the mechanism(s) behind the virus-induced cell death is poorly understood. Using a library containing 77,406 sgRNAs targeting 20,121 genes, we performed a genome-wide screen using CRISPR/Cas9. HEK 293FT cells were infected with lentivirus expressing sgRNAs and then transfected with a Cas9 expressing construct. WNV infection killed most cells during a 12d selection. Survivor cells were harvested, from which DNA was isolated. The sgRNAs integrated in genome of survivor cells were amplified with PCR. The PCR product was sequenced with Illumina MiSeq to profile the sgRNA population in the survivor cells. Three replicates were conducted. Similarly, a second round of screen was conducted. Among the genes identified, seven genes, EMC2, EMC3, SEL1L, DERL2, UBE2G2, UBE2J2, and HRD1, stood out as having the strongest phenotype, whose knockout conferred strong protection against WNV-induced cell death with two different WNV strains and in three cell lines. Interestingly, knockout of these genes did not block WNV replication. Thus, these appear to be essential genes that link WNV replication to downstream cell death pathway(s). In addition, the fact that all of these genes belong to the endoplasmic reticulum-associated protein degradation (ERAD) pathway suggests that this might be the primary driver of WNV-induced cell death. Examination of sgRNA populations in survival 293FT cells
Project description:70mer probes were designed to detect plant viruses infection in genus level. This microarray platform is able to detect 169 plant virus species of 13 virus genera. Virus sampels were extracted from infected plant hosts. Genomic RNA was extracted and hybridized to the microarray.
Project description:Many virus diseases of economic importance to agriculture result from mixtures of different pathogens invading the host at a given time. This contrasts with the relatively scarce studies available on the molecular events associated with virus-host interactions in mixed infections. In comparison to single infections, co-infection of Nicotiana benthamiana with Potato virus X (PVX) and Potato virus Y (PVY) resulted in increased systemic symptoms (synergism) that led to necrosis of the newly emerging leaves, and the plant death. A comparative transcriptional analysis was undertaken to identify quantitative and qualitative differences in gene expression during this synergistic infection, and to correlate these changes with the severe symptoms it caused. Global transcription profiles of doubly-infected leaves were compared with those from singly-infected leaves using gene ontology enrichment analysis and metabolic pathway annotator software. Functional gene categories altered by the double infection comprise suites of genes regulated coordinately, which are associated with chloroplast functions (down-regulated), protein synthesis and degradation (up-regulated), carbohydrate metabolism (up-regulated), and response to biotic stimulus and stress (up-regulated). The expression of reactive oxygen species-generating enzymes as well as several mitogen-activated protein kinases, were also significantly induced. Accordingly, synergistic infection induced a severe oxidative stress in N. benthamiana leaves, as judged by increases in lipid peroxidation, and by the generation of superoxide radicals in chloroplasts, which correlated with the misregulation of antioxidative genes in microarray data. Interestingly, expression of genes encoding oxylipin biosynthesis was uniquely up-regulated by the synergistic infection. Virus-induced gene silencing of alfa-dioxygenase1 delayed cell death during PVX-PVY infection.
Project description:West Nile virus (WNV) causes an acute neurological infection attended by massive neuronal cell death. However, the mechanism(s) behind the virus-induced cell death is poorly understood. Using a library containing 77,406 sgRNAs targeting 20,121 genes, we performed a genome-wide screen using CRISPR/Cas9. HEK 293FT cells were infected with lentivirus expressing sgRNAs and then transfected with a Cas9 expressing construct. WNV infection killed most cells during a 12d selection. Survivor cells were harvested, from which DNA was isolated. The sgRNAs integrated in genome of survivor cells were amplified with PCR. The PCR product was sequenced with Illumina MiSeq to profile the sgRNA population in the survivor cells. Three replicates were conducted. Similarly, a second round of screen was conducted. Among the genes identified, seven genes, EMC2, EMC3, SEL1L, DERL2, UBE2G2, UBE2J2, and HRD1, stood out as having the strongest phenotype, whose knockout conferred strong protection against WNV-induced cell death with two different WNV strains and in three cell lines. Interestingly, knockout of these genes did not block WNV replication. Thus, these appear to be essential genes that link WNV replication to downstream cell death pathway(s). In addition, the fact that all of these genes belong to the endoplasmic reticulum-associated protein degradation (ERAD) pathway suggests that this might be the primary driver of WNV-induced cell death.
Project description:Plant viruses rely on both host plant and vectors for a successful infection. This study investigated the global transcriptomic changes in Arabidopsis thaliana that were simultaneously exposed to both a plant virus (turnip yellows virus, polerovirus genus and Solemoviridae family) and its aphid vector (Myzus persicae). Some of these modifications in gene expression may promote in a timely manner viral transmission and dispersion.