Project description:Transgenic expression of viral proteins in natural host plants is a useful simplified system with the potential to understand the individual effect of each viral component. Transgenic expression of movement (MP) and a variant from coat protein (CPT42W) in tobacco, a TMV natural host, produces severe morphological changes, altered miRNAs accumulation and poor fertility. We used microarrays to characterize the gene expression changes caused by the co-expression of TMV capsid and movement proteins in Nicotiana tabacum comparing two isogenic lines MPxCPT42W and mpxcpT42W* (a line with both transgenes spontaneously silenced and with normal phenotype).
Project description:Transgenic expression of viral proteins in natural host plants is a useful simplified system with the potential to understand the individual effect of each viral component. Transgenic expression of movement (MP) and a variant from coat protein (CPT42W) in tobacco, a TMV natural host, produces severe morphological changes, altered miRNAs accumulation and poor fertility. We used microarrays to characterize the gene expression changes caused by the co-expression of TMV capsid and movement proteins in Nicotiana tabacum comparing two isogenic lines MPxCPT42W and mpxcpT42W* (a line with both transgenes spontaneously silenced and with normal phenotype). Leaf tissues from 6-week old tobacco plants MPxCPT42W and mpxcpT42W* were collected for RNA extraction and hybridization on Affymetrix microarrays. We collected pools of three plants (one biological replicate) and analyzed three independent biological replicates for each transgenic line.
Project description:Strigolactones (SLs) are plant hormones that regulate diverse developmental processes and environmental responses in plants. It has been discovered that SLs play an important role in regulating plant immune resistance to pathogens, but there are currently no reports on their role in the interaction between Nicotiana benthamiana and Tobacco mosaic virus (TMV). In this study, the exogenous application of SLs weakened the resistance of N. benthamiana to TMV, promoting TMV infection, whereas the exogenous application of Tis108, an SL inhibitor, resulted in the opposite effect. Virus-induced gene silencing (VIGS) inhibition of two key SL synthesis enzyme genes, NtCCD7 and NtCCD8, enhanced the resistance of N. benthamiana to TMV. Additionally, we conducted a screening of N. benthamiana related to TMV infection. TMV-infected plants treated with SLs were compared to the control by using RNA-seq. KEGG enrichment analysis and weighted gene co-expression network analysis (WGCNA) of differentially expressed genes (DEGs) suggested that plant hormone signaling transduction may play a significant role in the SL-TMV-N. benthamiana interactions. This study reveals new functions of SLs in regulating plant immunity and provides a reference for controlling TMV diseases in production.
Project description:In this study we used vascular specific promoters and a translating ribosome affinity purification strategy to identify phloem-associated translatome responses to infection by tobacco mosaic virus (TMV) in the systemic host Nicotiana benthamiana. Three different promoter:FLAG-RPL18 lines were used. These included two phloem specific promoters (pSUC2 and pSULTR2;2) as well as the more ubiquitously expressed cauliflower mosaic virus 35S promoter (p35S). Immunopurification of ribosome-mRNA complexes was accomplished by the method described in Reynoso et al. (Plant Functional Genomics: Methods and Protocols, 185-207; 2015). The dataset includes samples from the leaves of 5-week-old plants inoculated with TMV (1 mg/mL) or mock inoculated with sterile water.
Project description:Transcriptome analysis in tobacco mutant plants using tomato Genechip Genome array Tobacco (Nicotiana tabacum cv. Petit Havanna) psaA and psbA deletion mutants were constructed through a targeted deletion of 767 and 1152 nucleotides of coding regions, respectively with two gene cassettes: psbAproR:uidA:psbterR and rrnR:aadA:rbcLterR coding for GUS reporter and spectinomycin selectable marker genes, respectively. Standard established procedures were followed for chloroplast transformation to generate the psaA and psbA deletion mutants based on the homologous recombination. Gene expression profiles in psaA and psbA tobacco mutant plants were analyzed using tomato Genechip Genome array to study the global changes in the expression of genome.
Project description:Although Pseudomonas aeruginosa is an opportunistic pathogen that does not often naturally infect alternate hosts such as plants, the plant-P. aeruginosa model has become a widely recognized system for identifying new virulence determinants and studying pathogenesis of this organism. Here we examine how both host factors and P. aeruginosa PAO1 gene expression are affected in planta after infiltration into incompatible and compatible cultivars of tobacco (Nicotiana tabacum L.) Nicotiana tabacum has a resistance gene (N) against tobacco mosaic virus; and although resistance to PAO1 infection correlated to the presence of a dominant N-gene, our data suggests that it is not a factor in resistance against Pseudomonas. We did observe that the resistant tobacco cultivar had higher basal levels of salicylic acid, and a stronger salicylic acid response upon infiltration of PAO1. Salicylic acid acts as a signal to activate defense responses in plants, limiting the spread of the pathogen and preventng access to nutrients. It has also been shown to have direct virulence modulating effects on P. aeruginosa. We also examined host effects on the pathogen by analyzing global gene expression profiles of bacteria removed from the intracellular fluid of the two plant hosts. We discovered that the availability of micronutrients, particularly sulfate and Pi, are important factors in in planta pathogenesis, and that the amounts of these nutrients made available to the bacteria may in turn have an effect on virulence gene expression. Indeed, there are several reports suggesting that P. aeruginosa virulence is influenced in mammalian hosts by the availability of iron and by levels of O2. Experiment Overall Design: Pseudomonas aeruginosa cells were removed from leaf tissue 24 hours post-infiltration and RNA was directly extracted from these cells. Comparisons are between cells removed from a susceptible cultivar of Nicotiana tabacum (cv. Samsun) and a resistant cultivar (cv. Xanthi). Three biological replicates per cultivar were analyzed.
Project description:Transcriptome analysis in tobacco mutant plants using tomato Genechip Genome array Tobacco (Nicotiana tabacum cv. Petit Havanna) psaA and psbA deletion mutants were constructed through a targeted deletion of 767 and 1152 nucleotides of coding regions, respectively with two gene cassettes: psbAproR:uidA:psbterR and rrnR:aadA:rbcLterR coding for GUS reporter and spectinomycin selectable marker genes, respectively. Standard established procedures were followed for chloroplast transformation to generate the psaA and psbA deletion mutants based on the homologous recombination. Gene expression profiles in psaA and psbA tobacco mutant plants were analyzed using tomato Genechip Genome array to study the global changes in the expression of genome. Total RNA was isolated from psaA and psbA tobacco mutant plants along with the wild type plants. Biotin labeled cRNA was hybridized on tomato GeneChip Genome Array following the Affymetrix protocols. Two independent biological replicates were maintained.
Project description:In this study we used vascular specific promoters and a translating ribosome affinity purification strategy to identify phloem-associated translatome responses to infection by tobacco mosaic virus (TMV) in the systemic host Arabidopsis thaliana ecotype Shahdara. Three different promoter:FLAG-RPL18 lines were used. These included two phloem specific promoters (pSUC2 and pSULTR2;2) as well as the more ubiquitously expressed cauliflower mosaic virus 35S promoter (p35S). Immunopurification of ribosome-mRNA complexes was accomplished by the method described in Reynoso et al. (Plant Functional Genomics: Methods and Protocols, 185-207; 2015). The dataset includes samples from the leaves of 5-week-old plants inoculated with TMV (1 mg/mL) or mock inoculated with sterile water.
Project description:The early events of virus infection is one of the more poorly understood areas of plant virology and studies on the effect of virus on the host proteome at very early stages of infection are lacking. In the present study, we analysed the proteome on the early stage changes at 15 minutes post inoculation in the tobacco-TMV pathosystem with and without exogenous application of dsRNA p126