Project description:The number of known proteins associated with plant lipid droplets (LDs) is small compared to other organelles. Many questions of LD biosynthesis and degradation remain open, also due to lack of candidate LD proteins whose characterization could help to elucidate their function in those processes. We performed a proteomic screen on LDs isolated from Nicotiana tabacum pollen tubes. Proteins that were highly enriched in the LD fraction compared to the total or cytosolic fraction where verified for LD localization via transient expression in tobacco pollen tubes. We also compared the isoforms of typical LD proteins found in the pollen tubes on a qualitative level to the isoforms found in tobacco seeds.
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. Keywords: comparative genomic hybridization, disease state analysis
Project description:Transcriptome profiling of three developmental stages of immature male gametophyte intobacco (Nicotiana tabacum) Total RNA isolated from tobacco microspores and early and late bicellular pollen was hybridised on Agilent Tobacco Gene Expression Microarray 4x44K in two biological replicates per sample
Project description:Quantitative transcriptional changes associated with chlorosis severity in mosaic leaves of tobacco plants infected with the Cucumber mosaic virus
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.