Project description:Arabidopsis thaliana is a well-established model system for the analysis of the basic physiological and metabolic pathways of plants. The presented model is a new semi-quantitative mathematical model of the metabolism of Arabidopsis thaliana. The Petri net formalism was used to express the complex reaction system in a mathematically unique manner. To verify the model for correctness and consistency concepts of network decomposition and network reduction such as transition invariants, common transition pairs, and invariant transition pairs were applied. Based on recent knowledge from literature, including the Calvin cycle, glycolysis and citric acid cycle, glyoxylate cycle, urea cycle, sucrose synthesis, and the starch metabolism, the core metabolism of Arabidopsis thaliana was formulated. Each reaction (transition) is experimentally proven. The complete Petri net model consists of 134 metabolites, represented by places, and 243 reactions, represented by transitions. Places and transitions are connected via 572 edges.
Project description:How bacteria from the microbiota modulate the physiology of its host is an important question to address. Previous work revealed that the metabolic status of Arabidopsis thaliana was crucial for the specific recruitment of Streptomycetaceae into the microbiota. Here, the Arabidopsis-Actinacidiphila interaction was further depicted by inoculating axenic Arabidopsis with Actinacidiphila cocklensis DSM 42063 or Actinacidiphila bryophytorum DSM 42138(previously named Streptomyces cocklensis and Streptomyces bryophytorum). We demonstrated that these two bacteria colonize A. thaliana wild-type plants, but their colonization efficiency was reduced in a chs5 mutant with defect in isoprenoid, phenylpropanoids and lipids synthesis. We observed that those bacteria affect the growth of the chs5 mutant but not of the wild-type plants. Using a mass spectrometry-based proteomic approach, we showed a modulation of the Arabidopsis proteome and in particular its components involved in photosynthesis or phytohormone homeostasis or perception by A. cocklensis and A. bryophytorum. This study unveils specific aspects of the Actinacidiphila-Arabidopsis interaction, which implies molecular processes impaired in the chs5 mutant and otherwise at play in the wild-type. More generally, this study highlights complex and distinct molecular interactions between Arabidopsis thaliana and bacteria belonging to the Actinacidiphila genus.
Project description:Small RNA libraries of wildtype Arabidopsis thaliana and its mutant Dicer-like 1 (Dcl1) were constructed and sequenced for miRNA identification and expression analysis. The mutant data was used to validate novel miRNA predictions (from miRCat2 (Paicu et al. 2017), miRCat (Moxon et al. 2008), miRPlant (An et al. 2014) and miReap (http://mireap.sourceforge.net/)), by calculating the log fold change between the mutant and the wildtype samples.