ABSTRACT
Biosynthesis of antimicrobial secondary metabolites in response to microbial infection is one of the features of the plant immune system. Particular classes of plant secondary metabolites involved in plant defence are often produced only by species belonging to certain phylogenetic clades. Brassicaceae plants have evolved the ability to synthesise a wide range of sulfur-containing secondary metabolites, including glucosinolates and indole-type phytoalexins. A subset of these compounds is produced by the model plant Arabidopsis thaliana. Genetic tools available for this species enabled verification of immune functions of glucosinolates and camalexin (A. thaliana phytoalexin), as well as characterisation of their respective biosynthetic pathways. Current knowledge of the biosynthesis of Brassicaceae sulfur-containing metabolites suggests that the key event in the evolution of these compounds is the acquisition of biochemical mechanisms originating from detoxification pathways into secondary metabolite biosynthesis. Moreover, it is likely that glucosinolates and Brassicaceae phytoalexins, traditionally considered as separate groups of compounds, have a common evolutionary origin and are interconnected on the biosynthetic level. This suggests that the diversity of Brassicaceae sulfur-containing phytochemicals reflect phylogenetic clade-specific branches of an ancient biosynthetic pathway.
Subject(s)
Brassicaceae/immunology , Glucosinolates/immunology , Plant Immunity , Sesquiterpenes/immunology , Sulfur Compounds/immunology , Arabidopsis/chemistry , Arabidopsis/immunology , Arabidopsis/metabolism , Brassicaceae/chemistry , Brassicaceae/metabolism , Glucosinolates/chemistry , Glucosinolates/metabolism , Sesquiterpenes/chemistry , Sesquiterpenes/metabolism , Sulfur Compounds/chemistry , Sulfur Compounds/metabolism , PhytoalexinsSubject(s)
Antibody Specificity , Antigens, Bacterial/immunology , Antigens, Neoplasm/immunology , Oligosaccharides/immunology , Sulfur Compounds/immunology , Vaccines, Conjugate/immunology , Antigens, Bacterial/chemistry , Antigens, Fungal/chemistry , Antigens, Fungal/immunology , Antigens, Neoplasm/chemistry , Carbohydrate Sequence , Molecular Sequence Data , Oligosaccharides/chemistry , Sulfur Compounds/chemistry , Vaccines, Conjugate/chemistryABSTRACT
Sulphopolysaccharides, isolated from gastric juice of patients with pernicious anemia or gastric cancer, have been characterized immunologically using corresponding rabbit immunosera. Gastric juice sulphopolysaccharides differ from their normal form in the following conditions: a) when there is intestinal type metaplastic tissue in the gastric epithelium; b) in the presence of gastric cancer. Efforts to differentiate between these types by the absorption technique using rabbit immunosera were successful, and it was possible to demonstrate an antigenic determinant in sulphopolysaccharides from cancerous gastric juice not present in controls with benign intestinal type heterotopia as in pernicious anemia.
