title: Physiological and genetic analysis of Arabidopsis thaliana anthocyanin biosynthesis mutants under chronic adverse environmental conditions.
abstract: Anthocyanin production is a characteristic response of flowering plants to unfavourable environmental conditions. The potential roles of flavonoids and anthocyanins in plant growth were investigated by growing Arabidopsis thaliana anthocyanin production mutants (transparent testa) under limiting nitrogen and high light conditions. Inability to produce kaempferol or subsequent intermediate compounds by some transparent testa lines was correlated with less biomass accumulation in mature plants compared with wild-type control plants under all growth conditions tested. However, under both limiting nitrogen and high light chronic stress conditions, mutant lines defective in later steps of the anthocyanin production pathway produced the same or more biomass than wild-type plants. No difference in senescence between transparent testa and wild-type plants was found using chlorophyll catabolism and SAG12 expression measurements, and no mutants were impaired in the ability to remobilize nutrients from the vegetative to reproductive tissues. Moreover, the absence of anthocyanin and/or upstream flavonoids does not affect the ability of plants to respond to limiting nitrogen by reducing photosynthetic capacity. These results support a role for kaempferol and quercetin accumulation in normal plant growth and development. Further, the absence of anthocyanins has no effect on plant growth under the chronic stress conditions tested.
authors.affiliation: Department of Molecular and Cellular Biology,  University of Guelph, 50 Stone rd. E, Guelph, ON N1G 2W1,  Canada.
authors.forename: Maksym
authors.initials: M
authors.lastname: Misyura
authors.forename: Joseph
authors.initials: J
authors.lastname: Colasanti
authors.forename: Steven J
authors.initials: SJ
authors.lastname: Rothstein
mesh_terms: D000872:Anthocyanins / Q000096:biosynthesis*; D017360:Arabidopsis / Q000187:drug effects / Q000235:genetics* / Q000254:growth & development / Q000502:physiology*; D029681:Arabidopsis Proteins / Q000235:genetics / Q000378:metabolism; D018533:Biomass; D002338:Carotenoids / Q000378:metabolism; D002734:Chlorophyll / Q000378:metabolism; D004777:Environment; D035264:Flowers / Q000187:drug effects / Q000235:genetics / Q000254:growth & development / Q000528:radiation effects; D018506:Gene Expression Regulation, Plant / Q000187:drug effects / Q000528:radiation effects; D017343:Genes, Plant / Q000235:genetics; D018525:Germination / Q000502:physiology; D008027:Light; D009154:Mutation / Q000235:genetics*; D009584:Nitrogen / Q000494:pharmacology; D018515:Plant Leaves / Q000187:drug effects / Q000502:physiology / Q000528:radiation effects; D013312:Stress, Physiological / Q000187:drug effects / Q000235:genetics / Q000528:radiation effects
chemical_list: D000872:Anthocyanins; D029681:Arabidopsis Proteins; D002734:Chlorophyll; D002338:Carotenoids; D009584:Nitrogen