title: Patterns of plant biomass partitioning depend on nitrogen source.
abstract: Nitrogen (N) availability is a strong determinant of plant biomass partitioning, but the role of different N sources in this process is unknown. Plants inhabiting low productivity ecosystems typically partition a large share of total biomass to belowground structures. In these systems, organic N may often dominate plant available N. With increasing productivity, plant biomass partitioning shifts to aboveground structures, along with a shift in available N to inorganic forms of N. We tested the hypothesis that the form of N taken up by plants is an important determinant of plant biomass partitioning by cultivating Arabidopsis thaliana on different N source mixtures. Plants grown on different N mixtures were similar in size, but those supplied with organic N displayed a significantly greater root fraction. ¹⁵N labelling suggested that, in this case, a larger share of absorbed organic N was retained in roots and split-root experiments suggested this may depend on a direct incorporation of absorbed amino acid N into roots. These results suggest the form of N acquired affects plant biomass partitioning and adds new information on the interaction between N and biomass partitioning in plants.
authors.affiliation: Department of Forest Genetics and Plant Physiology Swedish University of Agricultural Sciences, Umeå, Sweden.
authors.forename: Camila Aguetoni
authors.initials: CA
authors.lastname: Cambui
authors.forename: Henrik
authors.initials: H
authors.lastname: Svennerstam
authors.forename: Linda
authors.initials: L
authors.lastname: Gruffman
authors.forename: Annika
authors.initials: A
authors.lastname: Nordin
authors.forename: Ulrika
authors.initials: U
authors.lastname: Ganeteg
authors.forename: Torgny
authors.initials: T
authors.lastname: Näsholm
mesh_terms: D017360:Arabidopsis / Q000254:growth & development / Q000378:metabolism; D018533:Biomass; D009584:Nitrogen / Q000378:metabolism*; D063245:Plant Development; D010944:Plants / Q000378:metabolism*
chemical_list: D009584:Nitrogen