The effect of iron on the primary root elongation of Arabidopsis during phosphate deficiency.
Root architecture differences have been linked to the survival of plants on phosphate (P)-deficient soils, as well as to the improved yields of P-efficient crop cultivars. To understand how these differences arise, we have studied the root architectures of P-deficient Arabidopsis (Arabidopsis thaliana Columbia-0) plants. A striking aspect of the root architecture of these plants is that their primary root elongation is inhibited when grown on P-deficient medium. Here, we present evidence suggesting that this inhibition is a result of iron (Fe) toxicity. When the Fe concentration in P-deficient medium is reduced, we observe elongation of the primary root without an increase in P availability or a corresponding change in the expression of P deficiency-regulated genes. Recovery of the primary root elongation is associated with larger plant weights, improved ability to take up P from the medium, and increased tissue P content. This suggests that manipulating Fe availability to a plant could be a valuable strategy for improving a plant's ability to tolerate P deficiency.
Ward
James T
JT
Department of Horticulture and Landscape Architecture, Purdue University, West Lafayette, Indiana 47907-1165, USA.
Lahner
Brett
B
Yakubova
Elena
E
Salt
David E
DE
Raghothama
Kashchandra G
KG
D017360:Arabidopsis / Q000235:genetics / Q000254:growth & development / Q000378:metabolism*; D029681:Arabidopsis Proteins / Q000235:genetics; D018506:Gene Expression Regulation, Plant; D017343:Genes, Plant; D007501:Iron / Q000378:metabolism*; D026901:Membrane Transport Proteins / Q000235:genetics; D009154:Mutation; D010710:Phosphates / Q000378:metabolism*; D018517:Plant Roots / Q000254:growth & development / Q000378:metabolism*
D029681:Arabidopsis Proteins; C469252:FRD3 protein, Arabidopsis; D026901:Membrane Transport Proteins; D010710:Phosphates; D007501:Iron