Naumann C, Heisters M, Brandt W, Janitza P, Alfs C, Tang N, Toto Nienguesso A, Ziegler J, Imre R, Mechtler K, Dagdas Y, Hoehenwarter W, Sawers G, Quint M, Abel S. Bacterial-type ferroxidase tunes iron-dependent phosphate sensing during Arabidopsis root development.
Curr Biol 2022;
32:2189-2205.e6. [PMID:
35472311 PMCID:
PMC9168544 DOI:
10.1016/j.cub.2022.04.005]
[Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2021] [Revised: 02/21/2022] [Accepted: 04/04/2022] [Indexed: 12/02/2022]
Abstract
Access to inorganic phosphate (Pi), a principal intermediate of energy and nucleotide metabolism, profoundly affects cellular activities and plant performance. In most soils, antagonistic Pi-metal interactions restrict Pi bioavailability, which guides local root development to maximize Pi interception. Growing root tips scout the essential but immobile mineral nutrient; however, the mechanisms monitoring external Pi status are unknown. Here, we show that Arabidopsis LOW PHOSPHATE ROOT 1 (LPR1), one key determinant of Fe-dependent Pi sensing in root meristems, encodes a novel ferroxidase of high substrate specificity and affinity (apparent KM ∼ 2 μM Fe2+). LPR1 typifies an ancient, Fe-oxidizing multicopper protein family that evolved early upon bacterial land colonization. The ancestor of streptophyte algae and embryophytes (land plants) acquired LPR1-type ferroxidase from soil bacteria via horizontal gene transfer, a hypothesis supported by phylogenomics, homology modeling, and biochemistry. Our molecular and kinetic data on LPR1 regulation indicate that Pi-dependent Fe substrate availability determines LPR1 activity and function. Guided by the metabolic lifestyle of extant sister bacterial genera, we propose that Arabidopsis LPR1 monitors subtle concentration differentials of external Fe availability as a Pi-dependent cue to adjust root meristem maintenance via Fe redox signaling and cell wall modification. We further hypothesize that the acquisition of bacterial LPR1-type ferroxidase by embryophyte progenitors facilitated the evolution of local Pi sensing and acquisition during plant terrestrialization.
Arabidopsis thaliana LPR1 multicopper oxidase typifies a novel ferroxidase cohort
Fe availability tunes LPR1-dependent root responses to phosphate (Pi) limitation
LPR1 specificity links Fe-Pi interactions to root Pi sensing via redox cycling
Streptophyte ancestors acquired LPR1-type ferroxidase from soil bacteria by HGT
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