Journal Article

Functional PTB phosphate transporters are present in streptophyte algae and early diverging land plants

Pinson, Benoît, Proust, Helene, H, Lesly-Veillard, Alexis, Champion, Clément, Hetherington, Alexander, J, Colbalchini, Florine, P L, Kelly, Steven, Institut Jean-Pierre Bourgin (IJPB) ; Institut National de la Recherche Agronomique (INRA)-AgroParisTech, Breuninger, Holger, Interactions Arbres-Microorganismes (IAM) ; Institut National de la Recherche Agronomique (INRA)-Université de Lorraine (UL), Dolan, Liam, Bonnot, Clémence, Institut de biochimie et génétique cellulaires (IBGC) ; Université de Bordeaux (UB)-Centre National de la Recherche Scientifique (CNRS)

2017

Overview

Two inorganic phosphate (Pi) uptake mechanisms operate in streptophytes and chloro-phytes, the two lineages of green plants. PHOSPHATE TRANSPORTER B (PTB) proteins are hypothesized to be the Na + /Pi symporters catalysing Pi uptake in chlorophytes, whereas PHOSPHATE TRANSPORTER 1 (PHT1) proteins are the H + /Pi symporters that carry out Pi uptake in angiosperms. PHT1 proteins are present in all streptophyte lineages. However, Pi uptake in streptophyte algae and marine angiosperms requires Na + influx, suggesting that Na + /Pi symporters also function in some streptophytes. We tested the hypothesis that Na + /Pi symporters exist in streptophytes. We identified PTB sequences in streptophyte genomes. Core PTB proteins are present at the plasma membrane of the liverwort Marchantia polymorpha. The expression of M. polymorpha core PTB proteins in the Saccharomyces cerevisiae pho2 mutant defective in high-affinity Pi transport rescues growth in low-Pi environments. Moreover, levels of core PTB mRNAs of M. polymorpha and the streptophyte alga Coleochaete nitellarum are higher in low-Pi than in Pi-replete conditions, consistent with a role in Pi uptake from the environment. We conclude that land plants inherited two Pi uptake mechanisms-mediated by the PTB and PHT1 proteins, respectively-from their streptophyte algal ancestor. Both systems operate in parallel in extant early diverging land plants.

• Publisher: Wiley,CCSD,New Phytologist Trust,Wiley Subscription Services, Inc
• Subject: Algae / Amino Acid Motifs / Amino Acid Sequence / Angiospermae / Angiosperms / Aquatic plants / Chlorophyta - drug effects / Chlorophyta - genetics / Chlorophyta - metabolism / Coleochaete / Coleochaete nitellarum / Conserved Sequence / early diverging land plants / Embryophyta - drug effects / Embryophyta - metabolism / embryophytes / Fungi / Gene sequencing / Genetic Complementation Test / genome / Genomes / Hydrophobic and Hydrophilic Interactions / Life Sciences / Marchantia - drug effects / Marchantia - metabolism / Marchantia polymorpha / messenger RNA / mosses and liverworts / mutants / Mutation - genetics / Phosphate Transport Proteins - chemistry / Phosphate Transport Proteins - genetics / Phosphate Transport Proteins - metabolism / Phosphate transporter / Phosphates / Phosphates - pharmacology / Phylogeny / Pi uptake / plasma membrane / Proteins / protons / PTB Pi transporters / RNA, Messenger - genetics / RNA, Messenger - metabolism / Saccharomyces cerevisiae / Saccharomyces cerevisiae - metabolism / sodium / streptophyte algae / Subcellular Fractions - drug effects / Subcellular Fractions - metabolism / symporters / Uptake / uptake mechanisms