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Tóth D, Kuntam S, Ferenczi Á, Vidal-Meireles A, Kovács L, Wang L, Sarkadi Z, Migh E, Szentmihályi K, Tengölics R, Neupert J, Bock R, Jonikas MC, Molnar A, Tóth SZ. Chloroplast phosphate transporter CrPHT4-7 regulates phosphate homeostasis and photosynthesis in Chlamydomonas. Plant Physiol 2024; 194:1646-1661. [PMID: 37962583 PMCID: PMC10904345 DOI: 10.1093/plphys/kiad607] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/08/2023] [Revised: 10/18/2023] [Accepted: 10/19/2023] [Indexed: 11/15/2023]
Abstract
In eukaryotic cells, phosphorus is assimilated and utilized primarily as phosphate (Pi). Pi homeostasis is mediated by transporters that have not yet been adequately characterized in green algae. This study reports on PHOSPHATE TRANSPORTER 4-7 (CrPHT4-7) from Chlamydomonas reinhardtii, a member of the PHT4 transporter family, which exhibits remarkable similarity to AtPHT4;4 from Arabidopsis (Arabidopsis thaliana), a chloroplastic ascorbate transporter. Using fluorescent protein tagging, we show that CrPHT4-7 resides in the chloroplast envelope membrane. Crpht4-7 mutants, generated by the CRISPR/Cas12a-mediated single-strand templated repair, show retarded growth, especially in high light, reduced ATP level, strong ascorbate accumulation, and diminished non-photochemical quenching in high light. On the other hand, total cellular phosphorous content was unaffected, and the phenotype of the Crpht4-7 mutants could not be alleviated by ample Pi supply. CrPHT4-7-overexpressing lines exhibit enhanced biomass accumulation under high light conditions in comparison with the wild-type strain. Expressing CrPHT4-7 in a yeast (Saccharomyces cerevisiae) strain lacking Pi transporters substantially recovered its slow growth phenotype, demonstrating that CrPHT4-7 transports Pi. Even though CrPHT4-7 shows a high degree of similarity to AtPHT4;4, it does not display any substantial ascorbate transport activity in yeast or intact algal cells. Thus, the results demonstrate that CrPHT4-7 functions as a chloroplastic Pi transporter essential for maintaining Pi homeostasis and photosynthesis in C. reinhardtii.
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Affiliation(s)
- Dávid Tóth
- Institute of Plant Biology, HUN-REN Biological Research Centre, H-6726 Szeged, Hungary
- Doctoral School of Biology, University of Szeged, H-6722 Szeged, Hungary
| | - Soujanya Kuntam
- Institute of Plant Biology, HUN-REN Biological Research Centre, H-6726 Szeged, Hungary
| | - Áron Ferenczi
- Institute of Molecular Plant Sciences, School of Biological Sciences, King's Buildings, University of Edinburgh, Edinburgh EH9 3BF, UK
| | - André Vidal-Meireles
- Institute of Plant Biology, HUN-REN Biological Research Centre, H-6726 Szeged, Hungary
| | - László Kovács
- Institute of Plant Biology, HUN-REN Biological Research Centre, H-6726 Szeged, Hungary
| | - Lianyong Wang
- Department of Molecular Biology, Princeton University, Lewis Thomas Laboratory, Princeton, NJ 08544, USA
| | - Zsuzsa Sarkadi
- Institute of Biochemistry, HUN-REN Biological Research Centre, H-6726 Szeged, Hungary
- Hungarian Centre of Excellence for Molecular Medicine—Biological Research Centre Metabolic Systems Biology Research Group, H-6726 Szeged, Hungary
| | - Ede Migh
- Institute of Biochemistry, HUN-REN Biological Research Centre, H-6726 Szeged, Hungary
| | - Klára Szentmihályi
- Institute of Materials and Environmental Chemistry, Research Centre for Natural Sciences, H-1117 Budapest, Hungary
| | - Roland Tengölics
- Hungarian Centre of Excellence for Molecular Medicine—Biological Research Centre Metabolic Systems Biology Research Group, H-6726 Szeged, Hungary
- Metabolomics Lab, Core Facilities, HUN-REN Biological Research Centre, H-6726 Szeged, Hungary
| | - Juliane Neupert
- Max Planck Institute of Molecular Plant Physiology, D-14476 Potsdam-Golm, Germany
| | - Ralph Bock
- Max Planck Institute of Molecular Plant Physiology, D-14476 Potsdam-Golm, Germany
| | - Martin C Jonikas
- Department of Molecular Biology, Princeton University, Lewis Thomas Laboratory, Princeton, NJ 08544, USA
- Howard Hughes Medical Institute, Princeton University, Lewis Thomas Laboratory, Princeton, NJ 08544, USA
| | - Attila Molnar
- Institute of Molecular Plant Sciences, School of Biological Sciences, King's Buildings, University of Edinburgh, Edinburgh EH9 3BF, UK
| | - Szilvia Z Tóth
- Institute of Plant Biology, HUN-REN Biological Research Centre, H-6726 Szeged, Hungary
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