Chloroplast-localized BICAT proteins shape stromal calcium signals and are required for efficient photosynthesis
© 2018 The Authors. New Phytologist © 2018 New Phytologist Trust.
| Veröffentlicht in: | The New phytologist. - 1979. - 221(2019), 2 vom: 18. Jan., Seite 866-880 |
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| 1. Verfasser: | |
| Weitere Verfasser: | , , , , , , , , |
| Format: | Online-Aufsatz |
| Sprache: | English |
| Veröffentlicht: |
2019
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| Zugriff auf das übergeordnete Werk: | The New phytologist |
| Schlagworte: | Journal Article Research Support, Non-U.S. Gov't Arabidopsis thaliana calcium signal calcium transport chloroplast photosynthesis Arabidopsis Proteins BICAT1 protein, Arabidopsis BICAT2 protein, Arabidopsis mehr... |
| Zusammenfassung: | © 2018 The Authors. New Phytologist © 2018 New Phytologist Trust. The photosynthetic machinery of plants must be regulated to maximize the efficiency of light reactions and CO2 fixation. Changes in free Ca2+ in the stroma of chloroplasts have been observed at the transition between light and darkness, and also in response to stress stimuli. Such Ca2+ dynamics have been proposed to regulate photosynthetic capacity. However, the molecular mechanisms of Ca2+ fluxes in the chloroplasts have been unknown. By employing a Ca2+ reporter-based approach, we identified two chloroplast-localized Ca2+ transporters in Arabidopsis thaliana, BICAT1 and BICAT2, that determine the amplitude of the darkness-induced Ca2+ signal in the chloroplast stroma. BICAT2 mediated Ca2+ uptake across the chloroplast envelope, and its knockout mutation strongly dampened the dark-induced [Ca2+ ]stroma signal. Conversely, this Ca2+ transient was increased in knockout mutants of BICAT1, which transports Ca2+ into the thylakoid lumen. Knockout mutation of BICAT2 caused severe defects in chloroplast morphology, pigmentation and photosynthetic light reactions, rendering bicat2 mutants barely viable under autotrophic growth conditions, while bicat1 mutants were less affected. These results show that BICAT transporters play a role in chloroplast Ca2+ homeostasis. They are also involved in the regulation of photosynthesis and plant productivity. Further work will be required to reveal whether the effect on photosynthesis is a direct result of their role as Ca2+ transporters |
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| Beschreibung: | Date Completed 18.02.2020 Date Revised 30.09.2020 published: Print-Electronic Citation Status MEDLINE |
| ISSN: | 1469-8137 |
| DOI: | 10.1111/nph.15407 |