Chloroplast magnesium transporters play essential but differential roles in maintaining magnesium homeostasis
Research output: Contribution to journal › Journal article › Research › peer-review
Standard
Chloroplast magnesium transporters play essential but differential roles in maintaining magnesium homeostasis. / Dukic, Emilija; van Maldegem, Kim A.; Shaikh, Kashif Mohd; Fukuda, Kento; Töpel, Mats; Solymosi, Katalin; Hellsten, Jonna; Hansen, Thomas Hesselhøj; Husted, Søren; Higgins, John; Sano, Satoshi; Ishijima, Sumio; Spetea, Cornelia.
In: Frontiers in Plant Science, Vol. 14, 1221436, 2023.Research output: Contribution to journal › Journal article › Research › peer-review
Harvard
APA
Vancouver
Author
Bibtex
}
RIS
TY - JOUR
T1 - Chloroplast magnesium transporters play essential but differential roles in maintaining magnesium homeostasis
AU - Dukic, Emilija
AU - van Maldegem, Kim A.
AU - Shaikh, Kashif Mohd
AU - Fukuda, Kento
AU - Töpel, Mats
AU - Solymosi, Katalin
AU - Hellsten, Jonna
AU - Hansen, Thomas Hesselhøj
AU - Husted, Søren
AU - Higgins, John
AU - Sano, Satoshi
AU - Ishijima, Sumio
AU - Spetea, Cornelia
N1 - Publisher Copyright: Copyright © 2023 Dukic, van Maldegem, Shaikh, Fukuda, Töpel, Solymosi, Hellsten, Hansen, Husted, Higgins, Sano, Ishijima and Spetea.
PY - 2023
Y1 - 2023
N2 - Magnesium (Mg2+) is essential for photosynthesis in the chloroplasts of land plants and algae. Being the central ion of chlorophyll, cofactor and activator of many photosynthetic enzymes including RuBisCO, magnesium-deficient plants may suffer from leaf chlorosis symptoms and retarded growth. Therefore, the chloroplast Mg2+ concentration is tightly controlled by magnesium transport proteins. Recently, three different transporters from two distinct families have been identified in the chloroplast inner envelope of the model plant Arabidopsis thaliana: MGT10, MGR8, and MGR9. Here, we assess the individual roles of these three proteins in maintaining chloroplast Mg2+ homeostasis and regulating photosynthesis, and if their role is conserved in the model green alga Chlamydomonas reinhardtii. Phylogenetic analysis and heterologous expression revealed that the CorC-like MGR8 and MGR9 transport Mg2+ by a different mechanism than the CorA-like MGT10. MGR8 and MGT10 genes are highest expressed in leaves, indicating a function in chloroplast Mg2+ transport. MGR9 is important for chloroplast function and plant adaptation in conditions of deficiency or excess of Mg2+. Transmission electron microscopy indicated that MGT10 plays a differential role in thylakoid stacking than MGR8 and MGR9. Furthermore, we report that MGR8, MGR9, and MGT10 are involved in building up the pH gradient across the thylakoid membrane and activating photoprotection in conditions of excess light, however the mechanism has not been resolved yet. While there are no chloroplast MGR-like transporters in Chlamydomonas, we show that MRS4 is a homolog of MGT10, that is required for photosynthesis and cell growth. Taken together, our findings reveal that the studied Mg2+ transporters play essential but differential roles in maintaining chloroplast Mg2+ homeostasis.
AB - Magnesium (Mg2+) is essential for photosynthesis in the chloroplasts of land plants and algae. Being the central ion of chlorophyll, cofactor and activator of many photosynthetic enzymes including RuBisCO, magnesium-deficient plants may suffer from leaf chlorosis symptoms and retarded growth. Therefore, the chloroplast Mg2+ concentration is tightly controlled by magnesium transport proteins. Recently, three different transporters from two distinct families have been identified in the chloroplast inner envelope of the model plant Arabidopsis thaliana: MGT10, MGR8, and MGR9. Here, we assess the individual roles of these three proteins in maintaining chloroplast Mg2+ homeostasis and regulating photosynthesis, and if their role is conserved in the model green alga Chlamydomonas reinhardtii. Phylogenetic analysis and heterologous expression revealed that the CorC-like MGR8 and MGR9 transport Mg2+ by a different mechanism than the CorA-like MGT10. MGR8 and MGT10 genes are highest expressed in leaves, indicating a function in chloroplast Mg2+ transport. MGR9 is important for chloroplast function and plant adaptation in conditions of deficiency or excess of Mg2+. Transmission electron microscopy indicated that MGT10 plays a differential role in thylakoid stacking than MGR8 and MGR9. Furthermore, we report that MGR8, MGR9, and MGT10 are involved in building up the pH gradient across the thylakoid membrane and activating photoprotection in conditions of excess light, however the mechanism has not been resolved yet. While there are no chloroplast MGR-like transporters in Chlamydomonas, we show that MRS4 is a homolog of MGT10, that is required for photosynthesis and cell growth. Taken together, our findings reveal that the studied Mg2+ transporters play essential but differential roles in maintaining chloroplast Mg2+ homeostasis.
KW - Arabidopsis thaliana
KW - Chlamydomonas reinhardtii
KW - chlorophyll fluorescence
KW - chloroplast
KW - magnesium homeostasis
KW - magnesium transporter
KW - photosynthesis
U2 - 10.3389/fpls.2023.1221436
DO - 10.3389/fpls.2023.1221436
M3 - Journal article
C2 - 37692441
AN - SCOPUS:85170404824
VL - 14
JO - Frontiers in Plant Science
JF - Frontiers in Plant Science
SN - 1664-462X
M1 - 1221436
ER -
ID: 369253568