TY - JOUR
T1 - Diel magnesium fluctuations in chloroplasts contribute to photosynthesis in rice
AU - Li, Jian
AU - Yokosho, Kengo
AU - Liu, Sheng
AU - Cao, Hong Rui
AU - Yamaji, Naoki
AU - Zhu, Xin Guang
AU - Liao, Hong
AU - Ma, Jian Feng
AU - Chen, Zhi Chang
N1 - Funding Information:
We thank L. Li for providing the MM281 strain and the pTrc99A and AtMGT10-pTrc99A vectors. We thank T. Nagai for providing MARIO. We also thank R. Gardner for providing the CM66 strain and Y. Liu for providing pYLsgRNA-U6a. We further thank M. Qu for help with guiding the ΔpH measurements, and T. Walk and Golden Fidelity LLC for language editing. This work is financially supported by the China National Key Program for Research and Development (grant no. 2016YFD0100700 to Z.C.C. and H.L.) and the National Natural Science Foundation of China (grant no. 31672218 to Z.C.C.), and by a Grant-in-Aid for Specially Promoted Research (JSPS KAKENHI grant no. 16H06296 to J.F.M.).
Publisher Copyright:
© 2020, The Author(s), under exclusive licence to Springer Nature Limited.
PY - 2020/7/1
Y1 - 2020/7/1
N2 - Photosynthesis provides food, fibre and fuel that support our society; understanding the mechanisms controlling dynamic changes in this process helps identify new options to improve photosynthesis. Photosynthesis shows diel changes, which have been largely attributed to external light/dark conditions, as well as internal gene expression and the post-translational modification of critical enzymes. Here we report diel fluctuations of magnesium (Mg) in rice (Oryza sativa) chloroplasts, which may function as a rhythm regulator contributing to the post-translational regulation of photosynthetic CO2 assimilation in rice. We found that a chloroplast-localized Mg2+ transporter gene, OsMGT3, which is rhythmically expressed in leaf mesophyll cells, partly modulates Mg fluctuations in rice chloroplasts. Knockout of OsMGT3 substantially reduced Mg2+ uptake, as well as the amplitude of free Mg2+ fluctuations in chloroplasts, which was closely associated with a decrease in ribulose 1,5-bisphosphate carboxylase activity in vivo and a consequent decline in the photosynthetic rate. In addition, the mesophyll-specific overexpression of OsMGT3 remarkably improved photosynthetic efficiency and growth performance in rice. Taken together, these observations demonstrate that OsMGT3-dependent diel Mg fluctuations in chloroplasts may contribute to Mg-dependent enzyme activities for photosynthesis over the daily cycle. Enhancing Mg2+ input to chloroplasts could be a potential approach to improving photosynthetic efficiency in plants.
AB - Photosynthesis provides food, fibre and fuel that support our society; understanding the mechanisms controlling dynamic changes in this process helps identify new options to improve photosynthesis. Photosynthesis shows diel changes, which have been largely attributed to external light/dark conditions, as well as internal gene expression and the post-translational modification of critical enzymes. Here we report diel fluctuations of magnesium (Mg) in rice (Oryza sativa) chloroplasts, which may function as a rhythm regulator contributing to the post-translational regulation of photosynthetic CO2 assimilation in rice. We found that a chloroplast-localized Mg2+ transporter gene, OsMGT3, which is rhythmically expressed in leaf mesophyll cells, partly modulates Mg fluctuations in rice chloroplasts. Knockout of OsMGT3 substantially reduced Mg2+ uptake, as well as the amplitude of free Mg2+ fluctuations in chloroplasts, which was closely associated with a decrease in ribulose 1,5-bisphosphate carboxylase activity in vivo and a consequent decline in the photosynthetic rate. In addition, the mesophyll-specific overexpression of OsMGT3 remarkably improved photosynthetic efficiency and growth performance in rice. Taken together, these observations demonstrate that OsMGT3-dependent diel Mg fluctuations in chloroplasts may contribute to Mg-dependent enzyme activities for photosynthesis over the daily cycle. Enhancing Mg2+ input to chloroplasts could be a potential approach to improving photosynthetic efficiency in plants.
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U2 - 10.1038/s41477-020-0686-3
DO - 10.1038/s41477-020-0686-3
M3 - Article
C2 - 32541951
AN - SCOPUS:85088178140
SN - 2055-026X
VL - 6
SP - 848
EP - 859
JO - Nature Plants
JF - Nature Plants
IS - 7
ER -