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Mg-dechelatase is involved in the formation of photosystem II but not in chlorophyll degradation in Chlamydomonas reinhardtii
| Title: | Mg-dechelatase is involved in the formation of photosystem II but not in chlorophyll degradation in Chlamydomonas reinhardtii |
| Authors: | Chen, Ying Browse this author | | Shimoda, Yousuke Browse this author | | Yokono, Makio Browse this author | | Ito, Hisashi Browse this author | | Tanaka, Ayumi Browse this author →KAKEN DB |
| Keywords: | STAY-GREEN | | Mg-dechelatase | | photosystem II formation | | chlorophyll degradation | | pheophytin a |
| Issue Date: | Mar-2019 |
| Publisher: | John Wiley & Sons |
| Journal Title: | Plant journal |
| Volume: | 97 |
| Issue: | 6 |
| Start Page: | 1022 |
| End Page: | 1031 |
| Publisher DOI: | 10.1111/tpj.14174 |
| Abstract: | The STAY-GREEN (SGR) gene encodes Mg-dechelatase which catalyzes the conversion of chlorophyll (Chl) a to pheophytin (Pheo) a. This reaction is the first and most important regulatory step in the Chl degradation pathway. Conversely, Pheo a is an indispensable molecule in photosystem (PS) II, suggesting the involvement of SGR in the formation of PSII. To investigate the physiological functions of SGR, we isolated Chlamydomonas sgr mutants by screening an insertion-mutant library. The sgr mutants had reduced maximum quantum efficiency of PSII (F-v/F-m) and reduced Pheo a levels. These phenotypes were complemented by the introduction of the Chlamydomonas SGR gene. Blue Native polyacrylamide gel electrophoresis and immunoblotting analysis showed that although PSII levels were reduced in the sgr mutants, PSI and light-harvesting Chl a/b complex levels were unaffected. Under nitrogen starvation conditions, Chl degradation proceeded in the sgr mutants as in the wild type, indicating that Chlamydomonas SGR is not required for Chl degradation and primarily contributes to the formation of PSII. In contrast, in the Arabidopsis sgr triple mutant (sgrl sgr2 sgrL), which completely lacks SGR activity, PSII was synthesized normally. These results suggest that the Arabidopsis SGR participates in Chl degradation while the Chlamydomonas SGR participates in PSII formation despite having the same catalytic property. |
| Rights: | This is the peer reviewed version of the following article: [https://onlinelibrary.wiley.com/doi/full/10.1111/tpj.14174], which has been published in final form at [https://doi.org/10.1111/tpj.14174]. This article may be used for non-commercial purposes in accordance with Wiley Terms and Conditions for Self-Archiving. |
| Type: | article (author version) |
| URI: | http://hdl.handle.net/2115/76847 |
| Appears in Collections: | 低温科学研究所 (Institute of Low Temperature Science) > 雑誌発表論文等 (Peer-reviewed Journal Articles, etc)
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Submitter: 伊藤 寿
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