2024-03-28T17:47:12Z
https://tsukuba.repo.nii.ac.jp/oai
oai:tsukuba.repo.nii.ac.jp:00053753
2022-04-27T09:27:48Z
160:2745
3:62:5591:5939
Taming chlorophylls by early eukaryotes underpinned algal interactions and the diversification of the eukaryotes on the oxygenated Earth
平川, 泰久
ヒラカワ, ヨシヒサ
HIRAKAWA, Yoshihisa
Kashiyama, Yuichiro
Yokoyama, Akiko
Shiratori, Takashi
Hess, Sebastian
Not, Fabrice
Bachy, Charles
Gutierrez-Rodriguez, Andres
Kawahara, Jun
Suzaki, Toshinobu
Nakazawa, Masami
Ishikawa, Takahiro
Maruyama, Moe
Wang, Mengyun
Chen, Man
Gong, Yingchun
Seto, Kensuke
Kagami, Maiko
Hamamoto, Yoko
Honda, Daiske
Umetani, Takahiro
Shihongi, Akira
Kayama, Motoki
Matsuda, Toshiki
Taira, Junya
Yabuki, Akinori
Tsuchiya, Masashi
Kawaguchi, Akane
Nomura, Mami
Nakamura, Atsushi
Namba, Noriaki
Matsumoto, Mitsufumi
Tanaka, Tsuyoshi
Yoshino, Tomoko
Higuchi, Rina
Yamamoto, Akihiro
Maruyama, Tadanobu
Yamaguchi, Aika
Uzuka, Akihiro
Miyagishima, Shinya
Tanifuji, Goro
Kawachi, Masanobu
Kinoshita, Yusuke
Tamiaki, Hitoshi
© The Author(s) 2019. This article is published with open access
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Extant eukaryote ecology is primarily sustained by oxygenic photosynthesis, in which chlorophylls play essential roles. The exceptional photosensitivity of chlorophylls allows them to harvest solar energy for photosynthesis, but on the other hand, they also generate cytotoxic reactive oxygen species. A risk of such phototoxicity of the chlorophyll must become particularly prominent upon dynamic cellular interactions that potentially disrupt the mechanisms that are designed to quench photoexcited chlorophylls in the phototrophic cells. Extensive examination of a wide variety of phagotrophic, parasitic, and phototrophic microeukaryotes demonstrates that a catabolic process that converts chlorophylls into nonphotosensitive 132,173-cyclopheophorbide enols (CPEs) is phylogenetically ubiquitous among extant eukaryotes. The accumulation of CPEs is identified in phagotrophic algivores belonging to virtually all major eukaryotic assemblages with the exception of Archaeplastida, in which no algivorous species have been reported. In addition, accumulation of CPEs is revealed to be common among phototrophic microeukaryotes (i.e., microalgae) along with dismantling of their secondary chloroplasts. Thus, we infer that CPE-accumulating chlorophyll catabolism (CACC) primarily evolved among algivorous microeukaryotes to detoxify chlorophylls in an early stage of their evolution. Subsequently, it also underpinned photosynthetic endosymbiosis by securing close interactions with photosynthetic machinery containing abundant chlorophylls, which led to the acquisition of secondary chloroplasts. Our results strongly suggest that CACC, which allowed the consumption of oxygenic primary producers, ultimately permitted the successful radiation of the eukaryotes throughout and after the late Proterozoic global oxygenation.
Nature
2019-02
eng
journal article
http://hdl.handle.net/2241/00159171
https://tsukuba.repo.nii.ac.jp/records/53753
30809012
10.1038/s41396-019-0377-0
1751-7362
AA12230488
The ISME Journal
13
8
1899
1910
https://tsukuba.repo.nii.ac.jp/record/53753/files/ISMEJ_13-8.pdf
application/pdf
2.9 MB
2019-12-16