著者

Tomonori Kashimoto Keita Miyake Mayuko Sato Kaisei Maeda Chikahiro Matsumoto Masahiko Ikeuchi Kiminori Toyooka Satoru Watanabe Yu Kanesaki Rei Narikawa

出版者

Applied Microbiology, Molecular and Cellular Biosciences Research Foundation

雑誌

The Journal of General and Applied Microbiology (ISSN:00221260)

巻号頁・発行日

pp.2019.11.008, (Released:2020-03-07)

参考文献数

43

被引用文献数

5

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The cyanobacterium Acaryochloris marina MBIC 11017 (A. marina 11017) possesses chlorophyll d (Chl. d) peaking at 698 nm as photosystem reaction center pigments, instead of chlorophyll a (Chl. a) peaking at 665 nm. About 95% of the total chlorophylls is Chl. d in A. marina 11017. In addition, A. marina 11017 possesses phycobilisome (PBS) supercomplex to harvest orange light and to transfer the absorbing energy to the photosystems. In this context, A. marina 11017 utilizes both far-red and orange light as the photosynthetic energy source. In the present study, we incubated A. marina 11017 cells under monochromatic orange and far-red light conditions and performed transcriptional and morphological studies by RNA-seq analysis and electron microscopy. Cellular absorption spectra, transcriptomic profiles, and microscopic observations demonstrated that PBS was highly accumulated under an orange light condition relative to a far-red light condition. Notably, transcription of one cpcBA operon encoding the phycobiliprotein of the phycocyanin was up-regulated under the orange light condition, but another operon was constitutively expressed under both conditions, indicating functional diversification of these two operons for light harvesting. Taking the other observations into consideration, we could illustrate the photoacclimation processes of A. marina 11017 in response to orange and far-red light conditions in detail.

著者

Toshiyuki Takahashi Mayuko Sato Kiminori Toyooka Hisayoshi Nozaki

出版者

日本メンデル協会、国際細胞学会

雑誌

CYTOLOGIA (ISSN:00114545)

巻号頁・発行日

vol.79, no.1, pp.119-123, 2014-03-25 (Released:2014-07-15)

参考文献数

18

被引用文献数

7 11

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Cyanophora paradoxa is an enigmatic biflagellate that may represent the first photosynthetic eukaryote morphologically. This alga has been widely studied as a model organism of primitive phototrophs. However, surface ornamentations of the vegetative cells have not been examined using ultra-high resolution field emission (FE) scanning electron microscopy (SEM). In the present study, C. paradoxa NIES-547 vegetative cells were examined using FE-SEM and compared with the data using conventional SEM. Our FE-SEM images demonstrated that the cell surface was ornamented with angular fenestrations framed by ridges. In contrast, conventional SEM did not reveal similar surface ornamentation. Transmission electron microscopy showed the ridge was formed by the edges of overlapping or attaching outermost plate vesicles at the cell periphery.