Characterization of <i>Chlamydomonas reinhardtii</i> Mutants That Exhibit Strong Positive Phototaxis
The most motile phototrophic organisms exhibit photo-induced behavioral responses (photobehavior) to inhabit better light conditions for photosynthesis. The unicellular green alga <i>Chlamydomonas reinhardtii</i> is an excellent model organism to study photobehavior. Several years ago, w...
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MDPI AG
2021-07-01
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| Series: | Plants |
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| Online Access: | https://www.mdpi.com/2223-7747/10/7/1483 |
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| author | Jun Morishita Ryutaro Tokutsu Jun Minagawa Toru Hisabori Ken-ichi Wakabayashi |
| author_facet | Jun Morishita Ryutaro Tokutsu Jun Minagawa Toru Hisabori Ken-ichi Wakabayashi |
| author_sort | Jun Morishita |
| collection | DOAJ |
| description | The most motile phototrophic organisms exhibit photo-induced behavioral responses (photobehavior) to inhabit better light conditions for photosynthesis. The unicellular green alga <i>Chlamydomonas reinhardtii</i> is an excellent model organism to study photobehavior. Several years ago, we found that <i>C. reinhardtii</i> cells reverse their phototactic signs (i.e., positive and negative phototaxis) depending on the amount of reactive oxygen species (ROS) accumulated in the cell. However, its molecular mechanism is unclear. In this study, we isolated seven mutants showing positive phototaxis, even after the induction of negative phototaxis (<i>ap1~7</i>: always positive) to understand the ROS-dependent regulatory mechanism for the phototactic sign. We found no common feature in the mutants regarding their growth, high-light tolerance, and photosynthetic phenotypes. Interestingly, five of them grew faster than the wild type. These data suggest that the ROS-dependent regulation of the phototactic sign is not a single pathway and is affected by various cellular factors. Additionally, the isolation and analyses of mutants with defects in phototactic-sign regulation may provide clues for their application to the efficient cultivation of algae. |
| first_indexed | 2024-03-10T09:27:34Z |
| format | Article |
| id | doaj.art-6e995dbbefb040bf818c8ad803887c08 |
| institution | Directory Open Access Journal |
| issn | 2223-7747 |
| language | English |
| last_indexed | 2024-03-10T09:27:34Z |
| publishDate | 2021-07-01 |
| publisher | MDPI AG |
| record_format | Article |
| series | Plants |
| spelling | doaj.art-6e995dbbefb040bf818c8ad803887c082023-11-22T04:44:57ZengMDPI AGPlants2223-77472021-07-01107148310.3390/plants10071483Characterization of <i>Chlamydomonas reinhardtii</i> Mutants That Exhibit Strong Positive PhototaxisJun Morishita0Ryutaro Tokutsu1Jun Minagawa2Toru Hisabori3Ken-ichi Wakabayashi4Laboratory for Chemistry and Life Science, Institute of Innovative Research, Tokyo Institute of Technology, Yokohama 226-8503, JapanDivision of Environmental Photobiology, National Institute for Basic Biology, Okazaki 444-8585, JapanDivision of Environmental Photobiology, National Institute for Basic Biology, Okazaki 444-8585, JapanLaboratory for Chemistry and Life Science, Institute of Innovative Research, Tokyo Institute of Technology, Yokohama 226-8503, JapanLaboratory for Chemistry and Life Science, Institute of Innovative Research, Tokyo Institute of Technology, Yokohama 226-8503, JapanThe most motile phototrophic organisms exhibit photo-induced behavioral responses (photobehavior) to inhabit better light conditions for photosynthesis. The unicellular green alga <i>Chlamydomonas reinhardtii</i> is an excellent model organism to study photobehavior. Several years ago, we found that <i>C. reinhardtii</i> cells reverse their phototactic signs (i.e., positive and negative phototaxis) depending on the amount of reactive oxygen species (ROS) accumulated in the cell. However, its molecular mechanism is unclear. In this study, we isolated seven mutants showing positive phototaxis, even after the induction of negative phototaxis (<i>ap1~7</i>: always positive) to understand the ROS-dependent regulatory mechanism for the phototactic sign. We found no common feature in the mutants regarding their growth, high-light tolerance, and photosynthetic phenotypes. Interestingly, five of them grew faster than the wild type. These data suggest that the ROS-dependent regulation of the phototactic sign is not a single pathway and is affected by various cellular factors. Additionally, the isolation and analyses of mutants with defects in phototactic-sign regulation may provide clues for their application to the efficient cultivation of algae.https://www.mdpi.com/2223-7747/10/7/1483<i>Chlamydomonas</i>phototaxisphotosynthesisphotoprotection |
| spellingShingle | Jun Morishita Ryutaro Tokutsu Jun Minagawa Toru Hisabori Ken-ichi Wakabayashi Characterization of <i>Chlamydomonas reinhardtii</i> Mutants That Exhibit Strong Positive Phototaxis Plants <i>Chlamydomonas</i> phototaxis photosynthesis photoprotection |
| title | Characterization of <i>Chlamydomonas reinhardtii</i> Mutants That Exhibit Strong Positive Phototaxis |
| title_full | Characterization of <i>Chlamydomonas reinhardtii</i> Mutants That Exhibit Strong Positive Phototaxis |
| title_fullStr | Characterization of <i>Chlamydomonas reinhardtii</i> Mutants That Exhibit Strong Positive Phototaxis |
| title_full_unstemmed | Characterization of <i>Chlamydomonas reinhardtii</i> Mutants That Exhibit Strong Positive Phototaxis |
| title_short | Characterization of <i>Chlamydomonas reinhardtii</i> Mutants That Exhibit Strong Positive Phototaxis |
| title_sort | characterization of i chlamydomonas reinhardtii i mutants that exhibit strong positive phototaxis |
| topic | <i>Chlamydomonas</i> phototaxis photosynthesis photoprotection |
| url | https://www.mdpi.com/2223-7747/10/7/1483 |
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