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Sotta N, Sakamoto T, Kamiya T, Tabata R, Yamaguchi K, Shigenobu S, Yamada M, Hasebe M, Sawa S, Fujiwara T. NAC103 mutation alleviates DNA damage in an Arabidopsis thaliana mutant sensitive to excess boron. Front Plant Sci 2023; 14:1099816. [PMID: 37063182 PMCID: PMC10090426 DOI: 10.3389/fpls.2023.1099816] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 11/16/2022] [Accepted: 02/28/2023] [Indexed: 06/19/2023]
Abstract
Excess boron (B) is toxic to plants and thereby causes DNA damage and cell death in root meristems. However, the underlying mechanisms which link boron and DNA damage remain unclear. It has been reported that the rpt5a-6 mutant of the 26S proteasome is sensitive to excess boron, resulting in more frequent cell death in root meristem and reduced root elongation. In this study, we showed that a reduction in root growth in the rpt5a mutant in the presence of high boron levels is repressed by a mutation in NAC domain containing transcription factor NAC103, a substrate of the proteasome, which functions in the unfolded protein response pathway. The mutation in NAC103 alleviated excess-B-induced DNA damage and cell death in root meristems of the rpt5a mutant. Superoxide ( O 2 - ) staining with nitroblue tetrazolium revealed that boron stress causes O 2 - accumulation in root tips, which was higher in the rpt5a-6 mutant, whereas the accumulation was lower in the rpt5a-6 nac103-3 double mutant. Our work demonstrates the overall involvement of NAC103 in maintaining healthy root meristem under excess boron conditions in the absence of RPT5A proteasome subunit.
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Affiliation(s)
- Naoyuki Sotta
- Department of Applied Biological Chemistry, Graduate School of Agricultural and Life Sciences, The University of Tokyo, Tokyo, Japan
| | - Takuya Sakamoto
- Department of Applied Biological Science, Faculty of Science and Technology, Tokyo University of Science, Tokyo, Japan
| | - Takehiro Kamiya
- Department of Applied Biological Chemistry, Graduate School of Agricultural and Life Sciences, The University of Tokyo, Tokyo, Japan
| | - Ryo Tabata
- Graduate School of Science and Technology, Kumamoto University, Kumamoto, Japan
- Graduate School of Bioagricultural Sciences, Nagoya University, Nagoya, Japan
| | - Katsushi Yamaguchi
- National Institutes for Basic Biology, National Institutes of Natural Sciences, Okazaki, Japan
| | - Shuji Shigenobu
- National Institutes for Basic Biology, National Institutes of Natural Sciences, Okazaki, Japan
- School of Life Science, Graduate University for Advanced Studies, Okazaki, Japan
| | - Masashi Yamada
- Agricultural Biotechnology Research Center, Academia Sinica, Taipei, Taiwan
- Biotechnology Center in Southern Taiwan, Academia Sinica, Tainan, Taiwan
| | - Mitsuyasu Hasebe
- National Institutes for Basic Biology, National Institutes of Natural Sciences, Okazaki, Japan
- School of Life Science, Graduate University for Advanced Studies, Okazaki, Japan
| | - Shinichiro Sawa
- Graduate School of Science and Technology, Kumamoto University, Kumamoto, Japan
- International Research Center for Agricultural & Environmental Biology, Kumamoto University, Kumamoto, Japan
| | - Toru Fujiwara
- Department of Applied Biological Chemistry, Graduate School of Agricultural and Life Sciences, The University of Tokyo, Tokyo, Japan
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Norizuki T, Minamino N, Sato M, Ueda T. Autophagy regulates plastid reorganization during spermatogenesis in the liverwort Marchantia polymorpha. Front Plant Sci 2023; 14:1101983. [PMID: 36844055 PMCID: PMC9947651 DOI: 10.3389/fpls.2023.1101983] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 11/18/2022] [Accepted: 01/23/2023] [Indexed: 06/18/2023]
Abstract
Autophagy is a highly conserved system that delivers cytoplasmic components to lysosomes/vacuoles. Plastids are also degraded through autophagy for nutrient recycling and quality control; however, the involvement of autophagic degradation of plastids in plant cellular differentiation remains unclear. Here, we investigated whether spermiogenesis, the differentiation of spermatids into spermatozoids, in the liverwort Marchantia polymorpha involves autophagic degradation of plastids. Spermatozoids of M. polymorpha possess one cylindrical plastid at the posterior end of the cell body. By fluorescently labeling and visualizing plastids, we detected dynamic morphological changes during spermiogenesis. We found that a portion of the plastid was degraded in the vacuole in an autophagy-dependent manner during spermiogenesis, and impaired autophagy resulted in defective morphological transformation and starch accumulation in the plastid. Furthermore, we found that autophagy was dispensable for the reduction in plastid number and plastid DNA elimination. These results demonstrate a critical but selective role of autophagy in plastid reorganization during spermiogenesis in M. polymorpha.
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Affiliation(s)
- Takuya Norizuki
- Division of Cellular Dynamics, National Institute for Basic Biology, Okazaki, Japan
- Laboratory of Molecular Membrane Biology, Institute for Molecular and Cellular Regulation, Gunma University, Maebashi, Japan
| | - Naoki Minamino
- Division of Cellular Dynamics, National Institute for Basic Biology, Okazaki, Japan
| | - Miyuki Sato
- Laboratory of Molecular Membrane Biology, Institute for Molecular and Cellular Regulation, Gunma University, Maebashi, Japan
| | - Takashi Ueda
- Division of Cellular Dynamics, National Institute for Basic Biology, Okazaki, Japan
- Department of Basic Biology, SOKENDAI (The Graduate University for Advanced Studies), Okazaki, Japan
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