Allocation of Heme is Differentially Regulated by Ferrochelatase Isoforms in Arabidopsis Cells
Heme is involved in various biological processes as a cofactor of hemoproteins located in various organelles. In plant cells, heme is synthesized by two isoforms of plastid-localized ferrochelatase, FC1 and FC2. In this study, by characterizing Arabidopsis T-DNA insertional mutants, we showed that t...
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| Format: | Article |
| Language: | English |
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Frontiers Media S.A.
2016-08-01
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| Series: | Frontiers in Plant Science |
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| Online Access: | http://journal.frontiersin.org/Journal/10.3389/fpls.2016.01326/full |
| _version_ | 1819229877120794624 |
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| author | Nino Asuela Espinas Nino Asuela Espinas Koichi Kobayashi Yasushi Sato Nobuyoshi Mochizuki Kaori Takahashi Ryouichi Tanaka Tatsuru Masuda |
| author_facet | Nino Asuela Espinas Nino Asuela Espinas Koichi Kobayashi Yasushi Sato Nobuyoshi Mochizuki Kaori Takahashi Ryouichi Tanaka Tatsuru Masuda |
| author_sort | Nino Asuela Espinas |
| collection | DOAJ |
| description | Heme is involved in various biological processes as a cofactor of hemoproteins located in various organelles. In plant cells, heme is synthesized by two isoforms of plastid-localized ferrochelatase, FC1 and FC2. In this study, by characterizing Arabidopsis T-DNA insertional mutants, we showed that the allocation of heme is differentially regulated by ferrochelatase isoforms in plant cells. Analyses of weak (fc1-1) and null (fc1-2) mutants suggest that FC1-producing heme is required for initial growth of seedling development. In contrast, weak (fc2-1) and null (fc2-2) mutants of FC2 showed pale green leaves and retarded growth, indicating that FC2-producing heme is necessary for chloroplast development. During the initial growth stage, FC2 deficiency caused reduction of plastid cytochromes. In addition, although FC2 deficiency marginally affected the assembly of photosynthetic reaction center complexes, it caused relatively larger but insufficient light-harvesting antenna to reaction centers, resulting in lower efficiency of photosynthesis. In the later vegetative growth, however, fc2-2 recovered photosynthetic growth, showing that FC1-producing heme may complement the FC2 deficiency. On the other hand, reduced level of cytochromes in microsomal fraction was discovered in fc1-1, suggesting that FC1-producing heme is mainly allocated to extraplastidic organelles. Furthermore, the expression of FC1 is induced by the treatment of an elicitor flg22 while that of FC2 was reduced, and fc1-1 abolished the flg22-dependent induction of FC1 expression and peroxidase activity. Consequently, our results clarified that FC2 produces heme for the photosynthetic machinery in the chloroplast, while FC1 is the housekeeping enzyme providing heme cofactor to the entire cell. In addition, FC1 can partly complement FC2 deficiency and is also involved in defense against stressful conditions. |
| first_indexed | 2024-12-23T11:20:09Z |
| format | Article |
| id | doaj.art-147d65bad4dc4632b9a5c6732df52b9f |
| institution | Directory Open Access Journal |
| issn | 1664-462X |
| language | English |
| last_indexed | 2024-12-23T11:20:09Z |
| publishDate | 2016-08-01 |
| publisher | Frontiers Media S.A. |
| record_format | Article |
| series | Frontiers in Plant Science |
| spelling | doaj.art-147d65bad4dc4632b9a5c6732df52b9f2022-12-21T17:49:06ZengFrontiers Media S.A.Frontiers in Plant Science1664-462X2016-08-01710.3389/fpls.2016.01326212725Allocation of Heme is Differentially Regulated by Ferrochelatase Isoforms in Arabidopsis CellsNino Asuela Espinas0Nino Asuela Espinas1Koichi Kobayashi2Yasushi Sato3Nobuyoshi Mochizuki4Kaori Takahashi5Ryouichi Tanaka6Tatsuru Masuda7The University of TokyoOkinawa Institute of Science and Technology Graduate UniversityThe University of TokyoEhime UniversityKyoto UniversityHokkaido UniversityHokkaido UniversityThe University of TokyoHeme is involved in various biological processes as a cofactor of hemoproteins located in various organelles. In plant cells, heme is synthesized by two isoforms of plastid-localized ferrochelatase, FC1 and FC2. In this study, by characterizing Arabidopsis T-DNA insertional mutants, we showed that the allocation of heme is differentially regulated by ferrochelatase isoforms in plant cells. Analyses of weak (fc1-1) and null (fc1-2) mutants suggest that FC1-producing heme is required for initial growth of seedling development. In contrast, weak (fc2-1) and null (fc2-2) mutants of FC2 showed pale green leaves and retarded growth, indicating that FC2-producing heme is necessary for chloroplast development. During the initial growth stage, FC2 deficiency caused reduction of plastid cytochromes. In addition, although FC2 deficiency marginally affected the assembly of photosynthetic reaction center complexes, it caused relatively larger but insufficient light-harvesting antenna to reaction centers, resulting in lower efficiency of photosynthesis. In the later vegetative growth, however, fc2-2 recovered photosynthetic growth, showing that FC1-producing heme may complement the FC2 deficiency. On the other hand, reduced level of cytochromes in microsomal fraction was discovered in fc1-1, suggesting that FC1-producing heme is mainly allocated to extraplastidic organelles. Furthermore, the expression of FC1 is induced by the treatment of an elicitor flg22 while that of FC2 was reduced, and fc1-1 abolished the flg22-dependent induction of FC1 expression and peroxidase activity. Consequently, our results clarified that FC2 produces heme for the photosynthetic machinery in the chloroplast, while FC1 is the housekeeping enzyme providing heme cofactor to the entire cell. In addition, FC1 can partly complement FC2 deficiency and is also involved in defense against stressful conditions.http://journal.frontiersin.org/Journal/10.3389/fpls.2016.01326/fullCytochromesFerrochelatasePhotosynthesisbiotic stressplastidheme allocation |
| spellingShingle | Nino Asuela Espinas Nino Asuela Espinas Koichi Kobayashi Yasushi Sato Nobuyoshi Mochizuki Kaori Takahashi Ryouichi Tanaka Tatsuru Masuda Allocation of Heme is Differentially Regulated by Ferrochelatase Isoforms in Arabidopsis Cells Frontiers in Plant Science Cytochromes Ferrochelatase Photosynthesis biotic stress plastid heme allocation |
| title | Allocation of Heme is Differentially Regulated by Ferrochelatase Isoforms in Arabidopsis Cells |
| title_full | Allocation of Heme is Differentially Regulated by Ferrochelatase Isoforms in Arabidopsis Cells |
| title_fullStr | Allocation of Heme is Differentially Regulated by Ferrochelatase Isoforms in Arabidopsis Cells |
| title_full_unstemmed | Allocation of Heme is Differentially Regulated by Ferrochelatase Isoforms in Arabidopsis Cells |
| title_short | Allocation of Heme is Differentially Regulated by Ferrochelatase Isoforms in Arabidopsis Cells |
| title_sort | allocation of heme is differentially regulated by ferrochelatase isoforms in arabidopsis cells |
| topic | Cytochromes Ferrochelatase Photosynthesis biotic stress plastid heme allocation |
| url | http://journal.frontiersin.org/Journal/10.3389/fpls.2016.01326/full |
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