CTP Synthase 2 From Arabidopsis thaliana Is Required for Complete Embryo Development
Pyrimidine de novo synthesis is an essential pathway in all organisms. The final and rate-limiting step in the synthesis of the nucleotide cytidine triphosphate (CTP) is catalyzed by CTP synthase (CTPS), and Arabidopsis harbors five isoforms. Single mutant lines defective in each one of the four iso...
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| Format: | Article |
| Language: | English |
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Frontiers Media S.A.
2021-04-01
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| Series: | Frontiers in Plant Science |
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| Online Access: | https://www.frontiersin.org/articles/10.3389/fpls.2021.652434/full |
| _version_ | 1828966951231160320 |
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| author | Daniel Hickl David Scheuring Torsten Möhlmann |
| author_facet | Daniel Hickl David Scheuring Torsten Möhlmann |
| author_sort | Daniel Hickl |
| collection | DOAJ |
| description | Pyrimidine de novo synthesis is an essential pathway in all organisms. The final and rate-limiting step in the synthesis of the nucleotide cytidine triphosphate (CTP) is catalyzed by CTP synthase (CTPS), and Arabidopsis harbors five isoforms. Single mutant lines defective in each one of the four isoforms do not show apparent phenotypical alterations in comparison to wild-type plants. However, Arabidopsis lines that contain T-DNA insertions in the CTPS2 gene were unable to produce homozygous offspring. Here, we show that CTPS2 exhibits a distinct expression pattern throughout embryo development, and loss-of-function mutants are embryo lethal, as siliques from +/ctps2 plants contained nearly 25% aborted seeds. This phenotype was rescued by complementation with CTPS2 under control of its endogenous promoter. CTPS2::GFP lines revealed expression only in the tip of columella cells in embryo root tips of the heart and later stages. Furthermore, CTPS2 expression in mature roots, most pronounced in the columella cells, shoots, and vasculature tissue of young seedlings, was observed. Filial generations of +/ctps2 plants did not germinate properly, even under external cytidine supply. During embryo development, the CTPS2 expression pattern resembled the established auxin reporter DR5::GFP. Indeed, the cloned promoter region we used in this study possesses a repeat of an auxin response element, and auxin supply increased CTPS2 expression in a cell-type-specific manner. Thus, we conclude that CTPS2 is essential for CTP supply in developing embryos, and loss-of-function mutants in CTPS2 are embryo lethal. |
| first_indexed | 2024-12-14T11:41:56Z |
| format | Article |
| id | doaj.art-3129b458ee0f4d8eb4493a78de7f3f65 |
| institution | Directory Open Access Journal |
| issn | 1664-462X |
| language | English |
| last_indexed | 2024-12-14T11:41:56Z |
| publishDate | 2021-04-01 |
| publisher | Frontiers Media S.A. |
| record_format | Article |
| series | Frontiers in Plant Science |
| spelling | doaj.art-3129b458ee0f4d8eb4493a78de7f3f652022-12-21T23:02:47ZengFrontiers Media S.A.Frontiers in Plant Science1664-462X2021-04-011210.3389/fpls.2021.652434652434CTP Synthase 2 From Arabidopsis thaliana Is Required for Complete Embryo DevelopmentDaniel Hickl0David Scheuring1Torsten Möhlmann2Plant Physiology, University of Kaiserslautern, Kaiserslautern, GermanyPlant Pathology, University of Kaiserslautern, Kaiserslautern, GermanyPlant Physiology, University of Kaiserslautern, Kaiserslautern, GermanyPyrimidine de novo synthesis is an essential pathway in all organisms. The final and rate-limiting step in the synthesis of the nucleotide cytidine triphosphate (CTP) is catalyzed by CTP synthase (CTPS), and Arabidopsis harbors five isoforms. Single mutant lines defective in each one of the four isoforms do not show apparent phenotypical alterations in comparison to wild-type plants. However, Arabidopsis lines that contain T-DNA insertions in the CTPS2 gene were unable to produce homozygous offspring. Here, we show that CTPS2 exhibits a distinct expression pattern throughout embryo development, and loss-of-function mutants are embryo lethal, as siliques from +/ctps2 plants contained nearly 25% aborted seeds. This phenotype was rescued by complementation with CTPS2 under control of its endogenous promoter. CTPS2::GFP lines revealed expression only in the tip of columella cells in embryo root tips of the heart and later stages. Furthermore, CTPS2 expression in mature roots, most pronounced in the columella cells, shoots, and vasculature tissue of young seedlings, was observed. Filial generations of +/ctps2 plants did not germinate properly, even under external cytidine supply. During embryo development, the CTPS2 expression pattern resembled the established auxin reporter DR5::GFP. Indeed, the cloned promoter region we used in this study possesses a repeat of an auxin response element, and auxin supply increased CTPS2 expression in a cell-type-specific manner. Thus, we conclude that CTPS2 is essential for CTP supply in developing embryos, and loss-of-function mutants in CTPS2 are embryo lethal.https://www.frontiersin.org/articles/10.3389/fpls.2021.652434/fullArabidopsisnucleotidesde novo synthesisCTP synthaseembryo development |
| spellingShingle | Daniel Hickl David Scheuring Torsten Möhlmann CTP Synthase 2 From Arabidopsis thaliana Is Required for Complete Embryo Development Frontiers in Plant Science Arabidopsis nucleotides de novo synthesis CTP synthase embryo development |
| title | CTP Synthase 2 From Arabidopsis thaliana Is Required for Complete Embryo Development |
| title_full | CTP Synthase 2 From Arabidopsis thaliana Is Required for Complete Embryo Development |
| title_fullStr | CTP Synthase 2 From Arabidopsis thaliana Is Required for Complete Embryo Development |
| title_full_unstemmed | CTP Synthase 2 From Arabidopsis thaliana Is Required for Complete Embryo Development |
| title_short | CTP Synthase 2 From Arabidopsis thaliana Is Required for Complete Embryo Development |
| title_sort | ctp synthase 2 from arabidopsis thaliana is required for complete embryo development |
| topic | Arabidopsis nucleotides de novo synthesis CTP synthase embryo development |
| url | https://www.frontiersin.org/articles/10.3389/fpls.2021.652434/full |
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