A functional TOC complex contributes to gravity signal transduction in Arabidopsis
Although plastid sedimentation has long been recognized as important for a plant’s perception of gravity, it was recently shown that plastids play an additional function in gravitropism. The Translocon at the Outer envelope membrane of Chloroplasts (TOC) complex transports nuclear-encoded proteins i...
| Main Authors: | , , |
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| Format: | Article |
| Language: | English |
| Published: |
Frontiers Media S.A.
2014-04-01
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| Series: | Frontiers in Plant Science |
| Subjects: | |
| Online Access: | http://journal.frontiersin.org/Journal/10.3389/fpls.2014.00148/full |
| _version_ | 1818355648604143616 |
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| author | Allison Karen Strohm Greg A Barrett-Wilt Patrick H Masson |
| author_facet | Allison Karen Strohm Greg A Barrett-Wilt Patrick H Masson |
| author_sort | Allison Karen Strohm |
| collection | DOAJ |
| description | Although plastid sedimentation has long been recognized as important for a plant’s perception of gravity, it was recently shown that plastids play an additional function in gravitropism. The Translocon at the Outer envelope membrane of Chloroplasts (TOC) complex transports nuclear-encoded proteins into plastids, and a receptor of this complex, Toc132, was previously hypothesized to contribute to gravitropism either by directly functioning as a gravity signal transducer or by indirectly mediating the plastid localization of a gravity signal transducer. Here we show that mutations in multiple genes encoding TOC complex components affect gravitropism in a genetically sensitized background and that the cytoplasmic acidic domain of Toc132 is not required for its involvement in this process. Furthermore, mutations in Toc132 enhance the gravitropic defect of a mutant whose amyloplasts lack starch. Finally, we show that the levels of several nuclear-encoded root proteins are altered in toc132 mutants. These data suggest that the TOC complex indirectly mediates gravity signal transduction in Arabidopsis and support the idea that plastids are involved in gravitropism not only through their ability to sediment but also as part of the signal transduction mechanism. |
| first_indexed | 2024-12-13T19:44:40Z |
| format | Article |
| id | doaj.art-b0757f0717e04071a8e7da6b6e1fe230 |
| institution | Directory Open Access Journal |
| issn | 1664-462X |
| language | English |
| last_indexed | 2024-12-13T19:44:40Z |
| publishDate | 2014-04-01 |
| publisher | Frontiers Media S.A. |
| record_format | Article |
| series | Frontiers in Plant Science |
| spelling | doaj.art-b0757f0717e04071a8e7da6b6e1fe2302022-12-21T23:33:35ZengFrontiers Media S.A.Frontiers in Plant Science1664-462X2014-04-01510.3389/fpls.2014.0014881357A functional TOC complex contributes to gravity signal transduction in ArabidopsisAllison Karen Strohm0Greg A Barrett-Wilt1Patrick H Masson2University of Wisconsin-MadisonUniversity of Wisconsin-MadisonUniversity of Wisconsin-MadisonAlthough plastid sedimentation has long been recognized as important for a plant’s perception of gravity, it was recently shown that plastids play an additional function in gravitropism. The Translocon at the Outer envelope membrane of Chloroplasts (TOC) complex transports nuclear-encoded proteins into plastids, and a receptor of this complex, Toc132, was previously hypothesized to contribute to gravitropism either by directly functioning as a gravity signal transducer or by indirectly mediating the plastid localization of a gravity signal transducer. Here we show that mutations in multiple genes encoding TOC complex components affect gravitropism in a genetically sensitized background and that the cytoplasmic acidic domain of Toc132 is not required for its involvement in this process. Furthermore, mutations in Toc132 enhance the gravitropic defect of a mutant whose amyloplasts lack starch. Finally, we show that the levels of several nuclear-encoded root proteins are altered in toc132 mutants. These data suggest that the TOC complex indirectly mediates gravity signal transduction in Arabidopsis and support the idea that plastids are involved in gravitropism not only through their ability to sediment but also as part of the signal transduction mechanism.http://journal.frontiersin.org/Journal/10.3389/fpls.2014.00148/fullArabidopsisGravitropismSignal TransductionrootsplastidTOC complex |
| spellingShingle | Allison Karen Strohm Greg A Barrett-Wilt Patrick H Masson A functional TOC complex contributes to gravity signal transduction in Arabidopsis Frontiers in Plant Science Arabidopsis Gravitropism Signal Transduction roots plastid TOC complex |
| title | A functional TOC complex contributes to gravity signal transduction in Arabidopsis |
| title_full | A functional TOC complex contributes to gravity signal transduction in Arabidopsis |
| title_fullStr | A functional TOC complex contributes to gravity signal transduction in Arabidopsis |
| title_full_unstemmed | A functional TOC complex contributes to gravity signal transduction in Arabidopsis |
| title_short | A functional TOC complex contributes to gravity signal transduction in Arabidopsis |
| title_sort | functional toc complex contributes to gravity signal transduction in arabidopsis |
| topic | Arabidopsis Gravitropism Signal Transduction roots plastid TOC complex |
| url | http://journal.frontiersin.org/Journal/10.3389/fpls.2014.00148/full |
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