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A Point Mutation in Phytochromobilin synthase Alters the Circadian Clock and Photoperiodic Flowering of Medicago truncatula

Plants use seasonal cues to initiate flowering at an appropriate time of year to ensure optimal reproductive success. The circadian clock integrates these daily and seasonal cues with internal cues to initiate flowering. The molecular pathways that control the sensitivity of flowering to photoperiod...

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Autores principales: Perez-Santangelo, Soledad, Napier, Nathanael, Robson, Fran, Weller, James L., Bond, Donna M., Macknight, Richard C.
Formato: Online Artículo Texto
Lenguaje:English
Publicado: MDPI 2022
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8839385/
https://www.ncbi.nlm.nih.gov/pubmed/35161220
http://dx.doi.org/10.3390/plants11030239
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author Perez-Santangelo, Soledad
Napier, Nathanael
Robson, Fran
Weller, James L.
Bond, Donna M.
Macknight, Richard C.
author_facet Perez-Santangelo, Soledad
Napier, Nathanael
Robson, Fran
Weller, James L.
Bond, Donna M.
Macknight, Richard C.
author_sort Perez-Santangelo, Soledad
collection PubMed
description Plants use seasonal cues to initiate flowering at an appropriate time of year to ensure optimal reproductive success. The circadian clock integrates these daily and seasonal cues with internal cues to initiate flowering. The molecular pathways that control the sensitivity of flowering to photoperiods (daylengths) are well described in the model plant Arabidopsis. However, much less is known for crop species, such as legumes. Here, we performed a flowering time screen of a TILLING population of Medicago truncatula and found a line with late-flowering and altered light-sensing phenotypes. Using RNA sequencing, we identified a nonsense mutation in the Phytochromobilin synthase (MtPΦBS) gene, which encodes an enzyme that carries out the final step in the biosynthesis of the chromophore required for phytochrome (phy) activity. The analysis of the circadian clock in the MtpΦbs mutant revealed a shorter circadian period, which was shared with the MtphyA mutant. The MtpΦbs and MtphyA mutants showed downregulation of the FT floral regulators MtFTa1 and MtFTb1/b2 and a change in phase for morning and night core clock genes. Our findings show that phyA is necessary to synchronize the circadian clock and integration of light signalling to precisely control the timing of flowering.
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spelling pubmed-88393852022-02-13 A Point Mutation in Phytochromobilin synthase Alters the Circadian Clock and Photoperiodic Flowering of Medicago truncatula Perez-Santangelo, Soledad Napier, Nathanael Robson, Fran Weller, James L. Bond, Donna M. Macknight, Richard C. Plants (Basel) Article Plants use seasonal cues to initiate flowering at an appropriate time of year to ensure optimal reproductive success. The circadian clock integrates these daily and seasonal cues with internal cues to initiate flowering. The molecular pathways that control the sensitivity of flowering to photoperiods (daylengths) are well described in the model plant Arabidopsis. However, much less is known for crop species, such as legumes. Here, we performed a flowering time screen of a TILLING population of Medicago truncatula and found a line with late-flowering and altered light-sensing phenotypes. Using RNA sequencing, we identified a nonsense mutation in the Phytochromobilin synthase (MtPΦBS) gene, which encodes an enzyme that carries out the final step in the biosynthesis of the chromophore required for phytochrome (phy) activity. The analysis of the circadian clock in the MtpΦbs mutant revealed a shorter circadian period, which was shared with the MtphyA mutant. The MtpΦbs and MtphyA mutants showed downregulation of the FT floral regulators MtFTa1 and MtFTb1/b2 and a change in phase for morning and night core clock genes. Our findings show that phyA is necessary to synchronize the circadian clock and integration of light signalling to precisely control the timing of flowering. MDPI 2022-01-18 /pmc/articles/PMC8839385/ /pubmed/35161220 http://dx.doi.org/10.3390/plants11030239 Text en © 2022 by the authors. https://creativecommons.org/licenses/by/4.0/Licensee MDPI, Basel, Switzerland. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) license (https://creativecommons.org/licenses/by/4.0/).
spellingShingle Article
Perez-Santangelo, Soledad
Napier, Nathanael
Robson, Fran
Weller, James L.
Bond, Donna M.
Macknight, Richard C.
A Point Mutation in Phytochromobilin synthase Alters the Circadian Clock and Photoperiodic Flowering of Medicago truncatula
title A Point Mutation in Phytochromobilin synthase Alters the Circadian Clock and Photoperiodic Flowering of Medicago truncatula
title_full A Point Mutation in Phytochromobilin synthase Alters the Circadian Clock and Photoperiodic Flowering of Medicago truncatula
title_fullStr A Point Mutation in Phytochromobilin synthase Alters the Circadian Clock and Photoperiodic Flowering of Medicago truncatula
title_full_unstemmed A Point Mutation in Phytochromobilin synthase Alters the Circadian Clock and Photoperiodic Flowering of Medicago truncatula
title_short A Point Mutation in Phytochromobilin synthase Alters the Circadian Clock and Photoperiodic Flowering of Medicago truncatula
title_sort point mutation in phytochromobilin synthase alters the circadian clock and photoperiodic flowering of medicago truncatula
topic Article
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8839385/
https://www.ncbi.nlm.nih.gov/pubmed/35161220
http://dx.doi.org/10.3390/plants11030239
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