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

Autor: Soledad Perez-Santangelo, Nathanael Napier, Fran Robson, James L. Weller, Donna M. Bond, Richard C. Macknight
Jazyk: angličtina
Rok vydání: 2022
Předmět:
Zdroj: Plants, Vol 11, Iss 3, p 239 (2022)
Druh dokumentu: article
ISSN: 2223-7747
DOI: 10.3390/plants11030239
Popis: 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.
Databáze: Directory of Open Access Journals