Journal
JOURNAL OF EXPERIMENTAL BOTANY
Volume 65, Issue 20, Pages 5811-5822Publisher
OXFORD UNIV PRESS
DOI: 10.1093/jxb/eru317
Keywords
Arabidopsis; circadian clock; flowering time control; photoperiod; repressors; SRR1
Categories
Funding
- Alexander-von-Humboldt foundation
- DFG [SPP1530]
Ask authors/readers for more resources
Timing of flowering is determined by environmental and developmental signals, leading to promotion or repression of key floral integrators. SENSITIVITY TO RED LIGHT REDUCED (SRR1) is a pioneer protein previously shown to be involved in regulation of the circadian clock and phytochrome B signalling in Arabidopsis thaliana. This report has examined the role of SRR1 in flowering time control. Loss-of-function srr1-1 plants flowered very early compared with the wild type under short-day conditions and had a weak flowering response to increasing daylength. Furthermore, FLOWERING LOCUS T (FT) transcript levels were elevated already in short days in srr1-1 compared with the wild type. This correlated with elevated end of day levels of CONSTANS (CO), whereas levels of CYCLING DOF FACTOR 1 (CDF1), a repressor of CO transcription, were reduced. srr1-1 gi-2 and srr1-1 co-9 double mutants showed that SRR1 can also repress flowering independently of the photoperiodic pathway. srr1-1 flowered consistently early between 16 degrees C and 27 degrees C, showing that SRR1 prevents premature flowering over a wide temperature range. SRR1 also promotes expression of the repressors TEMPRANILLO 1 (TEM1) and TEM2. Consequently their targets in the gibberellin biosynthesis pathway were elevated in srr1-1. SRR1 is thus an important focal point of both photoperiodic and photoperiod-independent regulation of flowering. By stimulating expression of the FT-binding repressors CDF1, TEM1 and TEM2, and FLC, flowering is inhibited in non-inductive conditions.
Authors
I am an author on this paper
Click your name to claim this paper and add it to your profile.
Reviews
Recommended
No Data Available