Unknown,Transcriptomics,Genomics,Proteomics

Dataset Information

PFT1, the MED25 subunit of the plant Mediator complex, promotes flowering through CONSTANS dependent and independent mechanisms in Arabidopsis

ABSTRACT: Two aspects of light are very important for plant development: the length of the light phase or photoperiod and the quality of incoming light. Photoperiod detection allows plants to anticipate the arrival of the next season, whereas light quality, mainly the red to far-red ratio (R:FR), is an early signal of competition by neighbouring plants. phyB represses flowering by antagonising CO at the transcriptional and post-translational levels. A low R:FR decreases active phyB and consequently increases active CO, which in turn activates the expression of FT, the plant florigen. Other phytochromes like phyD and phyE seem to have redundant roles with phyB. PFT1, the MED25 subunit of the plant Mediator complex, has been proposed to act in the light-quality pathway that regulates flowering time downstream of phyB. However, whether PFT1 signals through CO and its specific mechanism are unclear. Here we show that CO-dependent and -independent mechanisms operate downstream of phyB, phyD and phyE to promote flowering, and that PFT1 is equally able to promote flowering by modulating both CO-dependent and -independent pathways. Our data are consistent with the role of PFT1 as an activator of CO transcription, and also of FT transcription, in a CO-independent manner. Our transcriptome analysis is also consistent with CO and FT genes being the most important flowering targets of PFT1. Furthermore, comparison of the pft1 transcriptome with transcriptomes after fungal and herbivore attack strongly suggests that PFT1 acts as a hub, integrating a variety of interdependent environmental stimuli, including light quality and jasmonic acid-dependent defences. Two genotypes, WT (Columbia) and pft1-1 mutants. Three biological replicates for each condition (genotype X temperature combination). RNA prepared independently for each sample.

ORGANISM(S): Arabidopsis thaliana

SUBMITTER: Sabrina Iñigo

PROVIDER: E-GEOD-37014 | biostudies-arrayexpress |

REPOSITORIES: biostudies-arrayexpress

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Publications

PFT1, the MED25 subunit of the plant Mediator complex, promotes flowering through CONSTANS dependent and independent mechanisms in Arabidopsis.

Iñigo Sabrina S Alvarez Mariano J MJ Strasser Bárbara B Califano Andrea A Cerdán Pablo D PD

The Plant journal : for cell and molecular biology 20111116 4

Two aspects of light are very important for plant development: the length of the light phase or photoperiod and the quality of incoming light. Photoperiod detection allows plants to anticipate the arrival of the next season, whereas light quality, mainly the red to far-red ratio (R:FR), is an early signal of competition by neighbouring plants. phyB represses flowering by antagonising CO at the transcriptional and post-translational levels. A low R:FR decreases active phyB and consequently increa ...[more]

PMID: 21985558

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Project description:Plant growth and development are strongly affected by light signals perceived by phytochromes (phy) and cryptochromes (cry). The physical interaction between photoreceptors and the cross-talk among downstream signalling steps creates a network of interactions in which the action of one photoreceptor depends on the status of the others. The processes modulated by phy and or cry include seed germination, seedling de-etiolation, plant body formation and flowering. Compared to the wild type the leaves of the phyB mutant are characterised by their extended petioles and pale colour. These features resemble the phenotype of normal plants grown under the low red to far-red ratios typical of dense plant canopies thus providing support to the idea that phyB plays a key role in the perception of high red to far-red ratios. The triple mutant lacking phyA cry1 and cry2 shows little differences in leaf size and shape with the wild typebut the quadruple phyA phyB cry1 cry2 mutant shows severely impaired leaf expansion. In addition to the specific effects on leaf sizeshape and pigmentation the phyB mutation accelerates flowering in the wild type background. This effect can be observed as a reduced number of days between sowing and visible flower buds (time scale) and as a reduced final number of leaves (developmental scale). However in the phyA cry1 cry2 triple mutant background the phyB mutation accelerates flowering on a developmental scale but severely delays flowering on a time scale. The long photoperiods inducing flowering are perceived by the leaves. Flowering signals that could include hormones and sugars migrate from the leaves to the apex in response to the light stimulus. We propose to compare the following mRNA samples of expanding leaves: 1) wild type 2) phyB mutant 3) phyA cry1 cry2 triple mutant 4) phyA phyB cry1 cry2 quadruple mutant. The comparison between the wild type and the phyB mutant will help to uncover the changes in leaf mRNA patterns underlying enhanced petiole growthreduced pigmentation and early flowering in response to the absence of phyB activity. The comparison between the phyA cry1 cry2 triple mutant and the phyA phyB cry1 cry2 quadruple mutant should reveal the mRNA differences between photosynthetic leaves with dramatically different abilities to expand. The added value of the simultaneous analysis of the two comparisons is that effect of phyB is different in both genetic backgrounds and this should provide information on the mechanisms and significance of photoreceptor interactions.

Dataset Information

PFT1, the MED25 subunit of the plant Mediator complex, promotes flowering through CONSTANS dependent and independent mechanisms in Arabidopsis

Publications

PFT1, the MED25 subunit of the plant Mediator complex, promotes flowering through CONSTANS dependent and independent mechanisms in Arabidopsis.

Similar Datasets

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