Transcription Factor Interplay between LEAFY and APETALA1/CAULIFLOWER during Floral Initiation

Goslin, Kevin; Zheng, Beibei; Serrano-Mislata, Antonio; Rae, Liina; Ryan, Patrick T.; Kwaśniewska, Kamila; Thomson, Bennett; Ó’Maoiléidigh, Diarmuid S.; Madueño, Francisco; Wellmer, Frank; Graciet, Emmanuelle

doi:10.1104/pp.17.00098

Cited by 92 publications

(91 citation statements)

References 47 publications

(87 reference statements)

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Although LFY alone is sufficient to activate AP1 78, 79 , accumulation of this floral commitment factor is delayed relative LFY activity. Under floral inductive conditions in inflorescences AP1 upregulation occurs two to three days after that of LFY 52, 80, 81 . The delay in AP1 upregulation is of biological significance as it enables formation of branches prior to the irreversible switch to flower fate 52 .…”

Section: Discussionmentioning

confidence: 99%

LEAFY is a pioneer transcription factor and licenses cell reprogramming to floral fate

Jin

Klasfeld

García

et al. 2020

Preprint

View full text Add to dashboard Cite

Master transcription factors reprogram cell fate in multicellular eukaryotes. Pioneer transcription factors have prominent roles in this process because of their ability to contact their cognate binding motifs in closed chromatin. Reprogramming is pervasive in plants, whose development is plastic and tuned by the environment, yet no bonafide pioneer transcription factor has -been identified in this kingdom. Here we show that the master transcription factor LEAFY (LFY), which promotes floral fate through upregulation of the floral commitment factor APETALA1 (AP1), is a pioneer transcription factor. In vitro, LFY binds in a sequence-specific manner and with high affinity to the endogenous AP1 target locus DNA assembled into a nucleosome. In vivo, LFY associates with nucleosome occupied binding sites at the majority of its target loci, including AP1, where it co-occupies DNA with histones. Moreover, the LFY DNA contact helix shares defining properties with those of strong nucleosome binding pioneer factors. At the AP1 locus, LFY unlocks chromatin locally by displacing the H1 linker histone and by recruiting SWI/SNF chromatin remodelers, but broad changes in chromatin accessibility occur later and require activity of additional, non-pioneer transcription, factors. Our study provides a mechanistic framework for patterning of inflorescence architecture and uncovers striking similarities between plant and animal pioneer transcription factors. Further analyses aimed at elucidating the defining characteristics of pioneer transcription factors will allow harnessing these for enhanced cell fate reprogramming.Chromatin prevents expression of inappropriate or detrimental gene expression programs, allowing formation of distinct cell types from the same genome 1. The basic unit of chromatin is the nucleosome comprised of 150 base-pairs of DNA wrapped nearly two turns around the histone octamer 2. Chromatin is further compacted by nucleosome/nucleosome interactions and by the linker histone H1, which associates with the dyad (midpoint) of the nucleosome 3. During cell fate reprogramming in eukaryotes, master transcription factors silence and activate new gene expression programs in the context of chromatin 4-6. While it is easy to imagine how master transcription factors bind to active genes in open chromatin to trigger silencing, it is difficult to envision how these sequence-specific binding proteins can access their cognate motifs in silent chromatin to activate gene expression. This is because nucleosomes are refractory for most transcription factor binding 7-10 11. However, a special class of transcription factors, termed pioneer transcription factors, can access their cognate binding motifs in the nucleosome 1,4,12-17. These pioneer transcription factors play important roles in cell fate reprogramming. For example, the mammalian pioneer transcription factor FoxA reprograms fibroblast to hepatocytes 16,18-20, while the Oct4, Klf4 and Sox2 pioneer transcription factors reprogram fibroblasts to induced pluripotent stem ...

show abstract

Section: Discussionmentioning

confidence: 99%

LEAFY is a pioneer transcription factor and licenses cell reprogramming to floral fate

Jin

Klasfeld

García

et al. 2020

Preprint

View full text Add to dashboard Cite

show abstract

“…Other related MADS box proteins, such as CAULIFLOWER (CAL) and FRUITFULL (FUL) also promote determinacy (Ferrandiz et al 2000). In addition, consistent with its role in floral commitment, AP1 directly silences TFL1 with assistance from the SEPALLATA family transcription factor SEP4 (Ferrandiz et al 2000;Kaufmann et al 2010;Liu et al 2013;Serrano-Mislata et al 2016;Goslin et al 2017). Because of its role in the switch to reproductive development (inflores-cence formation), the role of FT in promoting floral fate is difficult to assess (Yamaguchi et al 2014).…”

Section: Axillary Meristems That Give Rise To Branches or Flowersmentioning

confidence: 95%

Plant Inflorescence Architecture: The Formation, Activity, and Fate of Axillary Meristems

Zhu

Wagner

2019

Cold Spring Harb Perspect Biol

View full text Add to dashboard Cite

The above-ground plant body in different plant species can have very distinct forms or architectures that arise by recurrent redeployment of a finite set of building blocks-leaves with axillary meristems, stems or branches, and flowers. The unique architectures of plant inflorescences in different plant families and species, on which this review focuses, determine the reproductive success and yield of wild and cultivated plants. Major contributors to the inflorescence architecture are the activity and developmental trajectories adopted by axillary meristems, which determine the degree of branching and the number of flowers formed. Recent advances in genetic and molecular analyses in diverse flowering plants have uncovered both common regulatory principles and unique players and/or regulatory interactions that underlie inflorescence architecture. Modulating activity of these regulators has already led to yield increases in the field. Additional insight into the underlying regulatory interactions and principles will not only uncover how their rewiring resulted in altered plant form, but will also enhance efforts at optimizing plant architecture in desirable ways in crop species.

show abstract

“…The onset of flower development in Arabidopsis is controlled by the interplay between LEAFY (LFY), APETALA1 (AP1) and its paralog CAULIFLOWER (CAL) [24]. We have already shown that garlic homolog of LFY (gaLFY) acts as a key-gene in the floral transition, as well as in inflorescence and flower differentiation [77].…”

Section: Gene Co-expressing During Meristem Transitionmentioning

confidence: 99%

Crosstalk in the darkness: bulb vernalization activates meristem transition via circadian rhythm and photoperiodic pathway

et al. 2020

View full text Add to dashboard Cite

Background: Geophytes possess specialized storage organs -bulbs, tubers, corms or rhizomes, which allow their survival during unfovarable periods and provide energy support for sprouting and sexual and vegetative reproduction. Bulbing and flowering of the geophyte depend on the combined effects of the internal and external factors, especially temperature and photoperiod. Many geophytes are extensively used in agriculture, but mechanisms of regulation of their flowering and bulbing are still unclear. Results: Comparative morpho-physiological and transcriptome analyses and quantitative validation of gene expression shed light on the molecular regulation of the responses to vernalization in garlic, a typical bulbous plant. Long dark cold exposure of bulbs is a major cue for flowering and bulbing, and its interactions with the genetic makeup of the individual plant dictate the phenotypic expression during growth stage. Photoperiod signal is not involved in the initial nuclear and metabolic processes, but might play role in the later stages of development, flower stem elongation and bulbing. Vernalization for 12 weeks at 4°C and planting in November resulted in flower initiation under short photoperiod in December-January, and early blooming and bulbing. In contrast, non-vernalized plants did not undergo meristem transition. Comparisons between vernalized and non-vernalized bulbs revealed~14,000 differentially expressed genes.Conclusions: Low temperatures stimulate a large cascades of molecular mechanisms in garlic, and a variety of flowering pathways operate together for the benefit of meristem transition, annual life cycle and viable reproduction results.The circadian clock appears to play a central role in the transition of the meristem from vegetative to reproductive stage in bulbous plant, serving as integrator of the low-temperature signals and the expression of the genes associated with vernalization, photoperiod and meristem transition. The reserved photoperiodic pathway is integrated at an upstream point, possibly by the same receptors. Therefore, in bulb, low temperatures stimulate cascades of developmental mechanisms, and several genetic flowering pathways intermix to achieve successful sexual and vegetative reproduction.

show abstract

Transcription Factor Interplay between LEAFY and APETALA1/CAULIFLOWER during Floral Initiation

Cited by 92 publications

References 47 publications

LEAFY is a pioneer transcription factor and licenses cell reprogramming to floral fate

LEAFY is a pioneer transcription factor and licenses cell reprogramming to floral fate

Plant Inflorescence Architecture: The Formation, Activity, and Fate of Axillary Meristems

Crosstalk in the darkness: bulb vernalization activates meristem transition via circadian rhythm and photoperiodic pathway

Contact Info

Product

Resources

About