Temperature-dependent regulation of flowering by antagonistic FLM variants.
The appropriate timing of flowering is crucial for plant reproductive success. It is therefore not surprising that intricate genetic networks have evolved to perceive and integrate both endogenous and environmental signals, such as carbohydrate and hormonal status, photoperiod and temperature. In contrast to our detailed understanding of the vernalization pathway, little is known about how flowering time is controlled in response to changes in the ambient growth temperature. In Arabidopsis thaliana, the MADS-box transcription factor genes FLOWERING LOCUS M (FLM) and SHORT VEGETATIVE PHASE (SVP) have key roles in this process. FLM is subject to temperature-dependent alternative splicing. Here we report that the two main FLM protein splice variants, FLM-β and FLM-δ, compete for interaction with the floral repressor SVP. The SVP-FLM-β complex is predominately formed at low temperatures and prevents precocious flowering. By contrast, the competing SVP-FLM-δ complex is impaired in DNA binding and acts as a dominant-negative activator of flowering at higher temperatures. Our results show a new mechanism that controls the timing of the floral transition in response to changes in ambient temperature. A better understanding of how temperature controls the molecular mechanisms of flowering will be important to cope with current changes in global climate.
1] Max Planck Institute for Developmental Biology, Department of Molecular Biology, Spemannstr. 35, 72076 Tübingen, Germany [2] Instituto de Hortofruticultura Subtropical y Mediterránea, Universidad de Málaga-Consejo Superior de Investigaciones Científicas, Departamento de Biología Molecular y Bioquímica, Facultad de Ciencias, Universidad de Málaga, 29071 Málaga, Spain (D.P.); Department of Organismic and Evolutionary Biology, Harvard University, 16 Divinity Avenue, Cambridge, Massachusetts 02138, USA (L.Y.); Boyce Thompson Institute for Plant Research, Tower Road, Ithaca, New York 14853-1801, USA (J.M.).
David
D
Posé
Leonie
L
Verhage
Felix
F
Ott
Levi
L
Yant
Johannes
J
Mathieu
Gerco C
GC
Angenent
Richard G H
RG
Immink
Markus
M
Schmid
D017398:Alternative Splicing / Q000235:genetics*; D017360:Arabidopsis / Q000235:genetics / Q000502:physiology*; D029681:Arabidopsis Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D004268:DNA-Binding Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D035264:Flowers / Q000235:genetics / Q000502:physiology*; D018506:Gene Expression Regulation, Plant; D026161:MADS Domain Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D030821:Plants, Genetically Modified; D011485:Protein Binding; D020033:Protein Isoforms / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D013696:Temperature; D013997:Time Factors; D014157:Transcription Factors / Q000378:metabolism
D029681:Arabidopsis Proteins; D004268:DNA-Binding Proteins; C522476:FLM protein, Arabidopsis; D026161:MADS Domain Proteins; D020033:Protein Isoforms; C407549:SVP protein, Arabidopsis; D014157:Transcription Factors