Transcriptional diversification and functional conservation between DELLA proteins in Arabidopsis.
Plasticity and robustness of signaling pathways partly rely on genetic redundancy, although the precise mechanism that provides functional specificity to the different redundant elements in a given process is often unknown. In Arabidopsis, functional redundancy in gibberellin signaling has been largely attributed to the presence of five members of the DELLA family of transcriptional regulators. Here, we demonstrate that two evolutionarily and functionally divergent DELLA proteins, RGL2 and RGA, can perform exchangeable functions when they are expressed under control of the reciprocal promoter. Furthermore, both DELLA proteins display equivalent abilities to interact with PIF4 and with other bHLH transcription factors with a reported role in the control of cell growth and seed germination. Therefore, we propose that functional diversification of Arabidopsis DELLA proteins has largely relied on changes in their gene expression patterns rather than on their ability to interact with different regulatory partners, model also supported by a clustering analysis of DELLA transcript profiles over a range of organs and growth conditions that revealed specific patterns of expression for each of these genes.
Gallego-Bartolomé
Javier
J
Instituto de Biología Molecular y Celular de Plantas (UPV-Consejo Superior de Investigaciones Científicas), Universidad Politécnica de Valencia, Valencia, Spain.
Minguet
Eugenio G
EG
Marín
Jaime A
JA
Prat
Salomé
S
Blázquez
Miguel A
MA
Alabadí
David
D
D017360:Arabidopsis / Q000235:genetics* / Q000254:growth & development / Q000378:metabolism; D029681:Arabidopsis Proteins / Q000235:genetics* / Q000378:metabolism; D015153:Blotting, Western; D016000:Cluster Analysis; D020440:Gene Duplication; D017343:Genes, Plant / Q000235:genetics; D009154:Mutation; D010802:Phylogeny; D030821:Plants, Genetically Modified / Q000235:genetics / Q000378:metabolism; D012097:Repressor Proteins / Q000235:genetics* / Q000378:metabolism; D015398:Signal Transduction; D014157:Transcription Factors / Q000235:genetics* / Q000378:metabolism; D014158:Transcription, Genetic
D029681:Arabidopsis Proteins; C508468:RGA protein, Arabidopsis; C450823:RGL2 protein, Arabidopsis; D012097:Repressor Proteins; D014157:Transcription Factors