An evolutionarily conserved mechanism delimiting SHR movement defines a single layer of endodermis in plants.
Intercellular protein movement plays a critical role in animal and plant development. SHORTROOT (SHR) is a moving transcription factor essential for endodermis specification in the Arabidopsis root. Unlike diffusible animal morphogens, which form a gradient across multiple cell layers, SHR movement is limited to essentially one cell layer. However, the molecular mechanism is unknown. We show that SCARECROW (SCR) blocks SHR movement by sequestering it into the nucleus through protein-protein interaction and a safeguard mechanism that relies on a SHR/SCR-dependent positive feedback loop for SCR transcription. Our studies with SHR and SCR homologs from rice suggest that this mechanism is evolutionarily conserved, providing a plausible explanation why nearly all plants have a single layer of endodermis.
Cui
Hongchang
H
Department of Biology and Institute for Genome Sciences and Policy, Duke University, Durham, NC 27708, USA.
Levesque
Mitchell P
MP
Vernoux
Teva
T
Jung
Jee W
JW
Paquette
Alice J
AJ
Gallagher
Kimberly L
KL
Wang
Jean Y
JY
Blilou
Ikram
I
Scheres
Ben
B
Benfey
Philip N
PN
D017360:Arabidopsis / Q000166:cytology / Q000235:genetics / Q000254:growth & development / Q000378:metabolism*; D029681:Arabidopsis Proteins / Q000235:genetics / Q000378:metabolism*; D005075:Biological Evolution; D002467:Cell Nucleus / Q000378:metabolism; D025461:Feedback, Physiological; D015870:Gene Expression; D017343:Genes, Plant; D008954:Models, Biological; D020411:Oligonucleotide Array Sequence Analysis; D012275:Oryza / Q000235:genetics / Q000378:metabolism; D010940:Plant Proteins / Q000235:genetics / Q000378:metabolism; D018517:Plant Roots / Q000166:cytology* / Q000235:genetics / Q000254:growth & development / Q000378:metabolism*; D030821:Plants, Genetically Modified; D011401:Promoter Regions, Genetic; D011485:Protein Binding; D021381:Protein Transport; D011993:Recombinant Fusion Proteins / Q000378:metabolism; D014157:Transcription Factors / Q000235:genetics / Q000378:metabolism*; D014158:Transcription, Genetic
D029681:Arabidopsis Proteins; D010940:Plant Proteins; D011993:Recombinant Fusion Proteins; C100978:SCR protein, Arabidopsis; C410510:SHORT ROOT protein, Arabidopsis; D014157:Transcription Factors