YABBYs and the transcriptional corepressors LEUNIG and LEUNIG_HOMOLOG maintain leaf polarity and meristem activity in Arabidopsis.
In Arabidopsis thaliana, FILAMENTOUS FLOWER (FIL) and YABBY3 (YAB3) encode YABBY domain proteins that regulate abaxial patterning, growth of lateral organs, and inflorescence phyllotaxy. In this study, we show that YABs physically interact with components of a transcriptional repressor complex that include LEUNIG (LUG), LEUNIG_HOMOLOG (LUH), the LUG-associated coregulator SEUSS, and related SEUSS-LIKE proteins. Consistent with the formation of a LUG-YAB complex, we find that lug mutants enhance the polarity and growth defects of fil yab3 mutant leaves and that this enhancement is due to a loss of LUG activity from the abaxial domain. We performed a more extensive genetic analysis, which included the characterization of yab triple and quadruple mutants, lug luh/+ (heterozygous only for luh) mutants, and plants expressing artificial microRNAs targeting LUG or LUH. These analyses showed that the LUG-YAB complex also promotes adaxial cell identity in leaves as well as embryonic shoot apical meristem (SAM) initiation and postembryonic SAM maintenance. Based on the likely formation of the LUG-YAB complex in the abaxial domain of cotyledons and leaves, we propose that this complex has numerous non-cell-autonomous functions during plant development.
Stahle
Melissa I
MI
Genetics Department, University of Melbourne, Parkville, VIC 3010, Australia.
Kuehlich
Janine
J
Staron
Lindsay
L
von Arnim
Albrecht G
AG
Golz
John F
JF
D017360:Arabidopsis / Q000235:genetics / Q000254:growth & development / Q000378:metabolism*; D029681:Arabidopsis Proteins / Q000235:genetics / Q000378:metabolism*; D018506:Gene Expression Regulation, Plant; D018519:Meristem / Q000235:genetics / Q000254:growth & development / Q000378:metabolism*; D008969:Molecular Sequence Data; D018515:Plant Leaves / Q000235:genetics / Q000254:growth & development / Q000378:metabolism*; D030821:Plants, Genetically Modified / Q000235:genetics / Q000254:growth & development / Q000378:metabolism; D011485:Protein Binding; D020133:Reverse Transcriptase Polymerase Chain Reaction; D014157:Transcription Factors / Q000235:genetics / Q000378:metabolism; D020798:Two-Hybrid System Techniques
C119103:AFO protein, Arabidopsis; D029681:Arabidopsis Proteins; C417768:LUG protein, Arabidopsis; D014157:Transcription Factors; C530966:YAB5 protein, Arabidopsis; C121842:YABBY3 protein, Arabidopsis