Asymmetric leaf development and blade expansion in Arabidopsis are mediated by KANADI and YABBY activities.
Asymmetric development of plant lateral organs is initiated by a partitioning of organ primordia into distinct domains along their adaxial/abaxial axis. Two primary determinants of abaxial cell fate are members of the KANADI and YABBY gene families. Progressive loss of KANADI activity in loss-of-function mutants results in progressive transformation of abaxial cell types into adaxial ones and a correlated loss of lamina formation. Novel, localized planes of blade expansion occur in some kanadi loss-of-function genotypes and these ectopic lamina outgrowths are YABBY dependent. We propose that the initial asymmetric leaf development is regulated primarily by mutual antagonism between KANADI and PHB-like genes, which is translated into polar YABBY expression. Subsequently, polar YABBY expression contributes both to abaxial cell fate and to abaxial/adaxial juxtaposition-mediated lamina expansion.
Eshed
Yuval
Y
Section of Plant Biology, Division of Biological Sciences, University of California, One Shields Avenue, Davis, CA 95616, USA.
Izhaki
Anat
A
Baum
Stuart F
SF
Floyd
Sandra K
SK
Bowman
John L
JL
D017360:Arabidopsis / Q000235:genetics / Q000254:growth & development*; D029681:Arabidopsis Proteins / Q000235:genetics / Q000378:metabolism*; D019656:Loss of Heterozygosity; D016296:Mutagenesis; D018515:Plant Leaves / Q000235:genetics / Q000254:growth & development*; D018547:Plant Stems / Q000235:genetics / Q000254:growth & development; D014157:Transcription Factors / Q000235:genetics / Q000378:metabolism*
D029681:Arabidopsis Proteins; C430846:KANADI protein, Arabidopsis; D014157:Transcription Factors; C121842:YABBY3 protein, Arabidopsis