The modified flavonol glycosylation profile in the Arabidopsis rol1 mutants results in alterations in plant growth and cell shape formation.
Flavonoids are secondary metabolites known to modulate plant growth and development. A primary function of flavonols, a subgroup of flavonoids, is thought to be the modification of auxin fluxes in the plant. Flavonols in the cell are glycosylated, and the repressor of lrx1 (rol1) mutants of Arabidopsis thaliana, affected in rhamnose biosynthesis, have a modified flavonol glycosylation profile. A detailed analysis of the rol1-2 allele revealed hyponastic growth, aberrant pavement cell and stomatal morphology in cotyledons, and defective trichome formation. Blocking flavonoid biosynthesis suppresses the rol1-2 shoot phenotype, suggesting that it is induced by the modified flavonol profile. The hyponastic cotyledons of rol1-2 are likely to be the result of a flavonol-induced increase in auxin concentration. By contrast, the pavement cell, stomata, and trichome formation phenotypes appear not to be induced by the modified auxin distribution. Together, these results suggest that changes in the composition of flavonols can have a tremendous impact on plant development through both auxin-induced and auxin-independent processes.
Institute of Plant Biology, University of Zürich, 8008 Zurich, Switzerland. chringli@botinst.uzh.ch
Christoph
C
Ringli
Laurent
L
Bigler
Benjamin M
BM
Kuhn
Ruth-Maria
RM
Leiber
Anouck
A
Diet
Diana
D
Santelia
Beat
B
Frey
Stephan
S
Pollmann
Markus
M
Klein
D017360:Arabidopsis / Q000235:genetics* / Q000254:growth & development / Q000378:metabolism; D029681:Arabidopsis Proteins / Q000235:genetics* / Q000378:metabolism / Q000502:physiology; D048430:Cell Shape; D018548:Cotyledon / Q000235:genetics / Q000254:growth & development / Q000378:metabolism; D044948:Flavonols / Q000378:metabolism*; D018507:Gene Expression Regulation, Developmental; D018506:Gene Expression Regulation, Plant; D005816:Genetic Complementation Test; D005964:Glucosyltransferases / Q000235:genetics* / Q000378:metabolism / Q000502:physiology; D006031:Glycosylation; D007210:Indoleacetic Acids / Q000378:metabolism; D008954:Models, Biological; D009154:Mutation; D018517:Plant Roots / Q000166:cytology / Q000235:genetics / Q000378:metabolism; D018520:Plant Shoots / Q000235:genetics / Q000254:growth & development / Q000378:metabolism; D030821:Plants, Genetically Modified / Q000235:genetics / Q000254:growth & development / Q000378:metabolism
D029681:Arabidopsis Proteins; D044948:Flavonols; D007210:Indoleacetic Acids; D005964:Glucosyltransferases; C519657:RHM1 protein, Arabidopsis