US EPA

1495307 

Journal Article 

Flavonols Accumulate Asymmetrically and Affect Auxin Transport in Arabidopsis 

Kuhn, BM; Geisler, M; Bigler, L; Ringli, C 

2011 

1 

Plant Physiology
ISSN: 0032-0889
EISSN: 1532-2548 

156 

2 

585-595 

English 

21502189 

10.1104/pp.111.175976 

WOS:000291146800013 

https://www.scopus.com/inward/record.uri?eid=2-s2.0-79958038962&doi=10.1104%2fpp.111.175976&partnerID=40&md5=9aaf0ab06ac6782c4110d0dbae26abb0
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Flavonoids represent a class of secondary metabolites with
diverse functions in plants including ultraviolet protection, pathogen defense, and interspecies
communication. They are also known as modulators of signaling processes in plant and animal
systems and therefore are considered to have beneficial effects as nutraceuticals. The rol1-2
(for repressor of lrx1) mutation of Arabidopsis (Arabidopsis thaliana) induces aberrant
accumulation of flavonols and a cell-growth phenotype in the shoot. The hyponastic cotyledons,
aberrant shape of pavement cells, and deformed trichomes in rol1-2 mutants are suppressed by
blocking flavonoid biosynthesis, suggesting that the altered flavonol accumulation in these
plants induces the shoot phenotype. Indeed, the identification of several transparent testa, myb,
and fls1 (for flavonol synthase1) alleles in a rol1-2 suppressor screen provides genetic evidence
that flavonols interfere with shoot development in rol1-2 seedlings. The increased accumulation
of auxin in rol1-2 seedlings appears to be caused by a flavonol-induced modification of auxin
transport. Quantification of auxin export from mesophyll protoplasts revealed that naphthalene-1
-acetic acid but not indole-3-acetic acid transport is affected by the rol1-2 mutation.
Inhibition of flavonol biosynthesis in rol1-2 fls1-3 restores naphthalene-1-acetic acid transport
to wild-type levels, indicating a very specific mode of action of flavonols on the auxin
transport machinery. 

Alleles; Arabidopsis; Arabidopsis Proteins; Biological Transport; Biosynthetic Pathways; Cell Shape; Cotyledon; Diffusion; Flavonols; Genetic Complementation Test; Green Fluorescent Proteins; Indoleacetic Acids; Mesophyll Cells; Mutation; Phenotype; Protoplasts; Recombinant Fusion Proteins; Suppression, Genetic; Arabidopsis thaliana; biosynthesis; cotyledons; functional foods; indole acetic acid; mechanism of action; mesophyll; mutants; naphthaleneacetic acid; pathogens; screening; secondary metabolites; seedlings; trichomes; article