Taxonomic group: plant / Streptophyta
(Phylum: Streptophyta)
Publication DOI: 10.1111/nph.12558Journal NLM ID: 9882884Publisher: Blackwell Publishing
Correspondence: schaeffner
helmholtz-muenchen.de
Institutions: Institute of Biochemical Plant Pathology, Helmholtz Zentrum München, Neuherberg, Germany, Research Unit Environmental Simulation, Helmholtz Zentrum München, Neuherberg, Germany, Institute of Experimental Botany, Academy of Sciences of the Czech Republic, Prague 6, Czech Republic, Department of Botany and Plant Biology, University of Geneva, Sciences III, Geneva 4, Switzerland
Polar auxin transport (PAT) plays key roles in the regulation of plant growth and development. Flavonoids have been implicated in the inhibition of PAT. However, the active flavonoid derivative(s) involved in this process in vivo has not yet been identified. Here, we provide evidence that a specific flavonol bis-glycoside is correlated with shorter plant stature and reduced PAT. Specific flavonoid-biosynthetic or flavonoid-glycosylating steps were genetically blocked in Arabidopsis thaliana. The differential flavonol patterns established were analyzed by high-performance liquid chromatography (HPLC) and related to altered plant stature. PAT was monitored in stem segments using a radioactive [3H]-indole-3-acetic acid tracer. The flavonoid 3-O-glucosyltransferase mutant ugt78d2 exhibited a dwarf stature in addition to its altered flavonol glycoside pattern. This was accompanied by reduced PAT in ugt78d2 shoots. The ugt78d2-dependent growth defects were flavonoid dependent, as they were rescued by genetic blocking of flavonoid biosynthesis. Phenotypic and metabolic analyses of a series of mutants defective at various steps of flavonoid formation narrowed down the potentially active moiety to kaempferol 3-O-rhamnoside-7-O-rhamnoside. Moreover, the level of this compound was negatively correlated with basipetal auxin transport. These results indicate that kaempferol 3-O-rhamnoside-7-O-rhamnoside acts as an endogenous PAT inhibitor in Arabidopsis shoots.
Arabidopsis thaliana, flavonol glycoside, flavonol biosynthesis, flavonol glycosyltransferases, plant growth, polar auxin transport
Structure type: oligomer
Location inside paper: Figure 1
Trivial name: astragalin
Compound class: glycoside, flavonoid glycoside, flavonol glycoside
Contained glycoepitopes: IEDB_142488,IEDB_146664,IEDB_983931,SB_192
Methods: biological assays, HPLC, LC-MS, genetic manipulations
Enzymes that release or process the structure: UGT78D2
Related record ID(s): 60894, 60895, 60896, 62230
NCBI Taxonomy refs (TaxIDs): 3702Reference(s) to other database(s): CCSD:
34076, CBank-STR:4070
Show glycosyltransferases
There is only one chemically distinct structure:
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