Taxonomic group: plant / Streptophyta
(Phylum: Streptophyta)
Publication DOI: 10.1111/j.1365-313X.2006.02984.xJournal NLM ID: 9207397Publisher: Oxford: Blackwell Scientific Publishers and BIOS Scientific Publishers for the Society for Experimental Biology
Correspondence: chapple
purdue.edu
Institutions: Department of Biochemistry, Purdue University, 175 South University Street, West Lafayette, IN 47907-2063, USA
Sinapoylmalate is a major phenylpropanoid that is accumulated in Arabidopsis. Its presence causes the adaxial surface of leaves to fluoresce blue under UV light, and mutations that lead to lower levels of sinapoylmalate decrease UV-induced leaf fluorescence. The Arabidopsis bright trichomes 1 (brt1) mutant was first identified in a screen for mutants that exhibit a reduced epidermal fluorescence phenotype; however, subsequent examination of the mutant revealed that its trichomes are hyper-fluorescent. The results from genetic mapping and complementation analyses showed that BRT1 (At3g21560) encodes UGT84A2, a glucosyltransferase previously shown to be capable of using sinapic acid as a substrate. Residual levels of sinapoylmalate and sinapic acid:UDP-glucose glucosyltransferase activity in brt1 leaves suggest that BRT1 is one member of a family of partially redundant glycosyltransferases that function in Arabidopsis sinapate ester biosynthesis. RT-PCR analysis showed that BRT1 is expressed through all stages of plant life cycle, a result consistent with the impact of the brt1 mutation on both leaf sinapoylmalate levels and seed sinapoylcholine content. Finally, the compound accumulated in brt1 trichomes was identified as a sinapic acid-derived polyketide, indicating that when sinapic acid glycosylation is reduced, a portion of it is instead activated to its CoA thioester, which then serves as a substrate for chalcone synthase.
glucosyltransferase, Arabidopsis, polyketide, sinapic acid, sinapate ester, trichome, At3g21560
Structure type: monomer
Location inside paper: Figure 10
Contained glycoepitopes: IEDB_142488,IEDB_146664,IEDB_983931,SB_192
Methods: GC-MS, biological assays, HPLC, LC-MS, fluorescence microscopy, SEM, genetic manipulations
Enzymes that release or process the structure: UGT84A2
NCBI Taxonomy refs (TaxIDs): 3702
Show glycosyltransferases
There is only one chemically distinct structure:
Found 
report error