Light-induced betacyanin and flavonol accumulation in bladder cells of Mesembryanthemum crystallinum.
Treatment of the halophyte Mesembryanthemum crystallinum L. (ice plant) (Aizoaceae) with high intensities of white light resulted in a rapid cell-specific accumulation of betacyanins and flavonoids with 6-methoxyisorhamnetin 3-O-¿[(2"'-E-feruloyl)-3"'-O-(beta-D- glucopyranosyl)](2"-O-beta-D-xylopyranosyl)]-beta-D-glucopyranoside (mesembryanthin) as the predominant component, within bladder cells of the leaf epidermis. Induced accumulation of these metabolites was first detected 18 h after the initiation of light treatment in bladder cells located at the tip of young leaves followed by the bladder cells located on the epidermis of fully expanded leaves. UV-A light apparently is sufficient to induce accumulation of betacyanins and flavonoids. Application of 2-aminoindan 2-phosphonic acid, a specific inhibitor of phenylalanine ammonia-lyase (PAL; EC 4.3.1.5), not only inhibited the accumulation of flavonoids but also reduced betacyanin formation. Based on these observations we suggest these bladder cells as a model system to study regulation of betacyanin and flavonoid biosyntheses.
Vogt
T
T
Institut für Pflanzenbiochemie, Halle, Saale, Germany. tvogt@ipb.uni-halle.de
Ibdah
M
M
Schmidt
J
J
Wray
V
V
Nimtz
M
M
Strack
D
D
D000872:Anthocyanins / Q000378:metabolism*; D002240:Carbohydrate Sequence; D005419:Flavonoids / Q000378:metabolism*; D044948:Flavonols; D006027:Glycosides / Q000378:metabolism; D008027:Light; D008969:Molecular Sequence Data; D010860:Pigments, Biological / Q000378:metabolism*; D059828:Plant Cells; D018515:Plant Leaves / Q000166:cytology / Q000378:metabolism / Q000528:radiation effects; D010944:Plants / Q000378:metabolism* / Q000528:radiation effects*
D000872:Anthocyanins; D005419:Flavonoids; D044948:Flavonols; D006027:Glycosides; D010860:Pigments, Biological