An Arabidopsis mutant defective in the general phenylpropanoid pathway

• Published in: The Plant cell 1992-11, Vol.4 (11), p.1413-1424
• Main Authors: Chapple, C.C.S. (Michigan State University, East Lansing, MI), Vogt, T, Ellis, B.E, Somerville, C.R
• Format: Article
• Language: English
• Subjects: ACIDE ORGANIQUE; ACIDE PHENOLIQUE; ACIDOS FENOLICOS; ACIDOS ORGANICOS; Arabidopsis - chemistry; Arabidopsis - genetics; Arabidopsis - metabolism; Biological and medical sciences; Biosynthesis; Choline - analogs & derivatives; Choline - metabolism; Cinnamates - metabolism; Classical genetics, quantitative genetics, hybrids; COMPOSE AROMATIQUE; COMPUESTOS AROMATICOS; Coumaric acids; Coumaric Acids - isolation & purification; Coumaric Acids - metabolism; CRUCIFERAE; Enzymes; ESTER; ESTERES; Esters; Esters - isolation & purification; Esters - metabolism; FEUILLE; FITOALEXINA; Fluorescence; Fundamental and applied biological sciences. Psychology; Genes, Plant - genetics; Genetic loci; Genetic mutation; Genetics of eukaryotes. Biological and molecular evolution; Histocytochemistry; HOJAS; Leaves; Lignin; Lignin - analysis; LIGNINAS; LIGNINE; LOCI; LOCUS; Malates - isolation & purification; Malates - metabolism; METABOLISME; METABOLISMO; MUTACION INDUCIDA; Mutagenesis; MUTANT; MUTANTES; MUTATION PROVOQUEE; Phenylpropionates - isolation & purification; Phenylpropionates - metabolism; PHYTOALEXINE; Plants; PROPIEDADES OPTICAS; PROPRIETE OPTIQUE; Pteridophyta, spermatophyta; RADIACION ULTRAVIOLETA; RAYONNEMENT ULTRAVIOLET; Seedlings; Seeds - chemistry; SINAPINA; SINAPINE; Vegetals
• ISSN: 1040-4651; 1532-298X
• DOI: 10.1105/tpc.4.11.1413

Mutants of Arabidopsis deficient in a major leaf phenylpropanoid ester, 2-O-sinapoyl-L-malate, were identified by thin-layer chromatographic screening of methanolic leaf extracts from several thousand mutagenized plants. Mutations at a locus designated SIN1 also eliminate accumulation of the sinapic acid esters characteristic of seed tissues. Because of increased transparency to UV light, the sin1 mutants exhibit a characteristic red fluorescence under UV light, whereas wild-type plants have a blue-green appearance due to the fluorescence of sinapoyl malate in the upper epidermis. As determined by in vivo radiotracer feeding experiments, precursor supplementation studies, and enzymatic assays, the defect in the sin1 mutants appears to block the conversion of ferulate to 5-hydroxyferulate in the general phenylpropanoid pathway. As a result, the lignin of the mutant lacks the sinapic acid-derived components typical of wild-type lignin