Probing carotenoid biosynthesis in developing seed coats of Bixa orellana (Bixaceae) through expressed sequence tag analysis

• Published in: Plant science (Limerick) Vol. 163; no. 1; pp. 141 - 145
• Main Authors: Jako, Colette, Coutu, Catherine, Roewer, Ingeborg, Reed, Darwin W, Pelcher, Lawrence E, Covello, Patrick S
• Format: Journal Article
• Language: English
• Published: Shannon Elsevier Ireland Ltd 01-07-2002; Elsevier Science
• Subjects: Agronomy. Soil science and plant productions; Biological and medical sciences; Bixa orellana; Bixin; Carboxyl methyltransferase; Carotenoid; Dioxygenase; Economic plant physiology; Expressed sequence tag; Fundamental and applied biological sciences. Psychology; Metabolism; Nitrogen metabolism and other ones (excepting carbon metabolism); Nutrition. Photosynthesis. Respiration. Metabolism; Plant physiology and development; Storage and secretion, pigments, phytochrome; Dioxygenase; Bixa orellana; Carboxyl methyltransferase; Bixin; DOXP, 1-deoxy- d-xylulose 5-phosphate; Expressed sequence tag; Carotenoid; EST, expressed sequence tag; Tegument; Seeds; Biosynthesis; Metabolic pathway; Bixaceae; Dye plant; Complementary DNA; Dicotyledones; Angiospermae; Spermatophyta
• ISSN: 0168-9452; 1873-2259
• DOI: 10.1016/S0168-9452(02)00083-3

Bixin is a commercially important diapocarotenoid derived from the seed coats of the tropical shrub
Bixa orellana. Based on available chemical data and by analogy to abscisic acid biosynthesis, a biosynthetic pathway for bixin starting from lycopene is proposed. This putative pathway was investigated through expressed sequence tag (EST) analysis using a subtracted cDNA library. This analysis identified ESTs corresponding to most of the enzymes of the carotenoid biosynthesis pathway including the 1-deoxy-
d-xylulose 5-phosphate pathway of plastids. ESTs corresponding to a number of genes encoding dioxygenases, aldehyde dehydrogenases and carboxyl methyltransferases were also identified. These represent candidate enzymes for the last stage of the bixin biosynthetic pathway.