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Carotenoid Pathway in Capsicum Annuum Laura Rodriguez- Uribe Department of Plant and Environmental Sciences, New Mexico State University, Las Cruces, NM USA. Carotenoids.
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CarotenoidPathway in Capsicum AnnuumLaura Rodriguez-UribeDepartment of Plant and Environmental Sciences, New Mexico State University, Las Cruces, NM USA
Carotenoids • Most abundant natural pigments, more than 700 carotenoids have been identified in photosynthetic organisms such as plants, algae, and bacteria Carrot Corn Tomato Pepper β-carotene Lutein/ZeaxanthinLycopeneCapsanthin/Capsorubin Algae Bacteria β-carotene Deinoxanthin
Carotenoid biosynthetic pathway in Capsicum Peppers possess the most evolved carotenoid pathway
Carotenoid biosynthesisand accumulation Fruit wall Carotenoid composition changes during fruit ripening Chromoplasts
Biological Antioxidants, Vitamin A precursor Nutritional supplements Carotenoidsquench free radicals, prevent protein oxidation and DNA damage Sources of Free Radicals: Effects: Cigarette smoke Cancers Environmental pollutants Atherosclerosis Radiation Damaged DNA Ultraviolet light Heart disease Pesticides Rheumatoid arthritis
Industry New Mexico red pepper Pigments (natural dyes) Cosmetics
Thin layer chromatography with the carotenoid composition at different ripening stages G GO O G GO O G GO O Cs Cr V Green Green/Orange Valencia FogoNuMex Standards Sunset Orange
Objectives • Investigate the β-carotene content of orange fruited capsicum varieties to correlate the relationship between fruit color and β-carotene content
Carotenoid biosynthetic genes in orange colored peppers • Carotenoid pathway genes phytoenesynthase (Psy), lycopene-βcyclase (Lcyb), β-carotenoidhydrolase (CrtZ-2), and casanthin-capsorubinsynthase (Ccs), from six orange fruited peppers were cloned and sequenced. • Mutations in the Lcyb of the six orange peppers, and a new version of the Ccsgene from Fogo pepper genes.
Multiple alignment of the capsanthin- capsorubinsynthase protein Multiple alignment with the Ccs amino acid sequences from Yolo wonder, Valencia, and Fogo.
Expression of carotenoid biosynthetic genes during ripening in orange peppers G GO O G GO O G GO O Psy Lcyb CrtZ-2 Green Ccs EtBr Green/Orange Valencia Fogo NM Sunset Orange
Approaches to test the functionality of the CCS mutant • Biotechnological: Expression of the wild type and mutant Capsanthin-Capsorubinsynthases as recombinant proteins in an heterologous system such as Escerichia. Coli (E.coli) and assay its activity. • Biochemical: Purification and characterization of the Capsanthin-Capsorubin from Valencia and Fogo peppers chromoplasts
Expression of Capsanthincapsorubinsynthase in E. coli as a recombinant protein kD 1 2 3 4 5 6 7 75 50 37 25 Ccs 75 75 75 50 37 25 50 37 25 50 37 25
Purification of CCS from pepper fruit wall chromoplasts Chromoplast Percoll density gradient Fruit wall Isolation and Purification of CCS protein
Conclusions Carotenoid composition differs among peppers The six orange peppers in this study have a new version of the Lcyb gene A novel version of the Ccs gene was found in the Fogo cultivar Differences in gene expression in the carotenoid pathway might determine the carotenoid composition in mature peppers .
Overall Significance NMSU Research Metabolomics / Breeding New Mexico Breeders World Nutrition Nutrient + Pigment Rich Peppers ↑ β-Carotene ↑ Capsanthin/Capsorubin ↑ Quality in New Mexico Improvement of other agronomically important crops
Thank You! Dr. Mary A. O’Connell Dr. Paul Bosland Dr. Richard D. Richins Chile Pepper Institute Lab members Supported in part by NM Agricultural Experiment Station and NIH grant R25 GM61222
CarotenoidChemistry • Two kinds of carotenoids » Non Pro-Vitamin A lycopene » Pro-Vitamin A -carotene