title: Expression of carotenoid biosynthetic pathway genes and changes in carotenoids during ripening in tomato (Lycopersicon esculentum).
abstract: To study the expression pattern of carotenoid biosynthetic pathway genes, changes in their expression at different stages of maturity in tomato fruit (cv. Arka Ahuti) were investigated. The genes regulating carotenoid production were quantified by a dot blot method using a DIG (dioxigenin) labelling and detection kit. The results revealed that there was an increase in the levels of upstream genes of the carotenoid biosynthetic pathway such as 1-deoxy-d-xylulose-5-phosphate reductoisomerase (DXR), 4-hydroxy-3-methyl-but-2-enyl diphosphate reductase (Lyt B), phytoene synthase (PSY), phytoene desaturase (PDS) and ζ-carotene desaturase (ZDS) by 2-4 fold at the breaker stage as compared to leaf. The lycopene and β-carotene content was analyzed by HPLC at different stages of maturity. The lycopene (15.33 ± 0.24 mg per 100 g) and β-carotene (10.37 ± 0.46 mg per 100 g) content were found to be highest at 5 days post-breaker and 10 days post-breaker stage, respectively. The lycopene accumulation pattern also coincided with the color values at different stages of maturity. These studies may provide insight into devising gene-based strategies for enhancing carotenoid accumulation in tomato fruits.
authors.affiliation: Human Resource Development Department, Central Food Technological Research Institute (CSIR), Mysore, 570 020, India.
authors.forename: Kanakapura Krishnamurthy
authors.initials: KK
authors.lastname: Namitha
authors.forename: Surya Narayana
authors.initials: SN
authors.lastname: Archana
authors.forename: Pradeep Singh
authors.initials: PS
authors.lastname: Negi
mesh_terms: D019747:Aldose-Ketose Isomerases / Q000235:genetics / Q000378:metabolism; D019883:Alkyl and Aryl Transferases / Q000235:genetics / Q000378:metabolism; D053898:Biosynthetic Pathways; D002338:Carotenoids / Q000096:biosynthesis* / Q000235:genetics; D002851:Chromatography, High Pressure Liquid; D003001:Cloning, Molecular; D015536:Down-Regulation; D005638:Fruit / Q000235:genetics / Q000378:metabolism*; D018506:Gene Expression Regulation, Plant; D051232:Geranylgeranyl-Diphosphate Geranylgeranyltransferase; D000077276:Lycopene; D018551:Solanum lycopersicum / Q000235:genetics* / Q000378:metabolism; D009097:Multienzyme Complexes / Q000235:genetics / Q000378:metabolism; D010088:Oxidoreductases / Q000235:genetics / Q000378:metabolism; D018749:RNA, Plant / Q000235:genetics; D019207:beta Carotene / Q000096:biosynthesis* / Q000235:genetics
chemical_list: D009097:Multienzyme Complexes; D018749:RNA, Plant; D019207:beta Carotene; D002338:Carotenoids; D010088:Oxidoreductases; C114231:1-deoxy-D-xylulose 5-phosphate reductoisomerase; C022398:phytoene dehydrogenase; C099215:zeta-carotene desaturase; D019883:Alkyl and Aryl Transferases; D051232:Geranylgeranyl-Diphosphate Geranylgeranyltransferase; D019747:Aldose-Ketose Isomerases; D000077276:Lycopene