title: Dissecting the mechanism of Solanum lycopersicum and Solanum chilense flower colour formation.
abstract: Flowers are the defining feature of angiosperms, and function as indispensable organs for sexual reproduction. Flower colour typically plays an important role in attracting pollinators, and can show considerable variation, even between closely related species. For example, domesticated tomato (S. lycopersicum) has orange/yellow flowers, while the wild relative S. chilense (accession LA2405) has bright yellow flowers. In this study, the mechanism of flower colour formation in these two species was compared by evaluating the accumulation of carotenoids, assessing the expression genes related to carotenoid biosynthetic pathways and observing chromoplast ultrastructure. In S. chilense petals, genes associated with the lutein branch of the carotenoid biosynthetic pathway, phytoene desaturase (PDS), ζ-carotene desaturase (ZDS), lycopene β-cyclase (LCY-B), β-ring hydroxylase (CRTR-B) and ε-ring hydroxylase (CRTR-E), were highly expressed, and this was correlated with high levels of lutein accumulation. In contrast, PDS, ZDS and CYC-B from the neoxanthin biosynthetic branch were highly expressed in S. lycopersicum anthers, leading to increased β-carotene accumulation and hence an orange/yellow colour. Changes in the size, amount and electron density of plastoglobules in chromoplasts provided further evidence of carotenoid accumulation and flower colour formation. Taken together, these results reveal the biochemical basis of differences in carotenoid pigment accumulation and colour between petals and anthers in tomato.
authors.affiliation: Joint Tomato Research Institute, School of Agriculture and Biology, Shanghai Jiao Tong University, Shanghai, China; Plant Biotechnology Research Center, School of Agriculture and Biology, Shanghai Jiao Tong University, Shanghai, China; Key Laboratory of Urban Agriculture (South) Ministry of Agriculture, School of Agriculture and Biology, Shanghai Jiao Tong University, Shanghai, China.
authors.forename: M
authors.initials: M
authors.lastname: Gao
authors.forename: H
authors.initials: H
authors.lastname: Qu
authors.forename: L
authors.initials: L
authors.lastname: Gao
authors.forename: L
authors.initials: L
authors.lastname: Chen
authors.forename: R S J
authors.initials: RS
authors.lastname: Sebastian
authors.forename: L
authors.initials: L
authors.lastname: Zhao
mesh_terms: D053898:Biosynthetic Pathways; D002338:Carotenoids / Q000235:genetics / Q000378:metabolism*; D003116:Color; D035264:Flowers / Q000235:genetics* / Q000254:growth & development / Q000378:metabolism / Q000648:ultrastructure; D018506:Gene Expression Regulation, Plant; D019753:Intramolecular Lyases / Q000235:genetics / Q000378:metabolism; D018551:Solanum lycopersicum / Q000235:genetics / Q000254:growth & development / Q000378:metabolism / Q000648:ultrastructure; D006899:Mixed Function Oxygenases / Q000235:genetics / Q000378:metabolism; D010088:Oxidoreductases / Q000235:genetics / Q000378:metabolism; D010641:Phenotype; D010940:Plant Proteins / Q000235:genetics / Q000378:metabolism*; D018087:Plastids / Q000378:metabolism / Q000648:ultrastructure*; D032322:Solanum / Q000235:genetics* / Q000254:growth & development / Q000378:metabolism / Q000648:ultrastructure; D013045:Species Specificity; D019207:beta Carotene / Q000235:genetics / Q000378:metabolism
chemical_list: D010940:Plant Proteins; D019207:beta Carotene; D002338:Carotenoids; D006899:Mixed Function Oxygenases; D010088:Oxidoreductases; C022398:phytoene dehydrogenase; C099215:zeta-carotene desaturase; D019753:Intramolecular Lyases; C070925:lycopene cyclase-isomerase
keywords: Carotenoids; chromoplast; flower colour; plastoglobule; structural gene; tomato