title: Expression of phytoene synthase1 and carotene desaturase crtI genes result in an increase in the total carotenoids content in transgenic elite wheat (Triticum aestivum L.).
abstract: Dietary micronutrient deficiencies, such as the lack of vitamin A, are a major source of morbidity and mortality worldwide. Carotenoids in food can function as provitamin A in humans, while grains of Chinese elite wheat cultivars generally have low carotenoid contents. To increase the carotenoid contents in common wheat endosperm, transgenic wheat has been generated by expressing the maize y1 gene encoding phytoene synthase driven by a endosperm-specific 1Dx5 promoter in the elite wheat (Triticum aestivum L.) variety EM12, together with the bacterial phytoene desaturase crtI gene from Erwinia uredovora under the constitutive CaMV 35S promoter control. A clear increase of the carotenoid content was detected in the endosperms of transgenic wheat that visually showed a light yellow color. The total carotenoids content was increased up to 10.8-fold as compared with the nontransgenic EM12 cultivar. To test whether the variability of total carotenoid content in different transgenic lines was due to differences in the transgene copy number or expression pattern, Southern hybridization and semiquantitative reverse transcriptase polymerase chain reaction analyses were curried out. The results showed that transgene copy numbers and transcript levels did not associate well with carotenoid contents. The expression patterns of endogenous carotenoid genes, such as the phytoene synthases and carotene desaturases, were also investigated in wild-type and transgenic wheat lines. No significant changes in expression levels of these genes were detected in the transgenic endosperms, indicating that the increase in carotenoid transgenic wheat endosperms resulted from the expression of transgenes.
authors.affiliation: China-UK HUST-RRes Genetic Engineering and Genomics Joint Laboratory, The Genetic Engineering International Cooperation Base of Ministry of Science and Technology, The Key Laboratory of Molecular Biophysics of Ministry of Education, College of Life Science and Technology, Huazhong University of Science & Technology (HUST), Wuhan 430074, China.
authors.forename: Ling
authors.initials: L
authors.lastname: Cong
authors.forename: Cheng
authors.initials: C
authors.lastname: Wang
authors.forename: Ling
authors.initials: L
authors.lastname: Chen
authors.forename: Huijuan
authors.initials: H
authors.lastname: Liu
authors.forename: Guangxiao
authors.initials: G
authors.lastname: Yang
authors.forename: Guangyuan
authors.initials: G
authors.lastname: He
mesh_terms: D019883:Alkyl and Aryl Transferases / Q000235:genetics*; D002338:Carotenoids / Q000032:analysis*; D004885:Erwinia / Q000201:enzymology / Q000235:genetics; D015870:Gene Expression; D051232:Geranylgeranyl-Diphosphate Geranylgeranyltransferase; D010088:Oxidoreductases / Q000235:genetics*; D030821:Plants, Genetically Modified / Q000201:enzymology*; D012333:RNA, Messenger / Q000032:analysis; D020133:Reverse Transcriptase Polymerase Chain Reaction; D012639:Seeds / Q000737:chemistry; D014908:Triticum / Q000737:chemistry / Q000201:enzymology* / Q000235:genetics; D003313:Zea mays / Q000201:enzymology / Q000235:genetics
chemical_list: D012333:RNA, Messenger; D002338:Carotenoids; D010088:Oxidoreductases; D019883:Alkyl and Aryl Transferases; D051232:Geranylgeranyl-Diphosphate Geranylgeranyltransferase