title: Earlier flowering induced by over-expression of CO gene does not accompany increase of artemisinin biosynthesis in Artemisia annua.
abstract: The early flowering gene CONSTANS (CO) from Arabidopsis thaliana was transferred into Artemisia annua using the Agrobacterium tumefaciens-mediated transformation system. The plant expression vector pBI CO was constructed by inserting the CO gene into the binary vector pBI121 under the control of CaMV 35S promoter. Analyses of PCR, PCR Southern blot, and Southern blot revealed that the transgenic plants contained the foreign CO gene. The results of RT-PCT and RT-PCR Southern blot suggested that the foreign CO gene had expressed at the transcriptional level. Although the flowering time of the CO transgenic plant was about 2 weeks earlier than that of the non-transgenic plant under short-day conditions, no significant difference in artemisinin content was found between the flowering transgenic plant and the non-flowering non-transgenic plant. These results show that the usually observed increase of artemisinin content before plant flowering under natural conditions is not a direct consequence of flowering itself, perhaps there is even no direct linkage between flowering and artemisinin biosynthesis.
authors.affiliation: Key Laboratory of Phytosynthesis and Environmental Molecular Physiology, Institute of Botany, The Chinese Academy of Sciences, Nanxincun 20#, Xiangshan, Haidian District, Beijing 100093, China.
authors.forename: H
authors.initials: H
authors.lastname: Wang
authors.forename: Y
authors.initials: Y
authors.lastname: Liu
authors.forename: K
authors.initials: K
authors.lastname: Chong
authors.forename: B Y
authors.initials: BY
authors.lastname: Liu
authors.forename: H C
authors.initials: HC
authors.lastname: Ye
authors.forename: Z Q
authors.initials: ZQ
authors.lastname: Li
authors.forename: F
authors.initials: F
authors.lastname: Yan
authors.forename: G F
authors.initials: GF
authors.lastname: Li
mesh_terms: D016960:Agrobacterium tumefaciens / Q000235:genetics; D017360:Arabidopsis / Q000235:genetics; D029681:Arabidopsis Proteins / Q000235:genetics* / Q000378:metabolism; D031172:Artemisia annua / Q000235:genetics* / Q000254:growth & development / Q000378:metabolism; D037621:Artemisinins / Q000378:metabolism*; D004268:DNA-Binding Proteins / Q000235:genetics* / Q000378:metabolism; D035264:Flowers / Q000235:genetics* / Q000254:growth & development / Q000378:metabolism; D018506:Gene Expression Regulation, Plant; D005822:Genetic Vectors / Q000235:genetics; D030821:Plants, Genetically Modified; D011401:Promoter Regions, Genetic / Q000235:genetics; D020133:Reverse Transcriptase Polymerase Chain Reaction; D012717:Sesquiterpenes / Q000378:metabolism*; D013997:Time Factors; D014157:Transcription Factors / Q000235:genetics* / Q000378:metabolism
chemical_list: D029681:Arabidopsis Proteins; D037621:Artemisinins; C092776:CONSTANS protein, Arabidopsis; D004268:DNA-Binding Proteins; D012717:Sesquiterpenes; D014157:Transcription Factors; C031327:artemisinin