Poster: Lipids & Related Molecules
Abs #
859: Intron in 5¡¯UTR of microsomal oleic acid desaturase (FAD2) gene is essential for enhancement of gene expression
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Presenter: |
Suh, Mi Chung , michung@korea.ac.kr |
Authors | Suh, Mi Chung (A) Kim, Mi Jung (A) Shin, Jeong-Sheop (A) Chung, Chung-Han (B) | | Affiliations: |
(A): Graduate School of Biotechnology, Korea University
(B): Division of Biotechnology, Faculty of Life Sciences and Resources, Dong-A University
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Sesame (Sesamum indicum) is an important oil seed crop producing 50% oil of seed dry weight in Asian countries. The polyunsaturated fatty acid content is one of the major factors influencing the quality of vegetable oils. It was reported that microsomal oleic acid desaturase (FAD2) was responsible for the high linoleic acid content (approximately 40% of total fatty acids) in sesame storage oil. To investigate regulatory regions involved in spatial and temporal expression of FAD2 gene and the influence of an intron in 5¡¯-untranslated region (UTR), genomic clones encoding microsomal oleic acid desaturase (Si-FAD2) and their 5¡¯ flanking regions were isolated from sesame and Arabidopsis plants based on inverse-PCR or Arabidopsis genome sequence. Both FAD2 genes contain only one large intron within 5¡¯- UTR and their transcription initiation sites were identified by 5¡¯-cRACE. The 5' flanking region of each FAD2 gene was fused to the b-glucuronidase (GUS) reporter gene and introduced into Arabidopsis thaliana plants. Histochemical GUS staining showed that sesame FAD2 promoter was restricted to the seed tissues which is coincident with the period of storage lipid synthesis, whereas Arabidopsis FAD2 gene promoter was constitutively turned on in all tissues tested. GUS gene expression was 3- to 20 fold increased by the presence of intron sequence from both sesame and Arabidopsis plants. Possible cis-elements in 5¡¯ flanking regions of two FAD2 genes will be analyzed by particle bombardment or transgenic approach. FAD2 promoter and intron sequence might be useful for enhancement of foreign gene expression and especially improvement of seed oil in transgenic plants.
