Seed specific gene promoters

The FAEl gene was subcloned behind the seed-specific napin promoter and transgenic plants were generated. Analysis of seed showed that FAEl was able to synthesize VLCFAs (Table 2). 

In order to study the processes of plant fatty acid desaturation and glycerolipid biosynthesis and to develop a crop seed oil with reduced level of saturated fatty acids, a rat liver stearyl-CoA A-9 desaturase (D9DS) gene was introduced into Nicotiana tahacum under the control of the 35S promoter via Agrobacterium transformation (3) and soybean somatic embryos with the seed-specific phaseolin promoter by particle bombardment. In this article, we decribe the effects of the mammalian A-9 desaturase on fatty acid composition of membrane and storage lipids. 

The case of canola is extraordinary because of the very high level accumulations (50-fold) of leaf-type carotenoids in seeds when the gene was introduced under the seed-specific promoter, napin. The exalbuminous seeds of canola differ from those of genetically engineered rice cereal grains in that they have chloroplasts, which may explain the capacity for hyperaccumulation of carotenoids. 

OUWERKERK, P.B., MEMELINK, J., A G-box element from the Catharanthus rosues strictosidine synthase (Str) gene promoter confers seed-specific expression in transgenic tobacco plants. Mol. Gen. Genet., 1999,261, 635-643. 

Other c(5-elements involved in ABA induced transcription are a seed-specific element which mediates induction by ABA of the Cl gene in maize endosperm [33], an element from the promoter of the C. plantagineum gene CDeT27-45 [60] and the TT motif (TTTCGTGT) from the DCS gene from carrot [43,86]. The TT motif can be viewed as an imperfect ABRE and two bZIP proteins that bind to the element have been cloned. 

The poly(3HB) biosynthetic pathway has also been successfully expressed in the leucoplasts of developing seeds of B. napus. In these experiments, the phaA, phaB, and phaC genes modified for plastid targeting were expressed imder the control of the Lesquerella fatty acid hydroxylase seed specific promoter. Plants... 

A -desaturase genes were isolated from cyanobacteria and Borago officinalis. Introduction of these genes into tobacco under the control of the cauliflower mosaic virus 35S promoter resulted in y-linolenic acid (GLA) production in leaf lipids. The use of seed specific promoters also resulted in significant levels of GLA in seed lipids. 

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