Flavors

Flavors are perhaps to most interactive parts of the iGarden project. We currently have 2 flavors inserted into plants that are currently growing, with options and ideas for an additional three.

Miraculin

Miraculin is a 'flavor inverting' protein, found naturally in the fruit of the plant fruit of Synsepalum dulcificum. Not sweet by itself, miraculin binds to taste receptors on the tongue, possibly altering the structure of the receptors and causing traditionally 'sour' flavors to be received as 'sweet'.

We have obtained, synthesized and BioBricked the DNA sequence of miraculin. This has allowed us to work with it in the usual BioBrick fashion, facilitating insertion into the agrobacterium expression vector.

Preliminary tests in E. Coli have been positive, with our YFP-tagged proteins showing definite expression

Brazzein

Brazzein is a sweet-tasting protein that is found in the Western African fruit, the Oubli. The protein consists of a 191 amino acid sequence. It is sweeter than sugar and is used as an alternative low calorie sweetener.

We have obtained, synthesized and BioBricked the DNA sequence of brazzein. We were then able to flank this sequence with a plant specific promoter and terminator and insert this construct into the agrobacterium expression vector.

Preliminary tests in E. Coli have been positive, with our YFP-tagged proteins showing definite expression and a Western Blot also showing successful expression of Brazzein.

Valencene

We originally tried to extract RNA from Valencia oranges and then make a cDNA library. We then used PCR to amplify the Valencene sequence. Valencene is a gene that codes for a molecule that gives Valencia oranges their citrus flavor and aroma.

Unfortunately, after three attempts, we were not able to obtain a viable cDNA library. We then tried to extract genomic DNA. However, none of our PCR tries worked from the genomic DNA. We therefore began to explore alternate methods for obtaining the valencene gene (i.e. from another lab).

Wintergreen

wintergreen expression system   click to enlarge

The MIT 2006 iGEM team created a BioBricked system to express methyl salicyate, a mint smelling compound. By swapping-in plant specific promoters and inserting the system into the pORE open vector, we would be able to create mint-smelling plants.

Banana

banana expression system   click to enlarge

The Banana Scent pathway is also from the MIT 2006 iGEM team and is another example of how the iGarden system is well suited for the modular nature of the Parts Registry. Through addition of plant-specific promoters, and use of the now-BioBrick compatible pORE vectors, banana smelling plants could be achieved.