Team:Shenzhen SZMS/Project

From 2014hs.igem.org

Revision as of 00:12, 20 June 2014

Find more of our project below!

Background

Our project is to create an “E. coli Plant-sitter” that achieves smart maintenance of healthy plant growth through the application of synthetic biology to temperature moderation. We hope that our toolkit will aid the process of plant cultivation, enlarge the public understanding of synthetic biology, and make the methods and technology of synthetic biology accessible to people’s daily life. Daily life – yes, on earth our Plant-sitter can be well applied to the growth of plants – but what about…

Wait for it –

MARS!

[http://en.wikipedia.org/wiki/Mars Mars], lying four hundred million kilometers from earth, has the most earth-like seasons due to Mars and Earth’s similar tilts of rotational axes. Mars’ surface temperature varies from −143℃ to 35℃, a range wider than and lower than that of Earth because 1) its further distance from the Sun; 2) its thin atmosphere cannot store much solar heat; 3) its soil’s thermal inertia is low. As a result, in order for men to make use of Martian resources and to develop its potential as an alternative human residence in the universe – according to the Mars Migration Program issued by SpaceX, founding a human community on Mars requires 1) releasing carbon dioxide to make the atmosphere denser and to create raw materials for photosynthesis; 2) cultivating plants to release oxygen. Our project is an ideal match for this application – with the methods and technology of synthetic biology, the E.coli Plant-sitter is able to keep the temperature at around 27℃, aiding the plants who are burdened with the glorious purpose of generating oxygen to defend against the Jotunheim weather on Mars.

Plants whose preferential temperature ranges from 25~30℃ are exposed to the threat of low productivity and unhealthy growth in overly cold environments. Therefore, we came up with a system that aids the healthy growth of these plants by protecting them from overly low temperatures through smart temperature control. Our system of temperature moderation includes two parts, temperature sensing and temperature regulating.

Plasmid and Working Details

Compile	Function	Introduction
J23106	Promoter	It promotes the transcription of the following parts. [http://parts.igem.org/Part:BBa_J23106 More]
R0051	CI regulated Promoter	It promotes the transcription without CI. When CI is binding to it,it is repressed. [http://parts.igem.org/Part:BBa_R0051 More]
K115016	27℃ RBS	It only promotes the translation when the temperature is over 27℃ [http://parts.igem.org/Part:BBa_K115016 More]
K115017	32℃ RBS	It only promotes the translation when the temperature is over 32℃ [http://parts.igem.org/Part:BBa_K115017 More]
B0030	strong RBS	It can promotes the translation strongly. [http://parts.igem.org/Part:BBa_B0030 More]
C0051	Coding sequence	It is the coding sequence of CI Protein. [http://parts.igem.org/Part:BBa_C0051 More]
1.7.7.2 (KEGG)	Coding sequence	We got this part from bacillus subtilis best7613 strain.It catalyzes the reaction which converts Nitrate to Nitrite. [http://www.genome.jp/dbget-bin/www_bget?ec:1.7.7.2 More]
K145015	Coding scquence	It is the coding sequence of GFP. [http://parts.igem.org/Part:BBa_K145015 More]
B0015	Terminator	It can stop the transcription. [http://parts.igem.org/Part:BBa_B0015 More]

The process of temperature sensing involves a promoter, a 27℃ RNA thermometer, and cI. The process of temperature regulating involves a cI regulated promoter, an enzyme which catalyzes an exothermic chemical reaction, a 32℃ RNA thermometer, and a GFP LVA device which serves to indicate the occurrence of a change in temperature. The promoter in temperature sensing part is consistently on and thus so is the process of cI’s transcription from DNA to RNA. When the temperature is below 27℃, the 27℃RNA thermometer takes a curved, locked structure which does not enable translation from RNA to protein cI, which in turn allows the activation of the cI regulated promoter, the production of the enzyme, the occurrence of an exothermic reaction which heats up the environment, and the expression of GFP LVA tag which gives out green light to indicate that the temperature is below 27℃ and that our device of temperature control is doing its work. When the temperature rises and reaches 27 ℃ as a result of the exothermic reaction, the 27℃ RNA thermometer enables the translation of cI protein, which in turn represses the cI regulated promoter, ending the release of heat through the exothermic reaction by stopping the production of the enzyme which catalyzes that reaction. As a result of an inactive promoter (the cI regulated), the GFP also stops its expression and is decomposes, indicating that the temperature has risen from below 27 ℃ to 27 ℃and that our system of temperature control has done its work. If the 27℃ RNA thermometer fails to stop the heating process at around 27℃ and the temperature keeps rising up to 32℃, the 32℃ RNA thermometer is activated, leading to the presence of protein cI, which places a double-check on the inhibition of the heating process.

Temperature Sensing

This process involves BBa_J23106 (promoter), BBa_K115016 (27℃ RNA thermometer), and cI (Repressor protein cI). BBa_J23106 is consistently on and thus so is the process of cI’s transcription from DNA to RNA. When the temperature is below 27℃, the 27℃ sensitive RNA thermometer does not enable translation from RNA to protein cI, which in turn allows the activation of BBa_R0051, the production of the enzyme, the occurrence of an exothermic reaction which heats up the environment, and the expression of GFP LVA tag which gives out green light to indicate that the temperature is below 27℃ and that our device of temperature control is doing its work.

When the temperature rises and reaches 27 ℃ as a result of the exothermic reaction, BBa_K115016 (27℃ RNA thermometer) enables the translation of cI protein, which in turn represses BBa_R0051, ending the release of heat through the exothermic reaction by stopping the production of the enzyme which catalyzes that reaction.

As a result of an inactive promoter (BBa_R0051), the GFP also stops its expression and is decomposes, indicating that the temperature has risen from below 27 ℃ to 27 ℃and that our system of temperature control has done its work.

If BBa_K115016 (27℃ RNA thermometer) fails to stop the heating process at around 27℃ and the temperature keeps rising up to 32℃, BBa_K115017 (32℃ RNA thermometer) is activated, leading to the presence of protein cI, which places a double-check on the inhibition of the heating process.

The process by which our temperature-control system operates may be better illustrated in the following flow chart:

Temperature Regulating

The process of temperature regulating involves BBa_J45503 (cI regulated promoter), an enzyme which catalyzes an exothermic chemical reaction, BBa_K115017 (32℃ RNA thermometer) and a GFP LVA device which serves to indicate the occurrence of a change in temperature.

The following is a flowchart explaining how our E. coli Plant-sitter works.