Team:Imperial College London/Project Auxin Future


Module 2: Auxin Xpress

Auxin, or Indole 3-acetic acid (IAA), is a plant growth hormone which is produced by several soil bacteria. We have taken the genes encoding the IAA-producing pathway from Pseudomonas savastanoi and expressed them in Escherichia coli. Following chemotaxis towards the roots and uptake by the Phyto Route module, IAA expression will promote root growth with the aim of improving soil stability.

Future Work

To carry on the work on the Auxin-Xpress module, there are a number of steps we would take in the immediate future and others that form part of our long term plan.

Short-term plans

1. Construct we would build to achieve optimal root growth.

We will aim to fine-tune IAA expression of our construct by using promoters of different strength. We know the IAA concentration for optimal root growth from modelling and data fitting.

2. Assessing the effect of our bacterial IAA on root morphology.

We will be exposing plants to our IAA-producing bacteria for a prolonged period of time and observe changes in dry-mass, root length and root branching compared to a control that has been exposed to E. coli not producing IAA.

Long-term plans

1. Computationally model the long-term uptake and distribution pattern of IAA inside roots.

A mathematical model will be developed to quantitatively describe the relationship between root growth and the IAA concentration level inside the root. This model will be intergrated into the IAA metabolism pathway and cell elongation process to give a more accurate prediction of the response of plants to a specific amount of IAA.

2. Testing and implementation in the field.

We have to ensure that the IAA secreted by our bacteria is beneficial for the environment and in no way detrimental to existing plants and ecosystems. For this, field trials will need to be conducted in much later stages of the project.

M2: Testing & Results M3: Gene Guard