From 2011.igem.org

Revision as of 16:45, 19 September 2011

Main Results

Phyto Route

We observed uptake of GFP-expressing bacteria into plant roots (Fig. 1). The fact that (at least some) plants can actively break up bacteria and use them for nutrients was only reported last year (REF). This finding is of extreme importance to our project as the exposure of roots to indole 3-acetic acid will vary significantly if the uptake of the compound takes place inside the roots themselves rather than from the outside. This also presents a novel platform of indirectly engineering plants as delivery of a whole range of compounds will be possible using this method.

Figure 1: Escherichia coli cells expressing superfolder GFP (sfGFP) can be seen inside an Arabidopsis thaliana root using confocal microscopy after overnight incubation of the plants with bacteria. Roots were washed in PBS prior to imaging to avoid "wrong positives" of bacteria adhering to the outside of the root (Data and imaging by Imperial iGEM 2011).

Auxin Xpress

We exposed Arabidopsis seedlings to our auxin-producing bacteria to observe their effect on the roots. For this, we used a reporter line that expresses YFP in response to indole 3-acetic acid. As controls, we used a culture of seedlings that was not incubated with any bacteria and a control that was indicated with E. coli not expressing IAA. Fluorescence was brightest in the roots incubated with auxin-expressing bacteria (Video 2).

Video 2.