Improvement of the diffusion model

The model created seems robust on the scale of phenomena studied. Plausible results are observed for all scales of values analyzed. The most obvious improvement is the determination of the parameters. Indeed the diffusion coefficients, the rate of production of signal molecules and the concentration necessary for detection have been chosen arbitrarily and must be adapted to the medium, the signal and the types of roots studied. Only one type of plant has been analyzed by modeling, even if the results are a priori similar for any type of plant,  the mode should be run with different root phenotype in order to validate this assumption. More differentiation in the model of the collecting roots could be used to characterize the signal transmission time for each type of root and thus improve the specificity of the results that remain  very general in this model. 
We consider emitting plant emit signal directly after germination of seeds. It is a huge assumption and it is important to remind that an active communication process is composed in addition at least of a identification of the signal to transfer and the creation of the signal, or at least a reaction to the environement in the case of a passive communication. To this are added the transfer of the signal and possibly a response. Those phenomena take time and extend the communication time. We did not need to work on those phenomenon because we find that transfert time is long enough to exclude the communication hypothesis.

Conclusions

We tried to develop models allowing to test different circumstances. We can use them by varying different parameters such as the growth rate of roots and myccorhizea, the distance between both plants, the diffusion coefficient... It is very important to stay critical regarding the results. The modelling process sometimes provides very different results from the experimentation.
In the American experiment, the response seems to happen very quickly. None of the communication ways we tested can explain such a quick response.

Bibliography

Annex

Annex I : Conducts a simulation suite where the growth rate of mycorrhizae varies for each simulation

Script to change the value of mycorrhizal growth rate and record the result (need of io_function.R)