Paper on feedback regulated bioelectronics for controlling adaptation of plants to drought

This paper will present the results on the feedback regulated bioelectronics system for controlling adaptation of plants to drought We will develop an organic electronic ion pump OEIP for abscisic acid ABA delivery Preliminary work at LiU has shown that ABA can be delivered by fiber based OEIPs Such OEIPS will be used for targeting the xylem of the model tree hybrid aspen Populus tremula x tremuloides mimicking the natural distribution route of the ABA hormoneWe will develop printed capacitive humidity sensors The sensors will be used to monitor soil water content simultaneously with controlled ABA release to the xylem transpiration stream The sensors will be realised by printing interdigitated coplanar electrodes on plastic flexible substrates The active area will be covered with a polymeric watersensitive layer whose dielectric permittivity is a function of the water content of the surrounding atmosphere Another approach consists of using the same capacitive structure but fabricated on a hygroscopic substrate such as paper UPDFinally we will evaluate the electronically controlled ABA responses in greenhouse grown aspen trees These experiments will allow specific ABA responses to be studied in isolation without a generic drought effect To assess plant responses to the treatments we will monitor stomatal conductance and photosynthetic efficiency using a Licor instrument and also assay gene expression changes in developing wood and leaves to identify genes responding to the treatments Such genes will become targets of more detailed molecular biology studies to understand the transcriptional networks underlying drought stress and tolerance We will also test the hypothesis whether it is possible to prime trees for drought stress by applying first an ABA pulse to transpiration stream and then reducing the water potential of the soil SLU LiU