Cross-talk of abiotic and biotic stress responses

In the field, crop plants are exposed to different abiotic or biotic stress conditions which may have negative effects on performance and finally yield. An interesting, so far underrated aspect is that normally there are more than one stressors acting at the same time on plants life and that the different stress response pathways mutually affect each other. Recent findings prove that plants "learned” to cope with such complex situations of co-stress and that single stress-response pathways do not act independently, but are rather interconnected on a molecular regulatory level. To identify factors involved in this cross-talk, in a first step one can identify genes which are agonistically or antagonistically regulated under different stress-situations. In previous work, we performed extensive transcriptome analyses to identify genes in the model crop barley which are regulated under natural senescence, under drought stress, in response to nitrogen limitation, in response to biotic attack or in response to a combination of stressors. In addition, we compared drought-responsive gene expression in a drought tolerant barley land race with that of a modern elite line. Out of these global approaches we want to extract a set of genes, encoding regulatory factors (e.g. transcription factors, epigenetic factors) which show an agonistic or antagonistic regulation under different stress-situations (e.g. up-regulation in response to pathogen attack, and down-regulation during abiotic stress), indicating central functions in the complex interacting regulatory networks of abiotic and biotic stress responses. Aim of the planned work is to clarify regulation and involvement of these candidate genes in cross-talk under co-stress.