THE CENTRAL ROLES OF IRON AND CALCIUM FOR PLANT/MICROBE INTERACTION AND SHAPING MICROBIAL COMMUNITIES IN THE SOIL

Roots are associated with a large number of different microbes, which can form beneficial, neutral or pathogenic interactions. “Infochemicals” from the microbial community, released into the soil or plants, induce signaling processes in the root cells which determine the fitness of a plant and its response to the environment. The plant integrates the information from the different microbes for an appropriate and balanced response. On the other hand, the microbial community is shaped by signals from the roots. We have established a symbiotic interaction system, in which the information exchange between the model plant Arabidopsis thaliana and a beneficial, plant-growth promoting endophytic fungus, called Piriformospora indica, can be studied and compared with other root-interacting microbes. Biochemical and molecular-genetic data indicate that two ions, calcium and iron, are major players in determining the fitness of the plant and the response to microbial signals. We will highlight the central role of these two ions in plant/microbe interactions