Plants produce a variety of chemical substances, which is why they either smell or stink to us humans; they taste sweet, sour or even pungent. It's the same for bacteria. Some choose their host plant according to the composition of their scents and flavors and colonize the leaves of different plants according to their preference. Most of these microorganisms (the "microbiome") are essential for the plants' survival, but some microorganisms make them sick. Here you can learn which different microorganisms live on leaves and how they use the pungent substances in mustard, broccoli or radishes in particular. Come along and find out how bacteria and plants influence each other!