Leipzig/Jena. Plants are constantly challenged by hungry animals and infectious microbes. Tomato plants, for example, are often infested with little worms that feed on their roots. A fungus can help them to better defend themselves against these attacks, scientists report in the journal New Phytologist. In the future, farmers and gardeners might benefit from the new findings, as they may be able to use a kind of 'fungus-vaccinatio'n to prepare their tomato plants for impeding an infestation with worms.