Welcome to IMC 2018 International Mycological Congress
Fungi, plants, bacteria: a network of dialogues and interactions
- P. Bonfante
Can we live without fungi? Microscopic entities or giants, friends or killers, degraders or producers, they all play crucial roles for life on our planet. Their presence has accompanied the history of humanity, but for a long time, due their largely hidden and unseen actions, their importance was not fully acknowledged and their phylogenetic relationships with animals and plants were erroneously described. Nowadays we are aware that fungi are powerful organisms, which can offer us new pharmaceuticals, help cleaning up waters and soils from contaminants, and provide crucial support to the green inhabitants of the planet. The aim of this presentation is to illustrate different strategies developed by fungi in order to beneficially interact with land plants. Fossil data reveal that fungi resembling modern Glomeromycotina were already associated with first land plants around 450 MYA. However, only today, thanks to the use of -omics technology, we can decipher their enigmatic genomes, reconstruct their metabolic pathways, describe their impact on plants, and identify the molecules involved in the dialogue occurring with their hosts. Thanks to this wealth of data, we can finally make hypotheses on the evolution and molecular mechanisms that make fungi so successful in time and space. Mycorrhizal fungi create networks not only with plants, but also with other soil inhabitants like animals, other fungi and bacteria. The dialogue with bacteria is particularly fascinating. Bacteria can live on the surface of mycelia and spores or, in a more intimate way, as endocellular symbionts inside fungal cells. In the past, the interactions between bacteria and fungi were mostly described as antagonistic in nature, however, most recent data describe cooperative activities between fungi and bacteria. Increasing attention is currently given to the concepts of microbiota and holobiont. In this context, on one hand mycorrhizal fungi are part of the plant microbiota, and represent a key component of the plant holobiont; on the other hand, they also possess their own microbiota. Thus, analogous to animals and plants, a mycorrhizal fungus may be seen at the center of a complex network of inter-kingdom interactions. An example of this tripartite symbiosis is Gigaspora margarita, an arbuscular mycorrhizal fungus that associates both with many plants and diverse endobacterial populations. Deciphering these multiple interactions will be a future goal, which may provide interesting insights into the capacity of mycorrhizal fungi to modulate their responses depending on the organism with whom they interact.