Résumé
The majority of terrestrial plants live in symbiotic associations with fungi or bacteria that improve their nutrition. Critical steps in such a symbiosis are mutual recognition and subsequent establishment of an intimate association that involves the penetration of plant tissues and, in many cases, the invasion of individual host cells by the microbial symbiont. The most widespread symbiosis of plants is the arbuscular mycorrhizal (AM) symbiosis, which can improve plant nutrition and stress resistance. The AM symbiosis is controlled by intrinsic factors such as SYM symbiosis genes, and extrinsic factors such as nutrients. Important experimental systems in symbiosis research are legumes (Medicago truncatula and Lotus japonicus) and grasses (rice and maize), but Solanaceae are also catching up. In this chapter, we summarize recent advances in AM research on Petunia, which complement ongoing efforts in the AM research community.