Reporter genes: applications to the study of arbuscular mycorrhizal (AM) fungi and their symbiotic interactions with plant roots

Genetic reporters are versatile and powerful tools for analysis of diverse biological processes ranging from gene transcription to protein and organelle localisation. The recent development of genetic reporters for use with fungi may also aid our understanding of biological processes underlying interaction with symbiotic and pathogenic fungi and the host. Arbuscular mycorrhizal (AM) fungi represent an elusive group of ubiquitous symbiotic fungi that have been relatively unstudied in planta and within the soil due to their obligate status and their culturing difficulties. However, the advent of the transformation technology to introduce genetic reporters into these fungi, has provided the opportunity to study these organisms in great detail. In this paper we review the many areas where genetic reporters may play a key role in increasing our understanding of AM fungi and their symbiotic interactions with plant roots.