Rhizophagus irregularis is the most extensively studied arbuscular mycorrhizal (AM) fungus and one of the most agriculturally relevant soil microorganisms known. Its exceptionally wide host range, covering the majority of land plant species, combined with a well-characterised genome and unique obligate biotrophic lifestyle, make it an unparalleled model for understanding AM symbiosis at the molecular, physiological, and ecological level. Through mutualistic associations with plant roots, R. irregularis improves nutrient and water acquisition, enhances soil aggregation, and increases plant tolerance to abiotic and biotic stresses. Yet despite decades of research, fundamental aspects of its biology remain incompletely understood: how it coordinates host colonisation, regulates nutrient exchange at the arbuscular interface, adapts across different soil environments, and interacts with the broader rhizosphere microbial network.

This Research Topic focuses specifically on Rhizophagus irregularis as both a model organism and an applied biological tool, bridging mechanistic research with agricultural innovation. While general crop-microbe partnerships and root symbiosis have received growing attention in the literature, the depth of knowledge unique to R. irregularis spanning molecular signalling, strain-level variation, epigenetic regulation, and community ecology warrants a dedicated platform. In particular, this collection addresses an emerging frontier: the deliberate engineering of rhizosphere conditions using R. irregularis to improve crop resilience, soil carbon dynamics, and ecosystem functioning in stressed and degraded agricultural environments.

This Research Topic invites submissions across the biological, ecological, molecular, and agricultural dimensions of Rhizophagus irregularis research. Topics of interest include, but are not limited to:

• Molecular mechanisms of AM colonisation, arbuscule development, and nutrient exchange;

• Strain-level and intraspecific variation in R. irregularis and its functional consequences;

• Epigenetic and transcriptional regulation of R. irregularis-plant interactions;

• Rhizosphere microbiome modulation and synergistic interactions with PGPR and other beneficial microbes;

• AM fungal-mediated drought, salinity, and heat stress tolerance in crops;

• Soil carbon sequestration and enzyme activity linked to R. irregularis colonisation;

• Bioinoculant formulation, persistence, and field-scale effectiveness;

• Rhizosphere engineering strategies for sustainable and climate-resilient agriculture;

• Omics, systems biology, and ecological modelling approaches applied to R. irregularis.

We welcome Original Research Articles, Reviews, Mini-Reviews, Perspectives, and Methods papers. Studies integrating laboratory, greenhouse, and field-scale evidence are particularly encouraged.

Are you interested in contributing a manuscript to this Research Topic?

Rhizophagus irregularis in Sustainable Agriculture: Mechanisms, Stress Resilience, and Rhizosphere Engineering