Exploring molecular mechanisms underlying plant-AMF symbiosis

At the MycoSym Lab, we are aiming to investigate the molecular mechanisms underlying the symbiotic relationship between plant roots and arbuscular mycorrhizal fungi (AMF). The arbuscular mycorrhizal fungi (AMF) are a group of obligate symbionts within the subphylum Glomeromycotina (phylum Mucoromycota) that form symbiotic relationships with the roots of most land plants, as well as the thalli of rootless species.  AM fungi extend the reach of plant roots, thereby improving access to essential nutrients such as phosphorus and nitrogen. In return, plants provide carbon-rich sugars and lipids to the fungi. This ancient exchange fuels plant growth, boosts resilience, and plays a central role in carbon sequestration. 

AM effector project: In this project, we are particularly focusing on how fungal effectors, small secreted proteins that facilitate communication and interaction with the host plant, reprogram plant cellular processes, modulate signaling pathways, influence nutrient allocation, and reshape plant physiology during AMF-plant root symbiosis. We are using molecular and cell biological, biochemical, genetics, and multi-omics approaches to dissect the dynamic communication at the plant-fungal interface. A key focus is understanding how effector proteins contribute to nutrient uptake and to long-term carbon sequestration in soils. By decoding the molecular dialogue between plants and AM fungi, our goal is to develop sustainable strategies that improve nutrient use efficiency and support climate-resilient agriculture.

Membrane biogenesis and degeneration: AM fungi colonize plant roots and form arbuscules inside the cortical cells of the root during symbiosis. Arbuscules are highly branched structures formed inside the root cells of plants and are crucial for nutrient exchange between the fungus and the host plant. These structures    maximize the surface area for bidirectional nutrient exchange, primarily phosphorus from the fungus to the plant and carbon from the plant to the fungus. Importantly, arbuscules are formed in the apoplastic compartments and surrounded by a peri-arbuscular membrane (PAM) derived from the plant, creating a specialized symbiotic interface. Arbuscules and PAM formation is a dynamic process and requires production of the membranes. We aim to investigate the molecular players and mechanisms involved in this contstant membrane biogenesis and degeneration processes involved in AMF-plant symbiosis. 

Mamoona Khan PhD (principle investigator)

Yun Tang (PhD student)

Nesrin Kaiser (Masters student)

Matthia Comparini (Student helper)

For a full list of publication please visit:

Orcid: https://orcid.org/0000-0003-3301-9536

Google Scholar: https://scholar.google.com/citations?user=d5uhCusAAAAJ&hl=en

*Equal contribution,  # corresponding author

• Khan M#. N matters: Insights into nitrogen assimilation from the ectomycorrhizal fungus Laccaria bicolor. Plant Physiol. (2025) May 30;198(2):kiaf231. https://doi.org/10.1093/plphys/kiaf231
• Khan M, Uhse S, Bindics J, Kogelmann B, Nagarajan N, Tabassum R, Ingole KD, Djamei A. Tip of the iceberg? Three novel TOPLESS-interacting effectors of the gall-inducing fungus Ustilago maydis. New Phytologist (2024) Nov;244(3):949-961. https://doi.org/10.1111/nph.19967
• Khan M, Djamei A. TOPLESS Corepressors as an Emerging Hub of Plant Pathogen Effectors. Mol Plant Microbe Interact. (2024) Mar;37(3):190-195. https://doi.org/10.1094/MPMI-10-23-0158-FI
• Khan M#., Djamei A. Co-immunoprecipitation based identification of effector-host protein interactions from pathogen-infected plant tissue. Methods Mol Biol. 2023;2690:87-100.  (2023). Springer. https://doi.org/10.1007/978-1-0716-3327-4_8
• Khan M#., Djamei A. Performing Infection Assays of Sporisorium reilianum f. sp. Zea in Maize. Methods Mol Biology;2494:291-298 (2022). https://doi.org/10.1007/978-1-0716-2297-1_20
• Bindics J*., Khan M*., Uhse S., Kogelmann B., Baggely L., Reumann D., Ingole K., Stirnberg A., Rybecky A., Darino M., Navarrete F., Doehlemann G., Djamei A. Many ways to TOPLESS – manipulation of plant auxin signalling by a cluster of fungal effectors (2022). New Phytologist. https://doi.org/10.1111/nph.18315 
• Khan, M, Rozhon, W, Unterholzner, SJ, Chen, T, Eremina, M, Wurzinger, B, Bachmair, A, Teige, M, Sieberer, T, Isono, E and Poppenberger, B. “Interplay between phosphorylation and SUMOylation events determines CESTA protein fate in brassinosteroid signaling”. Nature Communications (2014) Aug 19;5:4687. DOI: 10.1038/ncomms5687
• Khan, M, Rozhon, W, and Poppenberger, B. Mini-Review ‘The role of hormones in the aging of plants. Gerontology 2014 ;60(1):49-55.  DOI: 10.1159/000354334
• Khan, M, Rozhon, W, Bigeard, J, Pflieger, D, Husar, S, Pitzschke, A, Teige, M, Jonak, C, Hirt, H and Poppenberger B. “Brassinosteroid-regulated GSK3/shaggy-like kinases phosphorylate MAP kinase kinases, which control stomata development in Arabidopsis thaliana”. Journal of Biological Chemistry (2013) Mar 15;288(11):7519-27. DOI: 10.1074/jbc.M112.384453

This publication was selected by the "Journal of Biological Chemistry" (JBC) as one of the 22 best papers of 2013 from more than 4000 JBC publications https://www.jbc.org/best-of-2013

• Poppenberger B*, Rozhon W*, Khan M*, Husar S, Adam G, Luschnig C, Fujioka S and Sieberer T. CESTA, a positive regulator of brassinosteroid biosynthesis. EMBO Journal 2011 Mar 16;30(6):1149-61. DOI: 10.1038/emboj.2011.35