Beneficial fungi induce lateral root development via a generic mechanism
Research by Crop Science Centre scientists’ sheds light on the relationship between arbuscular mycorrhizal fungi and lateral root development in angiosperms.
Professor Uta Paszkowski, an author of this research, said “This is a significant clarification of the molecular mechanisms triggering cell division, thereby underpinning crop root system architectural plasticity in the ecosystem. This forms an important part in our wider ambition to improve the nutrition of crops sustainably.”
Published in the journal Current Biology, this research has four key findings: the initiation of new lateral root primordia, generic chitin as a potent stimulus of lateral root development, conserved MAMP receptors to perceive the chitin signals and the broadly conserved response across diverse angiosperms.
The ability of arbuscular mycorrhizal fungi to increase lateral root numbers in various plant species has been widely observed. This research reveals that the cause is increased initiation of cell division and lateral root primordia formation.
This is a significant clarification of the molecular mechanisms triggering cell division, thereby underpinning crop root system architectural plasticity in the ecosystem. This forms an important part in our wider ambition to improve the nutrition of crops sustainably.
Professor Uta Paszkowski
This enhanced lateral root development was thought to be activated by symbiosis relevant signals, such as LCOs or CO4. However, the authors of this research clarify that lateral root development is generic to diverse chitin-derived molecules. Furthermore, the authors present genetic evidence demonstrating a conserved lateral root developmental response to chitinaceous molecules across phylogenetically distant angiosperms, involving a dedicated set of MAMP receptors.
In a broader ecological and evolutionary context, the exact biological significance of this conserved response requires more investigation. The authors speculate that the detection process of chitinaceous molecules might facilitate the monitoring of the soil biota.
This pre-existing signalling pathway might be an ancestral feature of all plants engaging in nitrogen-fixing symbioses where diazotroph bacteria also employ chitinaceous LCOs to stimulate cell-division leading to nodule formation. This finding is therefore important for potential engineering of nitrogen fixation into cereal crops.
This research forms part of a wider programme to improve the sustainability of equity of global agriculture by reducing the need for inorganic fertilizer. This will be particularly beneficial for small-holder farmers in sub-Saharan Africa who do not have access to inorganic fertilisers to increase the yield of their crops.
