Name: Malika Mezeli
Project title: In-soil trophic interactions between plants, rhizosphere bacteria and nematodes: improving availability of soil phosphorus.
Where based: The James Hutton Institute Dundee/Lancaster University
I retrained at Lancaster University with a MSc in Sustainable Agriculture and Food Security and quickly developed an interest in soil organic phosphorus (P). My interest came not only from the bio-chemical mechanisms informing P transformations in soil but also the geo-political issues and environmental problems associated with rock P fertiliser. Proff Phillip Haygarth supervised my dissertation, through whom I met Dr. Daniel Menezes who stirred my experimental work. My research characterised a phytase enzyme known to hydrolyse forms of organic phosphorus and the effect organic anions (citrate) have on their catalytic activity in soil. My work was closely affiliated with research in an existing consortium OPUS (Organic Phosphorus Utilisation in Soils)and I was very pleased to get the opportunity to work under some of the team at The James Hutton Institute as an experimental worker after my MSc. I look forward to developing these relationships throughout my PhD as they make up part of my supervisory team.
Phosphorus (P) is an essential mineral for plant and animal life, a finite resource associated with geo-political issues and environmental pollution. Recent work highlights that the predicted increase in P demands could be reduced by 50% globally by utilising residual soil organic phosphorus.
Phytase enzymes originating from bacteria, fungus and plant root exudates are known to hydrolyse organic phosphorus (Po) to orthophosphate, however experimental systems have failed to translate this into significant plant benefits. Nematode predation of phytase producing bacteria, root herbivory and plant influences on rhizospheric microbiome are known to drive nutrient dynamics. This studentship will increase our understanding of such plant, rhizosphere bacteria and nematode dynamics and how they impact plant P acquisition. Using both classical and advanced techniques I will examine the transformations of P through the soil-plant system, the trophic interactions that drive these changes and environmental conditions which affect them; improving P management but also better management of our soils as complex and necessary ecosystems.