UPSC Seminar

Stephanie Watts-Fawkes
Wageningen University, The Netherlands

Title: Arbuscular mycorrhizal fungi affect plant zinc nutrition – from genes to plate

Host: Adam Frew

Abstract: 
Zinc (Zn) is an essential micronutrient for plant and human health, yet soil Zn deficiency is widespread in crop-growing regions. Arbuscular mycorrhizal (AM) fungi colonise plant roots and can supply Zn through the mycorrhizal uptake pathway, making them potential contributors to crop Zn biofortification. Key unknowns remained: how much Zn this pathway provides, the molecular mechanism of fungal-to-plant Zn transfer, and how AM fungi affect Zn bioavailability for human nutrition. Using radioactive Zn and specialised soil hyphal compartments, we showed that AM fungi contributed up to a quarter of shoot Zn in three crop species. Transcriptomic analysis of Medicago truncatula roots led to the first identification and characterisation of a ZIP transporter likely responsible for Zn uptake between fungus and plant. We have since extended this work to human nutrition, assessing how AM fungi affect the anti-nutrient phytic acid and Zn bioavailability in food crops. AM fungal inoculation led to increased Zn bioavailability in sorghum and bread wheat, but reduced bioavailability in a number of other crops.