In a paper published in the journal PLOS Pathogens, lead author Dr Linda Johnson describes the tactic used by an endophyte to extract a vital nutrient, iron, from its ryegrass host.
Paddocks of flourishing ryegrass are a typical New Zealand scene.
Hidden within the grass, however, lies an invisible helper, an endophytic fungus that protects pastures from being devastated by unwanted pests, ultimately increasing pasture production and persistence.
The endophyte produces a small molecule, known as a siderophore, which grabs and binds strongly to iron, an element essential to both the grass and the fungus.
This iron-grabbing trick is widespread among fungi, with common human fungal infections such as thrush and athlete’s foot depending on the iron they quietly filch from us.
However, it is the fascinating result of experimentally deleting the iron-grabbing siderophore gene from an endophytic fungus that led to its publication in PLOS Pathogens.
“Eliminating the siderophore caused major problems for both the fungal endophyte and the host grass plant,” Johnson, the science team leader for plant-fungal interactions, said.
“The usual tightly controlled, synchronous growth of the fungus inside the ryegrass became deformed and unregulated. The host plants were stunted and in extreme cases both the fungus and host plant died.”
This is the first report that siderophores are essential to the mutually beneficial relationship between ryegrass and endophyte.
The relationship is crucial for NZ agriculture.
More? www.agresearch.co.nz
