John Innes Centre makes breakthrough on poisonous grass peas

A team at the John Innes Centre is leading an international research collaboration aiming to find ways to breed a non-toxic variety of the grass pea.

One of the oldest known cultivated plants, the grass pea is rich in protein and resilient to both drought and flooding.

It is grown in Ethiopia, Eritrea, India, Bangladesh and Nepal as an "insurance crop" which survives when other crops fail and is considered safe to eat within a balanced diet.  

But its widespread cultivation is limited due to a toxin which can cause the disease neurolathyrism in malnourished people - inflicting irreversible paralysis.  

Using a new genome sequence of the plant, Norwich researchers have identified key biochemical steps that lead to the production of its notorious neurotoxin, known as ODAP.

Dr Anne Edwards of the John Innes Centre, one of the authors of the research published in the journal Nature Communications, said: "As we prepare for a future of increased climate change, we are going to need crops that can cope with drought, or flooding or inundations of salt water.

"Grass pea can survive such conditions better than other pulses, so now with the genetic resources we have, there is an opportunity to develop low-ODAP varieties which have agronomic traits adapted to local conditions around the world." 

The new genome sequence will allow researchers to use modern "gene-editing" techniques, alongside selective breeding methods, to develop varieties of grass pea with low or zero ODAP content.

They said this means the grass pea could be poised to make an important contribution to a more climate-resilient food system in the future. 

Glasshouse trials at the Norwich Research Park and field trials run by the International Centre for Agricultural Research in the Dry Areas (ICARDA) in Lebanon and Morocco, and by the Ethiopian Institute for Agricultural Research, are already under way to test the performance of low-ODAP grass pea lines crossed with local varieties.

Grass peas at the John Innes Centre (Image: Phil Robinson)