University of Copenhagen researchers pave the way for a new protein source
Photo by Tim: https://www.pexels.com/photo/yellow-rapeseed-field-selective-focus-photography-97778/
A research team from the Department of Plant and Environmental Sciences at the University of Copenhagen has identified the proteins that help store bitter substances in the seeds of a model goose bait, which is closely related to the rapeseed plant.
The new research result has just been published in the scientific journal Nature.
Rapeseed is grown on more than 200,000 hectares in Denmark and is used for rapeseed oil and as a protein supplement in animal feed, but not as food for humans. This is because the rapeseed plant has a high content of bitter defence substances, which the plant uses to avoid disease attacks and herbivores, and which at the same time makes it inedible to humans.
The development and knowledge gained can be used to remove the proteins and bitter taste from the rapeseed plant, which has huge potential as half of the EU’s locally grown plant proteins already come from rapeseed.
“The climate crisis dictates that we should eat less meat and more plants, and here rapeseed plant has great potential as a new source of plant protein in the green transition. Our latest research results bring us a decisive step closer to making full use of rapeseed,” says Professor Barbara Ann Halkier, who led the research.
The bitter defences in rapeseed are called glucosinolates and are best known as the strong flavour in wasabi and mustard. The so-called rapeseed cake, which is the remains of the seeds after the rapeseed oil has been squeezed out, has only been able to be used in limited quantities as feed for pigs and chickens, even though the protein content is a staggering 30-40 per cent.
The fact that the researchers have now identified the three proteins in the plant that are responsible for transporting the bitter substances into the plant’s seeds means that they can prevent the accumulation of bitter defence substances in the seeds. This is done by precisely removing these three proteins from the plant using a technology called ‘transport engineering’. In this way, the defence substances are still present in all other parts of the plant, so that it can continue to defend itself against its enemies. But the bitter, unhealthy substances are gone.
“Plants have their roots well planted in the soil and cannot just move when there is danger, and therefore they need to produce a wealth of defence substances against disease attacks and herbivores. With our discovery, we have found a way to turn off the bitter substances in the seeds,” says Dr. Deyang Xu, first author of the new study.
The researchers have so far shown that their method works in the model plant goosebait (Arabidobsis thaliana), which is closely related to the rape plant.
“The next task is to show that we can transfer our result from goose bait to rapeseed plant, and we are currently working on this,” says Dr. Deyang Xu.