Scientists turn to weeds to feed the world

Using thale cress, a common weed that is in the same family as cabbage and oil seed rape, researchers at the University of Manchester have identified a protein that helps plants ‘track’ the environment and increase their capacity to photosynthesise (capturing light energy through the leaves which enables them to grow).

They found that disruption of the thale cress' genetic structure meant it was less able to respond to the changes in environment. Some plants, including important crops such as wheat, rice and barley, are less able to track their environment and are thus unable to cope with environmental changes.

Dr Giles Johnson and his team believes their investigation may help to develop plants that cope better with changes in the environment, possibly enabling greater crop yields in the face of global warming.

Dr Johnson said: “Seed production is 60 per cent lower in plants that are unable to cope with environmental change, which you can translate into a farmer’s yield”.

The research team hopes to be able to help plants respond to changes in their environment by the use of selective breeding or genetic modification (GM), thereby enabling crop yields to increase, especially in vulnerable land.

Dr Johnson explained: “Over the last 200 years, industrial society has transformed the atmosphere of our planet, increasing CO2 concentration by 50 per cent. Climates are becoming warmer but, crucially, more unstable with increasing frequencies of extreme weather events such as droughts and heat waves – it is this variability of climate that poses most threat to agriculture. Even short periods of extreme weather can trigger crop failure.

“If we wish to secure food production, we urgently need to breed plants with an increased ability to tolerate change in their environment,” he said.

He said the team will now study the genetic basis of the process further to find out how the trait of responding to environmental changes can be transferred to other plants.

Using selective breeding or GM to breed the ability to respond to environmental changes into crop plants represents a big scientific challenge. And Dr Johnson also acknowledges there may be other challenges concerning GM.

While it remains controversial, Dr Johnson had this to say about the team’s findings: “Climate change means increasing extreme weather; meanwhile the world’s population is growing and the use of fertilisers is expensive in terms of production and oil costs. In addition, we need to make the crops give better yields because we haven’t got any more land to spread into. In fact we are losing agricultural land due to irrigation strategies that increase its salt content,” he explained.

Pointing to a recent Royal Society report which said that global productivity would need to double by 2050 to meet UN goals on poverty, Dr Johnson concluded, “Some members of the public have their misgivings about genetically modifying crops. However we urgently need to improve our crop yields and must use all the tools available to us.”