A step towards drought-resistant crops

As global warming appears to be taking its toll and with German farmers alone predicted to lose up to 80 per cent of their crops due to the Europe-wide heatwave this summer, scientists from the University of Bonn in Germany claim to have identified a gene which makes plants more resistant to a shortage of water.

As global warming appears to be taking its toll and with German farmers alone predicted to lose up to 80 per cent of their crops due to the Europe-wide heatwave this summer, scientists from the University of Bonn in Germany claim to have identified a gene which makes plants more resistant to a shortage of water.

The scientists say they have constructed a variety of plant in which the drought gene was frequently deployed and can therefore withstand aridity considerably longer than its natural form in the wild. On a long-term basis the scientists hope that they may contribute to developing crops which are resistant to drought.

The results have been published in the latest edition of The Plant Journal.

The discovery came following the observation of the 'resurrection plant'. In droughts this South African plant is said to shrivel up into a brownish mass, but when after weeks or months the rain comes, what looked like dead leaves become green again within a few hours. The plant can lose up to 95 per cent of its water reserves without being harmed, say the scientists.

The plant is genetically programmed so that a whole series of genes is only used in drought periods, with others being shut down completely. "By looking at which genetic features are mainly active during periods of drought we are attempting to understand which molecular processes make the plant so hardy," explained Professor Dorothea Bartels of the University of Bonn''s Botanical Institute.

The researchers found a gene which is very similar to that of the resurrection plant's in mouse-ear cress - Arabidopsis thaliana - which is indigenous to Germany and the scientists describe as the plant geneticists' equivalent of the laboratory mouse, since it is a model organism which is simple to breed and genetically easy to modify, whose genetic pattern has been completely sequenced.

The drought gene ensures that the plant can cope better with specific toxins which increase when the plant is hit by drought stress. It contains the structural plan for the detoxification enzyme aldehyde dehydrogenase (ALDH).

The Bonn scientists modified the ALDH gene of the mouse-ear cress to ensure that it kicks in much more frequently. The scientists reported that the genetically modified plants not only produced more ALDH, they also survived substantially longer droughts, even where the salt concentration was higher than normal, lasting up to 16 days without water compared to 12 days by their natural form.

On a long-term basis the scientists hope that these findings might contribute towards developing drought-resistant varieties of maize, wheat or soya.

According to a study by the International Water Management Institute, by 2025 one third of the world's population will be living in arid regions. And although it is traditionally the poorer countries which are hit, even the industrialised countries are no strangers to this development as this year alone may well prove.

As such it seems highly possible that, although controversial from a GM aspect, without developments of this kind to help crops evolve to meet the changing nature of our climate, prices for what are now considered everyday, basic commodities could climb to comparatively exorbitant levels, with knock-on effects to be expected for the majority of the world's food and drink sector.

For further information contact Dorothea Bartels.