Dandelions to rescue rubber industry

Aachen, Germany - Anyone who has picked dandelions as a child will be familiar with the white liquid that seeps out of the stalks as you break them off. Viscous, sticky  and a much sought-after material: natural latex. Around 30,000 everyday products contain natural rubber, everything from car tyres, catheter tubes, latex gloves to tops for drinks bottles.

However, a fungus is now creating concern for rubber cultivators in South America, where the infection is now so widespread that large-scale cultivation has become virtually impossible. The disease now also appears to have taken root in Southeast Asia's rubber belt, which provides most of the world's natural rubber supply.

Fungicides still provide at least temporary protection. But if the fungus disease was to reach epidemic proportions, chemical crop protection would be rendered useless experts fear that the natural latex industry could collapse if that were to happen.

Researchers are therefore turning to other sources such as the Russian dandelion. Germans, Russians and Americans produced rubber from this plant during the Second World War. Once it is cut, latex seeps out, albeit difficult to use as it polymerises immediately.

Scientists from the Fraunhofer Institute for Molecular Biology and Applied Ecology IME in Aachen have now come a step nearer to large-scale rubber production from dandelions. In particular, they have identified the enzyme responsible for the rapid polymerisation and have switched it off by genetically modifying the dandelion in the lab.

"If the plant is cut, the latex flows out instead of being polymerised. We obtain four to five times the amount we would normally," said prof. Dr. Dirk Prüfer, head of department at the IME. "If the plants were to be cultivated on a large scale, every hectare would produce 500 to 1000 kilograms of latex per growing season."

The researchers' next challenge is to cultivate the optimised plants using conventional breeding techniques. In around five years, Prüfer estimates, they may well have achieved their goal. In any case, he added, the dandelion is not just suitable for rubber production: the plant also produces substantial quantities of inulin, a natural sweetener.