Genetically engineered dandelion can ooze more rubber India News and Travel Times Provides India-centric and other News and Features

Scientists have developed a genetically engineered dandelion that produces more latex that could be used in gloves, tyres and drugs. For thousands of years, most of the world's rubber has come from tropical rubber trees. A diagonal cut in the trunk allows the white latex to drip into hanging cans, which can then be harvested and eventually turned into a variety of materials. But, natural rubber contains trace amounts of biological impurities. For car tyre makers, those impurities give vulcanised rubber a give and elasticity they can't get anywhere else. For some hospital workers, however, those same impurities can trigger life-threatening allergic reactions. Synthetic or petroleum-based rubber typically has fewer impurities than natural rubber, which makes it ideal for applications like allergy-free gloves. But, according to a report in ABC Science, dandelion-derived latex has both the elasticity of natural rubber but lacks the allergens, making it an ideal alternative to rubber tree latex. Unfortunately, dandelion-derived latex is also difficult to obtain. Because dandelion latex transforms from a liquid to a solid on contact with the air (known as polymerisation), turpentine and naphtha are usually required to chemically extract the latex from the shredded remains of Russian dandelions. To eliminate polyphenol oxidase, the enzyme responsible for the phase change, German scientists engineered a special virus. Once inside, the virus deleted the offending genetic sequence from the Russian dandelion's DNA. Pop the head off an infected dandelion, and the latex begins to flow freely. Eliminating polymerisation means dandelion latex can be harvested using a low-speed centrifuge, a much easier and cheaper alternative than chemical solvents. It also means up to five times the amount of rubber can be harvested than with chemical extraction. "We have identified the enzyme responsible for the rapid polymerisation and have switched it off," said Dr Dirk Prufer, a scientist at Fraunhofer Institute in Munich, Germany, who is developing the technology. "If the plants were to be cultivated on a large scale, every hectare would produce 500 to 1000 kilograms of latex per growing season," he added.