Scientists in Australia claim to have developed a reliable way to "switch off" unwanted genes in plants. Coffee and tea without caffeine and nuts which do not cause allergies may be part of the future as a team from CSIRO Plant Industry in Canberra report that they have discovered a refined technique to "silence" the genes. The new method will also be used to discover the unknown functions of many genes by examining the effect on a plant if one gene at a time is silenced. Most of the GM crops developed so far have had genes added rather than silenced but there are many genes in plants that scientists believe could be beneficially switched off. Details of the study are report in the latest issue of Nature magazine.