Orange trees that bear fruit in just one year have been created by researchers in Spain, the New Scientistt reports this week. In general, citrus plants take at least 6 years to reach maturity and produce fruit. José Martínez-Zapater from the Universidad Autónoma de Madrid and colleagues accelerated the development of the citrange tree, a close relative of the orange. The researchers took a gene from thale cress, also known as Arabidopsis. The gene, called APETALA1, switches on at the appropriate time in development of Arabidopsis, and signals to the plant to start producing flowers. When the researchers put the gene into citrange plants so that it was active all the time, the plants rushed through their juvenile phase and matured early, producing fruit at the end of their first year. Martínez-Zapater commented that the technique probably will not be that useful in orange production because the year-old trees cannot support the weight of the fruit that they produce. They also take longer to reach full size. "But it will be a very useful tool for genetic improvement." The fast developers will enable crosses to be made between different citrus species without each hybrid taking years to mature. This might include plants that are resistant to viruses, or oranges that are smaller, and easier to peel. The authors of the study further noted that once desirable plants have been produced, apetala1 could be removed, so that the plants eventually grown by farmers would not contain any foreign genes.