Arabidopsis thaliana: Wonder-weed de-coded
A major milestone in genetics is announced on 14 December in the Journal 'Nature' with the first complete sequencing of the plant genome 'Arabidopsis thaliana'. Scientists are hailing the news as the beginning of a new paradigm in biology, marking the ability to move from empirical observation of genetic mechanisms towards understanding and rationalising what genes do at the molecular level. 'This knowledge has profound significance for mankind and our quest to balance food and the protecting the environment,' said Mike Bevan, of the John Innes Centre in Norwich (UK), who was one of the European project coordinators. Press conferences have been held across the world to announce the result, which scientists hope will provide the first key to unlocking the function of genes in all plants: The pioneering work results from nearly ten years of international collaboration between Europe, the USA and Japan, kicked off by the European Commission in 1991. In this time the European Commission has contributed some 26 million euro to the research effort. Around 114 researchers from 15 countries collaborated to analyse some 115 million base pairs in nearly 26,000 genes on the plant's five chromosomes. Nature magazine will release the sequence on a CD-Rom with the special A. thaliana issue. The German Centre of Environment and Health, which completed the final stages of the research - putting the sequence into a readable format - has created a dedicated website from which the code will be freely available to the scientific community. The move is unprecedented. 'This is the largest set of genes to be released at once,' said Professor Francis Quétier of French project partner Genoscope. With the complete 'text' of the plant's DNA now available, the next challenge will be deciphering it. 'We don't know what parts these genes apply to,' says Professor Werner Mewes of the Max Planck-Institute for Biochemistry. 'Understanding life is the greatest and most important challenge to science. It's not the man on the moon. It's life. If we understand the basis of Arabidopsis we understand the basic mechanisms for all plants.' 'The next challenge will be to understand what these genes do,' agreed Dr Marc Zabeau, of the Gent University of biotechnology. 'One third of them are novel genes that we have never seen before...Over 100 years we have identified barely five per cent of what genes do in a plant.' European efforts in this area are already underway, with the European Commission funding two new projects through its Quality of Life and Management of Living Resource programme. The projects 'EXOTIC' (Exon trapping insert consortium) and 'REGIA' (Regulatory gene initiative in Arabidopsis) 'will play a key part in the 'genomics revolution' by linking the Arabidopsis genome to a precise description of gene activity,' says the Commission. Another project dubbed 'ECCO (European cell cycle consortium)' which aims to isolate and study genes controlling cell division, is also planned. Altogether, the European Union will contribute some 14 million euro to these projects. Until now, botanists have considered A. thaliana as no more than a common weed. This December's announcement will change that affirmed, Carina Dennis and Christopher Surridge in an editorial to Nature: 'In 1777 the British botanist and apothecary William Curtis described A. thaliana...as a plant of 'no particular virtues or uses'. With today's publication of its genome it can justifiably claim to have risen to among the most significant plants in the kingdom.' Despite its lowly status, scientists decided to study A. thaliana because it has a short genome in comparison to other plants. It could therefore be deciphered more quickly, and because it is likely to share the same genetic code for 'plant-ness' common to all plants, it could provide important knowledge that could be applied to agricultural crops and possibly to genetic processes in animals as well. It also grows quickly, allowing scientists to study variations between generations more easily than most plants and it is found in all sorts of climates, from the equator to the Arctic. Understanding how it is able to do this could have massive impacts on the way agriculturists select varieties of plants to grow in different conditions. Now A. thaliania will provide the basis to develop tools not only for genetic manipulation but also to improve traditional selective breeding techniques. The choice on how the knowledge gained from A. thaliana will be used will depend on what society finds acceptable, says Dr Marc Zabeau. And while much of the human genome has been decoded, it is still in a working draft, which is far less accurate than the completed plant sequence, he adds. The news will have ramifications for sustainable and environmentally sound agriculture, for food quality and for the conservation of biodiversity, concludes Dr Zabeau. 'The project proves again the value of international scientific cooperation when it is organised at the European level,' said Research Commissioner Philippe Busquin. Professor Werner Mewes agreed on the importance of this aspect of the work: 'I think it's a milestone. It's not that it's been done with European money but that it's a truly European project,' he said.