Getting to the root of plant evolution

Despite plants and vegetation being key to the Earth's ecosystem, little is known about the origin of their roots. However in new research that sheds light on how roots have evolved. The findings suggest that plant roots have evolved more than once, and that the characteristics of roots developed in a step-wise manner - with the central root organ evolving first. And the root cap subsequently coming later. Dr Sandy Hetherington and Professor Liam Dolan - both of Oxford's Department of Plant Sciences and Magdalen College Oxford, conducted a microscopic study of the oldest known plant ecosystem - the 407 million-year-old Rhynie chert. Dr Hetherington said: 'The level of preservation in the Rhynie chert is truly remarkable - it never ceases to amaze me that I am able to examine the cellular organisation of plants that were growing 407 million years ago. It provides an exceptional window into life on the terrestrial surface at that time.' The defining feature of modern-day plant roots is the meristem - a self-renewing structure that is covered by a cap at its apex.