A model system to study the effects of elevated CO<inf>2</inf>on the developmental physiology of roots: The use of Arabidopsis thaliana
Crookshanks M., Taylor G., Dolan L.
Three developmental changes were observed in the roots of Arabidopsis thaliana (Columbia) when shoots were exposed to elevated CO 2 (i) The allometric coefficient, k, was enhanced significantly (P < 0.001), (ii) primary root length and root extension rate were enhanced (P < 0.001). Accelerated cortical cell expansion contributed to this effect and was associated with increased cell wall extensibility, measured as % plasticity. (III) Lateral root formation and extension were also increased in elevated CO 2 (P < 0.05). These results illustrate that root growth and structure was altered following exposure to elevated CO 2 . The changes observed suggest that Arabidopsis provides a useful model which should, in future, be amendable to study using appropriate mutants allowing the genetic basis of the responses to be identified.