Structure and Functioning of Cluster Roots and Plant Responses to Phosphate Deficiency

The availability of soil phosphorus (P) frequently limits plant growth in both natural and agricultural systems. In agricultural systems the application of P fertilisers often leads to environmental problems. Moreover, readily available sources for P fertilisers will be depleted by the end of this century. To decrease our dependence on P fertilisers, a better understanding of the scavenging, uptake and use of P by plants is quintessential. In this respect, we may learn from plant species that form cluster roots (highly branched specialised root structures), as these are extremely effective in mobilising sparingly soluble soil minerals such as P. How do these roots achieve this? Is their effective P scavenging and uptake mainly a result of their different morphology, or are there also physiological or biochemical differences between cluster-rooted and non-cluster rooted species? The multidisciplinary workshop at which the papers in this volume were presented aimed at describing the state of the art on P scavenging, uptake and use, in species with and without cluster roots, by discussing these issues amongst a group of leading international scientists.