Towards a System Based Understanding of Plant Metal Hyperaccumulation.

Heavy metals hyperaccumulation occurs in a unique group of plants species termed as ‘metal hyperaccumulator’. Here, we review the molecular genetics, physiological, biochemical, ultrastructural and biophysical studies that have been performed on a variety of metal hyperaccumulator plants to discover the mechanisms responsible for their hyperaccumulation traits. Hyperaccumulation in hyperaccumulator plants involves a combination of molecular genetic mechanisms, metabolic and antioxidant systems as well as macromolecular and structural stabilizing processes. We propose that a systems-biology approach coupled with multivariate data analysis is best suited to unraveling the mechanisms responsible for plant hyperaccumulation, as well as their integration with one another. This is of particular relevance to molecular biological engineering strategies for improving plant tolerance and accumulation in important crop species.