Molecular mechanisms of metal hyperaccumulation in plants

Abstract

Contents Summary 759 Hyperaccumulation: the phenomenon 759 Macroevolution of hyperaccumulation 760 Microevolution of hyperaccumulation: variation within hyperaccumulator species 760 Genetic analysis of trace metal accumulation and tolerance 761 Mechanisms of trace metal accumulation 762 General discussion and research perspectives 769 Acknowledgements 772 References 772 Summary Metal hyperaccumulator plants accumulate and detoxify extraordinarily high concentrations of metal ions in their shoots. Metal hyperaccumulation is a fascinating phenomenon, which has interested scientists for over a century. Hyperaccumulators constitute an exceptional biological material for understanding mechanisms regulating plant metal homeostasis as well as plant adaptation to extreme metallic environments. Our understanding of metal hyperaccumulation physiology has recently increased as a result of the development of molecular tools. This review presents key aspects of our current understanding of plant metal – in particular cadmium (Cd), nickel (Ni) and zinc (Zn) – hyperaccumulation.

Tolerância de mamona a zinco avaliada por fluorescência de clorofila e nutrição das plantas

“…Geralmente, a disponibilidade metabólica e a translocação de metais são limitadas pelo sequestro no vacúolo das células radiculares (Verbruggen et al, 2009). O acúmulo de metais nas raízes é um mecanismo importante que o sistema radicular pode contribuir para a tolerância de plantas a metais.…”

Sequencing of the genus Arabidopsis identifies a complex history of nonbifurcating speciation and abundant trans-specific polymorphism

“…Several such categories were found (Supplementary Table 2). For example, genes divergent in A. halleri were overrepresented in the 'heavy metal-associated domain' category, consistent with metal hyperaccumulation in A. halleri 30,31 . Less obviously, genes divergent in A. lyrata were overrepresented in the 'circadian rhythm' category, perhaps reflecting the wide latitudinal distribution of this species and adaptation to different day lengths.…”

Role of transpiration in arsenic accumulation of hyperaccumulator Pteris vittata L.

“…And, on the other hand, low As exposure greatly increased the transpiration of P. vittata, similar to another As hyperaccumulator Pteris cretica (Lee and Lee 2011). It requires further investigation in that the evolution of As accumulation is related to water stress, similar to the inadvertent uptake theory of hyperaccumulation, which is that hyperaccumulation resulted from inadvertent uptake if the accumulated elements are chemically similar to essential nutrients and plant populations evolve more efficient uptake and translocation systems for these nutrients (Cappa and PilonSmits 2014;Pollard et al 2014;Verbruggen et al 2009). The measured and implied As amount.…”