Cd-induced Cu deficiency responses in Arabidopsis thaliana: are phytochelatins involved?

Cadmium (Cd) exposure can disturb the homeostasis of essential elements. In Arabidopsis thaliana, Cd induces a squamosa promoter binding protein-like 7 (SPL7)-dependent Cu deficiency response. We investigated how Cd induces a Cu deficiency response.

Toxicity responses of Cu and Cd: the involvement of miRNAs and the transcription factor SPL7.

Background: MicroRNAs are important posttranscriptional regulators of gene expression playing a role in developmental processes as well as in stress responses, including metal stress responses. Despite the identification of several metal-responsive miRNAs, the regulation and the role of these miRNAs and their targets remain to be explored. In this study, miRNAs involved in the response to Cd and Cu excess in Arabidopsis thaliana are identified.

Hydrogen Peroxide, Signaling in Disguise during Metal Phytotoxicity.

Plants exposed to excess metals are challenged by an increased generation of reactive oxygen species (ROS) such as superoxide ([Formula: see text]), hydrogen peroxide (H2O2) and the hydroxyl radical ((•)OH). The mechanisms underlying this oxidative challenge are often dependent on metal-specific properties and might play a role in stress perception, signaling and acclimation. Although ROS were initially considered as toxic compounds causing damage to various cellular structures, their role as signaling molecules became a topic of intense research over the last decade.

MicroRNAs in metal stress: specific roles or secondary responses?

In plants, microRNAs (miRNAs) control various biological processes by negatively regulating the expression of complementary target genes, either (1) post-transcriptionally by cleavage or translational inhibition of target mRNA, or (2) transcriptionally by methylation of target DNA. Besides their role in developmental processes, miRNAs are main players in stress responses, including metal stress responses. Exposure of plants to excess metal concentrations disturbs the cellular redox balance and enhances ROS accumulation, eventually leading to oxidative damage or signaling.

A mutant of the Arabidopsis thaliana LIPOXYGENASE1 gene shows altered signalling and oxidative stress related responses after cadmium exposure.

Lipoxygenases (LOXes, EC 1.13.11.

Understanding the development of roots exposed to contaminants and the potential of plant-associated bacteria for optimization of growth.

Background And Scope: Plant responses to the toxic effects of soil contaminants, such as excess metals or organic substances, have been studied mainly at physiological, biochemical and molecular levels, but the influence on root system architecture has received little attention. Nevertheless, the precise position, morphology and extent of roots can influence contaminant uptake. Here, data are discussed that aim to increase the molecular and ecological understanding of the influence of contaminants on root system architecture.

Cadmium stress: an oxidative challenge.

At the cellular level, cadmium (Cd) induces both damaging and repair processes in which the cellular redox status plays a crucial role. Being not redox-active, Cd is unable to generate reactive oxygen species (ROS) directly, but Cd-induced oxidative stress is a common phenomenon observed in multiple studies. The current review gives an overview on Cd-induced ROS production and anti-oxidative defense in organisms under different Cd regimes.