A common response to common danger? Comparison of animal and plant signaling pathways involved in cadmium sensing

Abstract

Exposure to cadmium results in disturbances in cell homeostasis in all living organisms. The first response to stress factors, including cadmium, is activation of signal transduction pathways that mobilize cell defense mechanisms. The aim of this review is a comparison between the signaling network triggered by Cd in plants and animals. Despite differences in the structure and physiology of plant and animal cells, their cadmium signal transduction pathways share many common elements. These elements include signaling molecules such as ROS, Ca2+ and NO, the involvement of phospholipase C, mitogen-activated protein kinase cascades, and activation of transcription factors. Undoubtedly, both animals and plants also possess specific signaling pathways. In case of animals, Wnt/β-catenin, sonic hedgehog and oestorgen signaling are engaged in the transduction of cadmium signal. Plant specific signal transduction pathways include signaling mediated by plant hormones. The role of ethylene and jasmonic, salicylic and abscisic acid in plant response to cadmium is also discussed.

Chance and predictability in evolution: The genomic basis of convergent dietary specializations in an adaptive radiation

“…Although the downregulation pattern observed in specialist Dysdera could be the result of a direct stress‐induced perturbation of gene expression caused by the high concentration of heavy metals supplied in a woodlouse‐rich diet, they might actually be part of an adaptive biological response to excrete metals or other toxic substances more efficiently, thus avoiding their assimilation (Van Straalen & Roelofs, ). Consistent with this hypothesis, we observed concordant DE patterns in some MAP kinase pathway members, which participate in an important stress‐activated/immune response cascade (Chmielowska‐Bąk & Deckert, ), and in some ubiquitin ligases, which, among other functions, are involved in the inhibition of cell growth and cycle arrest in response to DNA damage (Cao & Yan, ). The adaptive response in specialists would consist of downregulating a set of genes to keep gut epithelial cells in a semi‐degenerated functional and structural state that allows enhanced accumulation of heavy metals in granules and very fast and effective intestinal exfoliation and regeneration.…”

The toxic Doppelganger: on the ionic and molecular mimicry of cadmium.

“…These lesions lead to membrane leakage, disturbed ion homeostasis, inactivation of enzymes, and increased rate of mutations (Scandalios, 2002). The reactive oxygen species generated in response to cadmium are also engaged in various signaling events (Chmielowska-Bąk & Deckert, 2012). The Cd-dependent over-production of ROS can result from disturbances in antioxidant systems, increased activity of NADPH oxidase, and alterations of mitochondria (Garnier et al, 2006;Romero-Puertas et al, 2007;Gzyl et al, 2009;Ognjanović et al, 2010;Chen et al, 2011;Chou et al, 2012).…”

NADPH oxidase is involved in regulation of gene expression and ROS overproduction in soybean (Glycine max L.) seedlings exposed to cadmium

“…These toxicity mechanisms result in alterations in photosynthesis, imbalances in ion homeostasis, impeded cell division, growth inhibition, and eventually cell death [3,4]. One of the most common reactions to Cd observed in plants and animals is accumulation of reactive oxygen species (ROS), which include hydrogen peroxide (H 2 O 2 ), hydroxyl radical ( • OH), superoxide anion (O 2 •− ) and singlet oxygen ( 1 O 2 ) (reviewed in [5]). There are several sources of ROS in Cd-stressed plants, including alterations in mitochondria functioning, depletion of the antioxidant system, and increased activity in the membrane-bound, O 2 − -producing enzyme NADPH oxidase, with the latter being the suggested main source of ROS in response to short-term Cd stress [6].…”