Regulatory networks of cadmium stress in plants

Abstract

During their life, plants have to cope with a variety of abiotic stresses. Cadmium is highly toxic to plants, water soluble and therefore promptly adsorbed in tissues and its presence greatly influences the entire plant metabolism. In this review, we focus on the signal pathways responsible for the sensing and transduction of the "metal signal" inside the cell, ultimately driving the activation of transcription factors and consequent expression of genes that enable plants to counteract the heavy metal stress.

Figure 1

Representation of the transduction pathway involved in Cd signaling. (A) Once entered the plant cell Cd induces ROS, responsible for the activation of MAPK kinase cascade. This, together with the activation of Ca-calmodulin system and stress-related hormones, converge regulating transcription factors in the nucleus. (B) In turn, transcription factors induce expression of Cd-detoxification responsible genes. JA (jasmonic acid); SA (salicylic acid); ROS (reactive oxygen species); MAK (mitogen-activated protein kinase); TF (transcription factor); PC (phytochelatin); PCS (phytochelatin synthetase); MT (metallothionein).