In Arabidopsis thaliana cadmium affects growth of the primary root by altering SCR expression and auxin-cytokinin crosstalk

Cadmium is a toxic metal in our environment. Bruno et al. explored cadmium-mediated root-growth inhibition using the model plant Arabidopsis thaliana. Cadmium affects root growth longitudinally by reducing root meristem cell number and radially by controlling the number and width of stele cells. The authors showed that misexpression of the trasncription factor SCARECROW (SCR) occurs due to cadmium toxicity in roots. Two major hormones – auxin and cytokinin – are crucial for root developmental processes. Studies with auxin responsive marker (pDR5::GFP), auxin transporters (PIN1, 2, 3 and 7) and cytokinin response marker (TCSn::GFP) revealed that cadmium induces down-regulation and mislocalization of PIN proteins as well as altered auxin maxima in the root tip. Furthermore, an increased signal of TCSn::GFP is detected due to cadmium. This work provides a comprehensive overview of how cadmium alters root development from the physiological and molecular perspectives. Front. Plant Sci. 10.3389/fpls.2017.01323