AUTHOR=Ferri Alessandro , Lancilli Clarissa , Maghrebi Moez , Lucchini Giorgio , Sacchi Gian Attilio , Nocito Fabio F. TITLE=The Sulfate Supply Maximizing Arabidopsis Shoot Growth Is Higher under Long- than Short-Term Exposure to Cadmium JOURNAL=Frontiers in Plant Science VOLUME=8 YEAR=2017 URL=https://www.frontiersin.org/journals/plant-science/articles/10.3389/fpls.2017.00854 DOI=10.3389/fpls.2017.00854 ISSN=1664-462X ABSTRACT=
The processes involved in cadmium detoxification in plants deeply affect sulfate uptake and thiol homeostasis and generate increases in the plant nutritional request for sulfur. Here, we present an analysis of the dependence of Arabidopsis growth on the concentration of sulfate in the growing medium with the aim of providing evidence on how plants optimize growth at a given sulfate availability. Results revealed that short-term (72 h) exposure to a broad range of Cd concentrations (0.1, 1, and 10 μM) inhibited plant growth but did not produce any significant effects on the growth pattern of both shoots and roots in relation to the external sulfate. Conversely, long-term (22 days) exposure to 0.1 μM Cd significantly changed the pattern of fresh weight accumulation of the shoots in relation to the external sulfate, without affecting that of the roots, although their growth was severely inhibited by Cd. Moreover, under long-term exposure to Cd, increasing the sulfate external concentration up to the critical value progressively reduced the inhibitory effects exerted by Cd on shoot growth, indicating the existence of sulfate-dependent adaptive responses protecting the shoot tissues against Cd injury. Transcriptional induction of the high-affinity sulfate transporter genes (