Metallo-adaptive response: a unique survival strategy of plants under genotoxic stress

The sedentary nature of a plant’s lifestyle has lead to the evolvement of different strategies to minimise the effects of various genotoxic environmental agents. One of such strategies is adaptive response (AR) that plants develop inherently to maintain their genome integrity under stress. The concept of AR has emerged as a novel means of enhancing plant tolerance to different environmental stresses once exposed to low levels of certain genotoxins. It is a new challenge for the next generation of plant biology where AR, induced by the ‘low-concentration zone’ of the full dose–response range, holds a central role. The present paper discusses the historical background of the AR concept along with the reports of adaptive responses induced by different metals and heavy metals against various genotoxic challenges in plant systems. The responses to high-dose stress have been widely studied in the past century and now it is time to focus on the low-dose stress responses, which can improve plant’s performance under stress, enhance plant productivity and protect plant cells against such unfavourable conditions.