Effect of heat stress on the ionomic profile of <i>Nicotiana langsdorffii</i> wild-type and mutant genotypes

<p>Possible changes in the ionome of <i>Nicotiana langsdorffii</i> wild-type and transgenic specimens following heat stress have been explored, considering both variations in the total concentration of 28 major and trace elements and their root/aerial part partitioning. In order to reveal the statistically significant effects, the natural variability was evaluated by the analysis of 10 individual specimens for each genotype. It was found that heat stress affects the plant ionome in a complex way, depending on the element and the genetic modification. A significant decrease in the total concentration was observed for several elements (e.g. Fe and Zn), whereas fewer elements (e.g. Ca and Mg) showed the opposite trend. The heat stress also affected the elemental distribution within the plants, determining accumulation in roots (e.g. Mo, P and Zn in transgenic plants) or in the aerial part (e.g. K) and indicating an altered efficiency of ion transport or uptake processes, respectively. Finally, analytical data for the heat stress were merged with those previously obtained for chemical and water stresses and analysed by multivariate analysis, making it possible to display the different ionomic signatures of each stress and suggest suitable indicators for plant biomonitoring studies.</p