Ionomic responses of wild and transgenic nicotiana langsdorffii plants exposed to heat stress

Plants are composed of chemical elements, which uptake, distribution and accumulation are controlled by genetic and environmental factors. Particularly, plants face adverse or limiting conditions by activating a complex system of physiological and metabolic responses. High temperatures, together with other stress factors induced by global climate change, may significantly affect the growth and development of plants; heat stress conditions showed to delay plant’s growth, damage its cell membranes, increase transpiration and reduce the opening of the stomata. In this work, Nicotiana langsdorffii plants, wild and transgenic for the Agrobacterium rhizogenes rol C and rol D gene and the rat glucocorticoid receptor (GR) gene, were exposed to heat stress. The responses of the transgenic plants to the abiotic stresses were assessed by the analysis of the plant ionomic profile, the metabolomic data and the phytormonal profile (1,2). Simultaneous determination of 12 elements was carried out by ICP-MS equipped with a collision/reaction cell (ICP-ORS-MS). WT, Rol D and Rol C plants showed higher changes both in the ionomic and in the metabolic profile, suggesting that these genotypes could be more affected by heat stress exposition. On the contrary GR plants showed almost unchanged values of many elements and organic compounds (including phytohormone and lipids) indicating that this genetic modification could provide a higher plant resistance toward heat stress. Statistical analysis permitted to highlight the main significant differences among the metabolic responses of the examined genotypes