Changes in Mineral Profile of Portulaca oleracea L. Under Foliar Treatment with Sodium Selenate

The mineral composition of edible plants often changes as a result of selenium biofortification, which affects plant species tolerance and adaptability to Se supply, as well as nutritional value. To reveal the peculiarities of macro- and microelements in root–leaf–seed distribution in wild purslane foliar treated with sodium selenate (50 mg L−1), 23 chemical elements were determined in control and Se-fortified plants using ICP-MS. Against the backdrop of plant growth stimulation, the concentration of macroelements did not change significantly in roots, increased in leaves due to high Ca and Mg levels, and decreased in seeds (from 16,959 to 11,997 mg kg−1 d.w.). A decrease in Fe, Mn, Cu, Zn, and Co was recorded in leaves (1.37–1.69 times) and seeds (1.38–3.07 times), with insignificant changes in mineral profile in roots. Accordingly, the root–leaf Transfer Factor (TF) of Ca and Mg increased while leaf–seed TF decreased. Root–leaf TF of K, Na, and P decreased due to Se supply. No changes were recorded for Si TFs or for Cu leaf–seed TF. On the other hand, the TF increased for B (root–leaf) and Zn (leaf–seed). Changes in potentially toxic element concentrations due to Se supply showed negative correlations with the atomic weight of elements (roots r = −0.886; leaves r = −0.931; p < 0.001, and seeds r = −0.867; p < 0.005). Similar relationships for several other plant species (Artemisia annua L.; Allium ursinum L.; Brassica rapa subsp. rapa L.) and a lack of corresponding correlations in other crops (Allium sativum, Allium cepa, Brassica oleracea) indicate the need for further mineral profile investigations in Se-fortified plants.