Seed biopriming with Paraburkholderia phytofirmans PsJN reprograms micronutrient homeostasis and limits nickel translocation in “Micro-Tom” tomato

Nutrient balance and interaction between macro- and micronutrients are vital for plant development, yet this equilibrium is frequently disrupted by the accumulation of residual nickel (Ni) from prolonged fertilizer application. As plant growth-promoting bacteria offer sustainable ecological solutions, this study investigated the effects of biopriming Micro-Tom tomato seeds with Paraburkholderia phytofirmans PsJN under chronic and acute Ni exposure. Using Flame Atomic Absorption Spectrometry (FAAS), we analyzed microelements in roots, leaves, and ripe fruits of non-primed and bioprimed plants. The results demonstrate that biopriming is associated with a shift in the plant’s ionomic response to stress. Bioprimed plants showed increased Ni retention in the root system compared to non-primed plants, reducing Ni translocation to reproductive organs. Correlation analysis revealed altered patterns of nutrient association. Bioprimed plants exhibited a tendency toward co-accumulation and retention in roots, while ion balance in leaves and fruits appeared more regulated. These findings suggest that P. phytofirmans PsJN may contribute to improved nutrient homeostasis under Ni stress.