Environment relevant concentrations of lithium influence soybean development via metabolic reprogramming

The production of lithium (Li) has attracted global attention in recent years due to unprecedented demand in modern industry. The effect of lithium exposure on plant sub cellular distribution, mineral homeostasis and root metabolomic is rarely reported. Current study shows that lethal concentration on physiological and photosynthetic indicator was measured to be 146–177 mg kg⁻¹. The higher mobility of Li was observed in shoots (383 fold) relative to the root (4.2 fold). Li was mainly deposited in vacuole (103–320%) followed by cell wall (78–203%), mitochondria (46–303%), nucleus (21–298%) and plastid (26–298%), which suggested that both compartments (vacuole and cell wall) act as crucial defensive barriers against Li stress in soybean. Additionally, high concentration of Li (100 and 200 mg kg⁻¹) in soil dramatically altered and down-regulated the specific root metabolites in ABC transporters, ascorbate metabolism, aminoacyl-tRNA biosynthesis and pentose phosphate pathways leading to the poor soybean growth and development. Li exposure at 100–200 mg kg⁻¹ decreased Ca ∼27–43% and Mg ∼25–71% relative to control. These results provide valuable information for mechanistic understanding the biological impact of Li on plant physiology and root metabolites; such understanding pave a way forward for execution of emerging Li issues in agriculture.