Lead (Pb) is reported to have negative effects on the biogeochemical behaviour of the plant growth. In recent years, the significance of rhizoremediation of heavy metals has been of great focus aiding in the development rates of plants under stressed conditions. The present study evaluated the physio-biochemical response of Pennisetum purpureum to different concentrations of Pb (II) viz., 0, 50, 100 and 150 mg kg⁻¹ in the form of lead (II) nitrate. The pre-characterized PGPR strain, Enterobacter cloacae - KU598849 was used to augment the plants. After Pb exposure for 45 d, parameters such as plant growth, lead accumulation, H₂O₂ content, MDA content, protein, proline content and antioxidant enzymatic activities were quantified. Results illustrated that increasing Pb concentration reduced the early growth, metal accumulation, protein content and affected physio-biochemical changes by causing oxidative damage in plants. Upon augmentation of the bacterial inoculum, the plants significantly resisted the toxic effects of Pb. Increased Pb bioaccumulation pattern was recorded in roots than shoots, were highest uptake was found to be 72 mg kg⁻¹ dry weight when exposed to 150 mg kg⁻¹ Pb concentration. Lead supplementation increased the activities of malonylaldehyde (MDA), superoxide dismutase (SOD), peroxidase (POX), ascorbate peroxidase (APX) and catalase (CAT) in P. purpureum. Bacterial bioaugmentation resulted in the reduction of the oxidative stress aided with reduced antioxidant enzyme activities indicating the minimization of the damages under stress.

据报道，铅（Pb）对植物生长的生物地球化学行为具有负面影响。近年来，重金属根际修复的重要性已成为关注在胁迫条件下植物生长速率的重要焦点。本研究评估了紫草对不同浓度的铅（II）硝酸铅（0、50、100和150 mg kg ^-1）的生理生化响应。使用预先定性的PGPR菌株阴沟肠杆菌-KU598849来增强植物。铅暴露45 d后，植株生长，铅积累，H ₂ O _2等参数含量，丙二醛含量，蛋白质，脯氨酸含量和抗氧化酶活性被定量。结果表明，铅浓度的增加会引起植物的氧化损伤，从而降低其早期生长，金属积累，蛋白质含量并影响其生理生化变化。在增加细菌接种量后，植物显着抵抗了Pb的毒性作用。根系中的Pb积累量高于枝条，当暴露于150 mg kg ^-1 Pb浓度时，最大吸收量为72 mg kg ^-1干重。铅补充增加malonylaldehyde的（MDA）的活动，超氧化物歧化酶（SOD），过氧化物酶（POX），抗坏血酸过氧化物酶（APX）和过氧化氢酶（CAT）象草。细菌的生物强化导致氧化应激的降低，同时抗氧化酶活性降低，这表明在压力下损害的最小化。