Abstract

Plant-microbe interaction is a significant tool to tackle heavy metals problem in the soil. A pot trial was conducted to evaluate the efficiency of lead tolerant rhizobacteria in improving pea growth under Pb stress. Lead sulfate (PbSO₄) was used for spiking (250, 500, and 750 mg kg⁻¹). Results indicated that inoculation with Pb-tolerant PGPR strain not only alleviated the harmful impacts of Pb on plant growth but also immobilized it in the soil. PGPR in the presence of Pb at concentrations of 0, 250, 500 and 750 mg kg⁻¹, increased shoot and root lengths by 21, 15, 18% and 72, 80, 84%, respectively, than uninoculated control. Moreover, fresh biomass of shoots and roots were also increased by 51, 45, 35% and 57, 101, 139% respectively, at Pb concentrations of 250, 500 and 750 mg kg⁻¹. In addition, PGPR inoculation also reduced Pb concentration in the roots and shoots by 57, 55, 49% and 70, 56 and 58% respectively, than uninoculated control. So, PGPR proved to be an efficient option for reducing Pb mobility and can be effectively used for its phytostabilization.

Novelty statement

Lead (Pb) is highly noxious and second most toxic element in the nature having high persistence. It ranks 1^st in the priority list of hazardous substances and causes adverse effects after its entry into the living system. So, its remediation is inevitable. Plant growth promoting rhizobacteria (PGPR) possess the potential to not only survive under stressed environments, but also promote plant growth on account of their different plant growth promoting mechanisms.

Most researchers have worked on its bioaccumulation in plant body. This study however, used pea as a test crop and caused Pb phytostabilization and thereby, suppressed its entry in the above-ground plant parts.

 抽象的

植物-微生物相互作用是解决土壤重金属问题的重要工具。进行盆栽试验以评估耐铅根际细菌在铅胁迫下改善豌豆生长的效率。硫酸铅(PbSO ₄ )用于加标(250、500和750 mg kg ^-1 )。结果表明，接种耐铅PGPR菌株不仅减轻了Pb对植物生长的有害影响，而且将其固定在土壤中。与未接种的对照相比，在浓度为0、250、500和750 mg kg ^-1的Pb存在下，PGPR使芽和根长度分别增加21、15、18%和72、80、84%。此外，当Pb浓度为250、500和750 mg kg ^-1时，地上部和根的新鲜生物量也分别增加了51、45、35%和57、101、139%。此外，与未接种对照相比，接种PGPR还使根和地上部的Pb浓度分别降低了57%、55%、49%和70%、56%和58%。因此，PGPR 被证明是降低 Pb 迁移率的有效选择，并可有效用于其植物稳定化。

 新颖性声明

铅（Pb）是一种剧毒元素，是自然界中第二大有毒元素，具有很高的持久性。它在优先危险物质清单中排名^第一，进入生命系统后会产生不良影响。因此，对其进行修复是不可避免的。植物根际促生长细菌（PGPR）不仅具有在胁迫环境下生存的潜力，而且由于其不同的植物生长促进机制而促进植物生长。

大多数研究人员都致力于研究其在植物体内的生物累积性。然而，这项研究使用豌豆作为试验作物，导致铅植物稳定化，从而抑制其进入地上植物部分。