Scholarlink

Background <p>Lead (Pb) pollution is a major environmental problem stemming from increasing industrial and human activity, significantly influencing soil quality and plant productivity. This study aimed to identify and characterise lead-tolerant rhizobacteria from polluted agricultural soil and assess their potential bioremediation ability and impact on plant growth under Pb stress.</p> Results <p>Fifteen lead-tolerant bacterial (LTB) strains exhibited maximum tolerance capacity (MTC) and biosorption efficiency. After removing 89.46% and 50.62% Pb from 5 to 10 mM Pb(NO<sub>3</sub>)<sub>2</sub>, respectively, LTB-13 and LTB-7 showed maximum Pb tolerance (up to 15 mM) and biosorption capacities. These LTBs produced IAA, GA₃, ammonia, HCN, siderophores, solubilized phosphate, potassium, zinc, silica, etc. In vitro pot investigations on maize (<i>Zea mays</i> L.) exposed to 10 mM and 15 mM Pb stress showed substantial increases in root and shoot biomass, chlorophyll content, and antioxidant enzyme activities (SOD, CAT, POD, PPO, PAL). PCA accounted for 85.09% of total variance via PC1 (71.43%) and PC2 (13.66%), separating growth-related traits from stress responses. Treatments were divided into two core groups using PCA-K-means clustering. Agglomerative hierarchical clustering verified treatment consistency and unique responses and identified promising groups for further exploration and optimization. Furthermore, LTB inoculation significantly reduced Pb accumulation in plant tissues. By 16&#xa0;S rRNA gene sequencing, LTB-13 and LTB-7 were identified as <i>Klebsiella variicola</i> and <i>Bacillus tequilensis</i>.</p> Conclusion <p>The study provides a significant step forward in sustainable soil remediation by demonstrating the dual roles of <i>Klebsiella variicola</i> and <i>Bacillus tequilensis</i> in lead detoxification and plant growth promotion under Pb stress. These rhizobacteria demonstrated strong lead biosorption capacity and significantly enhanced maize physiological and antioxidant responses, while also lowering Pb buildup in plant tissues. Importantly, the work not only adds to better soil and crop health, but it also correlates with key UN Sustainable Development Goals (SDGs 2, 3, 6, 12, and 15), offering a feasible and scalable microbial strategy for combating heavy metal pollution in agriculture.</p>

错误：搜索内容不能为空，请输入英文关键词
错误：关键词超出字数限制，请精简
高级检索

Role of newly isolated plant growth-promoting lead-tolerant bacteria in lead bio-remediation and plant growth performance under lead stress

  • 期刊论文

  • 出版模式：

    开放获取

  • 发表日期：

    2025年10月1日

查看全文
  • Simran Yadav,
  • Rajnish Kajala,
  • Deepak Rajpurohit,
  • Sudhir Kumar Upadhyay,
  • Prasann Kumar,
  • Abhijeet Singh,
  • Devendra Jain

摘要

Background

Lead (Pb) pollution is a major environmental problem stemming from increasing industrial and human activity, significantly influencing soil quality and plant productivity. This study aimed to identify and characterise lead-tolerant rhizobacteria from polluted agricultural soil and assess their potential bioremediation ability and impact on plant growth under Pb stress.

Results

Fifteen lead-tolerant bacterial (LTB) strains exhibited maximum tolerance capacity (MTC) and biosorption efficiency. After removing 89.46% and 50.62% Pb from 5 to 10 mM Pb(NO3)2, respectively, LTB-13 and LTB-7 showed maximum Pb tolerance (up to 15 mM) and biosorption capacities. These LTBs produced IAA, GA₃, ammonia, HCN, siderophores, solubilized phosphate, potassium, zinc, silica, etc. In vitro pot investigations on maize (Zea mays L.) exposed to 10 mM and 15 mM Pb stress showed substantial increases in root and shoot biomass, chlorophyll content, and antioxidant enzyme activities (SOD, CAT, POD, PPO, PAL). PCA accounted for 85.09% of total variance via PC1 (71.43%) and PC2 (13.66%), separating growth-related traits from stress responses. Treatments were divided into two core groups using PCA-K-means clustering. Agglomerative hierarchical clustering verified treatment consistency and unique responses and identified promising groups for further exploration and optimization. Furthermore, LTB inoculation significantly reduced Pb accumulation in plant tissues. By 16 S rRNA gene sequencing, LTB-13 and LTB-7 were identified as Klebsiella variicola and Bacillus tequilensis.

Conclusion

The study provides a significant step forward in sustainable soil remediation by demonstrating the dual roles of Klebsiella variicola and Bacillus tequilensis in lead detoxification and plant growth promotion under Pb stress. These rhizobacteria demonstrated strong lead biosorption capacity and significantly enhanced maize physiological and antioxidant responses, while also lowering Pb buildup in plant tissues. Importantly, the work not only adds to better soil and crop health, but it also correlates with key UN Sustainable Development Goals (SDGs 2, 3, 6, 12, and 15), offering a feasible and scalable microbial strategy for combating heavy metal pollution in agriculture.