Lead-Tolerant Bacteria Can Minimize Lead Toxicity in Plants

Abstract

In today’s world, environment is exposed to lead due to various anthropogenic activities. It adversely affects plants as well as microorganisms by disturbing soil health and fertility. Bioremediation is a technique used to sequester heavy metals from the contaminated soil and it can be used to decontaminate the polluted soil. Lead-tolerant plant health promoting rhizobacteria (PHPR) can be used to enhance the efficacy of lead remediation. Lead uptake can be enhanced through bacteria by modifying root structure, secreting metal sequestering molecules in rhizosphere and alleviating lead induced phytotoxicity. For this purpose, lead-resistant auxin-producing bacteria were isolated from the rhizosphere of some plants. These auxin-producing lead-tolerant bacteria were used to treat Zea mays both in the presence and absence of lead-stress under laboratory conditions and its impact on plant growth and biochemical parameters of Zea mays were analysed.

Interactive Biology of Auxins and Phenolics in Plant Environment

“…They may have the influence over soil microbiota which are present in the vicinity of plant roots, together with hormonal balance, nutrient competition with neighboring plants, and various enzymatic activities (Hattenschwiler and Vitousek 2000;Kraus et al 2003). Some microbes, present in plant rhizosphere, have the potential to produce auxins, an important plant growth regulator which when taken up by plants ultimately enhances plant growth, thus known as auxin-producing rhizobacteria (Ahmed and Hasnain 2010;Aslam and Ahmed 2018;Karamat and Ahmed 2018; Arabidopsis plant when exposed to biotic (pathogenic attack) and abiotic stress (pH, temperature, salinity, and heavy metal stress) initiates various metabolic processes through shikimate pathway, synthesizing different aromatic amino acids that act as precursors, i.e., phenylalanine/L-tyrosine and L-tryptophan which both are formed through chorismate, end product of shikimate pathway, for the synthesis of different compounds including auxins and phenolic compounds, respectively Habib et al 2019). Moreover, phenolics present in rhizosphere bind with organic matter and are metabolized by rhizobacteria.…”