Strategies of Rhizospheric Microbes in Heavy Metal Management and Remediation

Abstract

Extensive industrialization has led to a prominent increase in the levels of numerous heavy metals (HMs) in both terrestrial and aquatic environment. These HMs have caused widespread damage to agriculture through extreme crop production loss and decreased food quality. Most major crops are now facing a serious threat due to these HMs as seeds, fruits, and other edible parts are now showing high traces of these HMs. At the same time, these HMs decrease soil nutrient concentration, lower plant growth, and accumulate in roots and shoots, etc. To deal with the HMs’ stress, rhizospheric microbes have been found to play a profound role and maintain soil health. Endophytes constitute the largest group of microbes that are found associated internally within the plant tissues and have symbiotic associations with their host plant tissues. These endophytes have gained considerable attention in ameliorating plant stress in recent decades and offer a bio-based sustainable strategy for removing heavy metal contamination from soil. One of the prominent examples of rhizospheric microbe is plant growth-promoting rhizobacteria (PGPRs) that stimulate plant growth and development in the presence of HMs in soil. Another class of important rhizospheric microbes are arbuscular mycorrhizal fungi or AM fungi that notably provides plant protection from the negative effects of different abiotic stress, including HMs. AMF is known to augment P-uptake from soil and secrete the number of low molecular weight protein that help in HM sequesteration. The present chapter will highlight the significant application of these rhizospheric microorganisms in HM tolerance and mitigation in different plants. Additionally, the chapter also provide a discussion on different mechanisms by which these rhizospheric microorganisms help in HM detoxification and improve plant growth and development. © 2025 selection and editorial matter, Piyush Mathur and Soumya Mukherjee; individual chapters, the contributors.