Halo-tolerant plant growth promoting rhizobacteria for improving productivity and remediation of saline soils

Naveen Kumar Arora; Tahmish Fatima; Jitendra Mishra; Isha Mishra; Sushma Verma; Renu Verma; Maya Verma; Ankita Bhattacharya; Priyanka Verma; Priya Mishra; Chanda Bharti

doi:10.1016/j.jare.2020.07.003

Halo-tolerant plant growth promoting rhizobacteria for improving productivity and remediation of saline soils

J Adv Res. 2020 Jul 11:26:69-82. doi: 10.1016/j.jare.2020.07.003. eCollection 2020 Nov.

Authors

Affiliations

¹ Department of Environmental Science, School for Environmental Sciences, Babasaheb Bhimrao Ambedkar University, Lucknow, UP, India.
² Department of Microbiology, Babasaheb Bhimrao Ambedkar University, Lucknow, UP, India.
³ DST-CPR, Babasaheb Bhimrao Ambedkar University, Lucknow, UP, India.
⁴ Uttar Pradesh Pollution Control Board (UPPCB), Lucknow, UP, India.

Abstract

Background: The collective impact of climate change and soil salinity is continuously increasing the degraded lands across the globe, bringing agricultural productivity and food security under stress. The high concentration of salts in saline soils impose osmotic, ionic, oxidative and water stress in plants. Biological solutions can be the most reliable and sustainable approach to ensure food security and limit the use of agro-chemicals.

Aim of review: Halo-tolerant plant growth promoting rhizobacteria (HT-PGPR) are emerging as efficient biological tools to mitigate the toxic effects of high salt concentrations and improve the growth of plants, simultaneously remediating the degraded saline soils. The review explains the role of HT-PGPR in mitigating the salinity stress in plants through diverse mechanisms and concurrently leading to improvement of soil quality.

Key scientific concepts of review: HT-PGPR are involved in alleviating the salinity stress in plants through a number of mechanisms evoking multipronged physiological, biochemical and molecular responses. These include changes in expression of defense-related proteins, exopolysaccharides synthesis, activation of antioxidant machinery, accumulation of osmolytes, maintaining the Na⁺ kinetics and improving the levels of phytohormones and nutrient uptake in plants. The modification of signaling by HT-PGPR inoculation under stress conditions elicits induced systemic resistance in plants which further prepares them against salinity stress. The role of microbial-mechanisms in remediating the saline soil through structural and compositional improvements is also important. Development of novel bioinoculants for saline soils based on the concepts presented in the review can be a sustainable approach in improving productivity of affected agro-ecosystems and simultaneously remediating them.

Keywords: Exopolysaccharides; Plant growth promoting rhizobacteria; Remediation; Salinity; Sustainable agriculture.

Publication types

Review