Bacteria in Soil: Promising Bioremediation Agents in Arid and Semi-Arid Environments for Cereal Growth Enhancement

Abstract

In arid regions, starchy agricultural products such as wheat and rice provide essential carbohydrates, minerals, fibers and vitamins. However, drought, desiccation, high salinity, potentially toxic metals and hydrocarbon accumulation are among the most notable stresses affecting soil quality and cereal production in arid environments. Certain soil bacteria, referred to as Plant Growth-Promoting Rhizobacteria (PGPR), colonize the plant root environment, providing beneficial advantages for both soil and plants. Beyond their ability to improve plant growth under non-stressed conditions, PGPR can establish symbiotic and non-symbiotic interactions with plants growing under stress conditions, participating in soil bioremediation, stress alleviation and plant growth restoration. Moreover, the PGPR ability to fix nitrogen, to solubilize insoluble forms of nutrients and to produce other metabolites such as siderophores, phytohormones, antibiotics and hydrolytic enzymes makes them ecofriendly alternatives to the excessive use of unsuitable and cost-effective chemicals in agriculture. The most remarkable PGPR belong to the genera Arthrobacter, Azospirillum, Azotobacter, Bacillus, Enterobacter, Klebsiella, Pseudomonas, etc. Therefore, high cereal production in arid environments can be ensured using PGPR. Herein, the potential role of such bacteria in promoting wheat and rice production under both normal and derelict soils is reviewed and highlighted.