Plant Growth-Promoting Rhizobacteria (PGPR): A Rampart against the Adverse Effects of Drought Stress

Abstract

Abiotic stress significantly limits plant growth and production. Drought, in particular, is a severe constraint that affects growth and limits agricultural productivity on a global scale. Water stress induces in plants a set of morpho-anatomical (modification of root and leaf structure), physiological, and biochemical (relative water content, membrane stability, photosynthesis, hormonal balance, antioxidant systems, and osmolyte accumulation) changes mainly employed to cope with the drought stress. These strategies allow the plant to overcome the unfavorable period of limited water availability. Currently, a promising alternative is available to improve plant growth and tolerance under drought conditions. The use of osmotolerant plant growth-promoting rhizobacteria (PGPR) as inoculants can alleviate water stress by increasing the water use efficiency of the plant. The PGPR improve the tolerance of plants to drought, through changes in the morphology and architecture of the root system, production of phytohormones, extracellular polysaccharides, ACC 1-(aminocyclopropane-1-carboxylate) deaminase, volatile chemicals, and osmolyte accumulation. They may also enhance the antioxidant defense system and induce transcriptional regulation of stress response genes. This review addresses the effects of stress on plant growth, adaptation, and response to drought conditions and discusses the significant potential of PGPR to modulate the physiological response against water scarcity, ensuring plant survival and improving the resistance and growth of agricultural crops.

Snap Bean Plants' Physio-Biochemical Reactions to Plant Growth-Promoting Rhizobacteria to Mitigate the Negative Effects of Drought Stress

“…Plant growth-promoting rhizobacteria (PGPR) are the rhizospheric bacteria that in uence positively plant growth and provide stress resistance by altering root morphology/architecture which promote water absorption and transport (Bouremani et al 2023), favouring the absorption of nutrients via nitrogen xation, phosphorus solubilizing and uptake of other micro and macronutrients such as potassium,…”

“…Such results are in harmony with(Silva et al 2019). This simulative effect could be attributed to the EPSs produced by PGPR which are crucial for protecting and maintaining the membrane structure under drought stress(Bouremani et al 2023). Furthermore, the increased integrity of cell membranes caused by PGPR inoculation may be a result of PGPR activating the antioxidant defense system, increasing drought tolerance(Mansour et al 2021).It is well documented that drought stress boosts the overproduction of ROS in plant cells, inducing oxidative stress(Armada et al 2014), and to counteract ROS overproduction, plants accumulate several protective osmolytes, proteins, non-enzymatic metabolites, and antioxidant enzymes that can scavenge ROS under water stress(Hosseini et al 2018).…”

Ability of nitrogen-fixing bacteria to alleviate drought stress in cowpea varies depending on the origin of the inoculated strain

“…Drought is a major stress factor that signi cantly hampers plant growth and reduces crop yield. The intensi cation of climate change has resulted in more frequent water restrictions, causing a signi cant drop in food production (Chaudhry and Sidhu 2022;Bouremani et al 2023). In the present study, we investigated the potential of rhizobacteria, speci cally Microvirga vignae (strains BR 3296 and BR 3299) and Bradyrhizobium sp.…”

“…Crop yields are consistently in uenced by environmental conditions, with drought being a severe constraint that hinders growth and limits agricultural productivity worldwide (Bouremani et al 2023). More than 50% of the Earth's surface is arid, semiarid, or subjected to drought stress (Arzanesh et al 2011).…”

Sustainable Rehabilitation of Post-Bauxite Mining Land for Albizia falcata Cultivation Using Specific Location Amelioration Technology

“…The decrease in available phosphorus in other treatments may be due to an increase in soil pH, which enhances the solubility of base cations, particularly calcium (Ca) ions. This can result in the binding of phosphate ions to calcium ions, leading to reduced phosphorus availability [52,53]. Additionally, high levels of organic matter from cow manure can promote phosphorus fixation and reduce its availability [54].…”