Plant Growth-Promoting Rhizobacteria (PGPR): A Rampart against the Adverse Effects of Drought Stress
Naoual Bouremani,
Hafsa Cherif-Silini,
Allaoua Silini,
Ali Chenari Bouket,
Lenka Luptakova,
Faizah N. Alenezi,
Oleg Baranov,
Lassaad Belbahri
Affiliations
Naoual Bouremani
Laboratory of Applied Microbiology, Department of Microbiology, Faculty of Natural and Life Sciences, University Ferhat Abbas of Setif, Setif 19000, Algeria
Hafsa Cherif-Silini
Laboratory of Applied Microbiology, Department of Microbiology, Faculty of Natural and Life Sciences, University Ferhat Abbas of Setif, Setif 19000, Algeria
Allaoua Silini
Laboratory of Applied Microbiology, Department of Microbiology, Faculty of Natural and Life Sciences, University Ferhat Abbas of Setif, Setif 19000, Algeria
Ali Chenari Bouket
East Azarbaijan Agricultural and Natural Resources Research and Education Centre, Plant Protection Research Department, Agricultural Research, Education and Extension Organization (AREEO), Tabriz 5355179854, Iran
Lenka Luptakova
Department of Biology and Genetics, University of Veterinary Medicine and Pharmacy in Košice, 04181 Kosice, Slovakia
Faizah N. Alenezi
Marine Biodiscovery Centre, Department of Chemistry, University of Aberdeen, Old Aberdeen, Aberdeen AB24 3UE, UK
Oleg Baranov
Department of Biological Sciences, National Academy of Sciences of Belarus, 220072 Minsk, Belarus
Lassaad Belbahri
Laboratory of Soil Biology, University of Neuchatel, 11 Rue Emile Argand, CH-2000 Neuchatel, Switzerland
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.
