The role of plant growth promoting rhizobacteria in plant drought stress responses

Abstract

Climate change has exacerbated the effects of abiotic stresses on plant growth and productivity. Drought is one of the most important abiotic stress factors that interfere with plant growth and development. Plant selection and breeding as well as genetic engineering methods used to improve crop drought tolerance are expensive and time consuming. Plants use a myriad of adaptative mechanisms to cope with the adverse effects of drought stress including the association with beneficial microorganisms such as plant growth promoting rhizobacteria (PGPR). Inoculation of plant roots with different PGPR species has been shown to promote drought tolerance through a variety of interconnected physiological, biochemical, molecular, nutritional, metabolic, and cellular processes, which include enhanced plant growth, root elongation, phytohormone production or inhibition, and production of volatile organic compounds. Therefore, plant colonization by PGPR is an eco-friendly agricultural method to improve plant growth and productivity. Notably, the processes regulated and enhanced by PGPR can promote plant growth as well as enhance drought tolerance. This review addresses the current knowledge on how drought stress affects plant growth and development and describes how PGPR can trigger plant drought stress responses at the physiological, morphological, and molecular levels.

Optimizing chili production in drought stress: combining Zn-quantum dot biochar and proline for improved growth and yield

“…Drought-induced stress is a prominent abiotic factor impacting crops, initiating biochemical alterations. It significantly hinder plant growth, delay development, and decrease productivity 37 . The roots actively seek to absorb increased amounts of water as they expand, thereby enabling plants to adjust and reduce water loss through stomatal closure during periods of water scarcity 38 .…”

Mitigating drought stress in wheat plants (Triticum Aestivum L.) through grain priming in aqueous extract of spirulina platensis

“…The decrease in wheat yield due to water stress can be linked to drought’s inhibitory impact on plant growth, stemming from the suppression of various metabolic processes. Additionally, drought conditions necessitate high energy and carbohydrate expenditure for osmoregulation and disrupt normal cell functions, further contributing to the reduction in photosynthesis and overall yield [ 121 ].…”

Synergistic interactions of nanoparticles and plant growth promoting rhizobacteria enhancing soil-plant systems: a multigenerational perspective

“…While single use of PGPR has never been shown to improve soil WHC and water content, it can increase water-deficit resistance capacity to crop plants. However, enhanced WHC by the application of NPs, synergize with PGPR given that the nutrient cycling, breakdown of soil organic matter, and microbial signaling considering higher soil moisture levels [ Figure 2 ] ( Verma et al., 2020b ; Ahmad et al., 2022 ; Chieb and Gachomo, 2023 ). It should be highlighted that the indirect significance of NPs with PGPR application has yet to be conducted.…”

“…Many researchers have demonstrated their effectiveness in combating drought, soil flooding, salinity, low and high light intensities, nutritional imbalance, and heavy metal contamination. Plants can develop stress tolerance efficiency by exploiting the ability of PGPR to release exopolysaccharides in dry environments ( Vurukonda et al., 2016 ; Ahmad et al., 2022 ; Chieb and Gachomo, 2023 ). In saline environments, it increases water absorption, decreases stomatal conductance, boosts potassium accumulation at the cost of sodium, reduces the direct negative impacts of soil salinity, and increases antioxidant enzyme activities.…”