Halotolerant plant growth-promoting rhizobacteria from rice and wheat in sodic soils: Characterization for their potential to alleviate salt stress

Microbial Interventions for Sustainable Agriculture: Plant GrowthPromoting Rhizobacteria (PGPR) Activity of Isolates of Saline Soils from Karad Taluka, Maharashtra, India

Soil salinity remains a major abiotic factor limiting agricultural productivity worldwide, with the situation worsening in parts of Maharashtra, particularly Karad Taluka. This study examined saline soils from various locations within Karad, assessing their physicochemical properties and isolating indigenous halotolerant bacterial strains that exhibit plant growthpromoting rhizobacterial (PGPR) traits. The soil analysis revealed highly alkaline pH levels (8.8-9.4), elevated sodium concentrations, and deficiencies in organic carbon, nitrogen, and micronutrients. Five halotolerant bacterial isolates (Ko1, Va1, Be1, Vm1, and At1) were obtained and evaluated for PGPR activities such as phosphate and potassium solubilization, nitrogen fixation, indole-3-acetic acid (IAA) production, and siderophore synthesis. All isolates demonstrated positive results in phosphate and potassium solubilization, nitrogen fixation, and IAA production, with four also producing siderophores. Notably, isolates Be1, Vm1, and At1 showed strong performance across multiple traits, highlighting their potential as bioinoculant candidates. These findings suggest that native halotolerant PGPR strains from Karad Taluka could enhance soil fertility, improve nutrient uptake, and support plant growth in saline conditions. Future research including field trials and molecular characterization could facilitate the development of environmentally sustainable microbial formulations for saline agriculture.

Unveiling the plant growth-promoting and bioremediation potential of bacteria isolated from onion rhizosphere soils irrigated with industrial wastewater

Novel halotolerant fungal endophytes from hypersaline coastal ecosystems as sustainable biostimulants for early growth performance of tomato and wheat under saline stress

This study provides the first evidence of S. fimicola, Clarireedia narcissi, and N. gossypiicola as effective fungal biostimulants under saline stress and highlights the biotechnological potential of non-conventional endophytes from extreme coastal environments as a basis for the rational selection of sustainable bioinoculants for salt-affected agricultural systems.

Responses of growth and quality of Glycyrrhiza uralensis to salt-alkali-tolerant microbial inoculant via the remodeling of rhizosphere microenvironments in moderate and severe saline-alkali soils

The combined application of microbial inoculation and seedling transplanting is recommended for large-scale and high-quality cultivation of G. uralensis in moderately saline-alkali soils of arid northwestern China, as this integrated practice maximizes plant growth, medicinal compound accumulation, and rhizosphere microenvironment optimization.

Interannual Covariation of Rhizosphere Microbiomes and Plant Performance in Coastal Saline–Alkali Soils Ameliorated by Nitraria tangutorum

Soil salinization severely threatens agricultural productivity and ecosystem sustainability, particularly in coastal regions. Halophyte-based phytoremediation is a promising strategy, yet how rhizosphere soil legacy effects at different restoration ages influence subsequent plant growth and microbial communities remains poorly understood. Here, rhizosphere soils of Nitraria tangutorum at 1- (BC-1), 2- (BC-2), and 3-year (BC-3) restoration stages and non-rhizosphere bulk soil (CK) were sampled, with alfalfa cultivated as a bioindicator to assess soil physicochemical properties, plant growth, stress physiology, and rhizosphere microbiota. With increasing restoration age, rhizosphere soil shifted from a state of salt accumulation and nutrient deficiency to one of salt depletion and nutrient enrichment, with BC-3 exhibiting the highest soil organic matter, total phosphorus, and alkali-hydrolyzable nitrogen and the lowest total salt and soluble Na+. Alfalfa growth was suppressed in BC-1 and BC-2 soils, but significantly promoted in BC-3, accompanied by the lowest malondialdehyde and proline content, indicating effective alleviation of oxidative and osmotic stress. Microbial diversity peaked at BC-2, whereas the total proportion of halotolerant bacteria declined from 0.44 (BC-1) to 0.34 in BC-3 (significantly lower than CK), suggesting a successional shift from a stress-dominated community toward a functionally specialized consortium. Regression analyses identified soluble sodium as the variable most strongly associated with growth inhibition (R2 > 0.80) for plant height and root length. We suggest soluble sodium may represent the principal factor associated with growth inhibition and that a positive-feedback loop among plant Na+ sequestration, microbial carbon sequestration, and soil maturation may sustain long-term saline–alkali soil improvement. These findings suggest a three-stage successional mechanism and highlight the critical role of restoration age in mediating plant–microbe–soil synergistic remediation of coastal saline soils.

Combined microbial inoculation improves plant growth, nutrient acquisition, and soil biological functioning in Opuntia ficus-indica under water deficit