Microbial Dream Team Boosts Cotton’s Survival in Salty Soils

A groundbreaking study published in Current Microbiology demonstrates how a pair of salt-tolerant Plant Growth-Promoting Rhizobacteria (PGPR)—Pseudomonas hunanensis RT-12 and Staphylococcus caprae DS-2—work together to dramatically improve cotton growth under severe salinity.

Soil salinity is a rising global threat, already affecting 20% of cultivated land and projected to threaten half of all arable land by 2050. Salt stress impairs plant water uptake, disrupts ion balance, and triggers oxidative damage, ultimately stunting growth and decreasing productivity.

A Synergistic Duo from the Cotton Rhizosphere

The researchers isolated 32 rhizobacterial strains from the cotton rhizosphere and selected two top performers based on halotolerance and multiple beneficial traits. Both RT-12 and DS-2 produced IAA, solubilized phosphate, secreted siderophores, and showed strong enzyme activity. RT-12 also produced hydrogen cyanide, hinting at potential biocontrol properties.

Pot Experiments Under 200 mM Salt Stress

Under controlled 200 mM NaCl conditions, the study compared untreated cotton plants with single-strain and dual-strain inoculations. The results were striking:

Shoot and root length increased significantly
Chlorophyll a, chlorophyll b, and carotenoids were restored
Oxidative stress markers (MDA and H₂O₂) dropped sharply
Antioxidant enzymes SOD and POD increased the most in the dual treatment
Proline accumulation—key to osmotic balance—was highest in co-inoculated plants

The dual inoculation consistently outperformed single-strain treatments, revealing a strong synergistic effect.

Enhanced Ionic Balance and Redox Regulation

The consortium improved osmotic adjustment, ionic homeostasis, and redox balance—helping cotton maintain growth despite high sodium levels. PCA and clustering analyses further confirmed that PGPR-treated plants grouped distinctly from stressed, untreated plants due to improved growth and biochemical traits.

Sustainable Solution for Salt-Affected Agriculture

The findings highlight the promise of integrating native microbial consortia into sustainable cotton production in salt-affected regions. Unlike chemical inputs, PGPR-based solutions offer eco-friendly, biologically driven stress mitigation.

The authors emphasize the need for field-scale evaluations and commercial formulation development to bring this “microbial dream team” to farmers battling soil salinity.

Reference

Ullah, A., Ahmad, S., Azeem, M.A. et al. Microbial Dream Team: Cotton Performs Better in Salty Soil with Pseudomonas hunanensis RT-12 and Staphylococcus caprae DS-2. Curr Microbiol 83, 31 (2026). https://doi.org/10.1007/s00284-025-04614-2