Salt stress mitigation in Lathyrus cicera by combining different microbial inocula

Area of Science:

• Agricultural Science
• Plant Science
• Microbiology

Background:

• Arid and semi-arid regions face environmental challenges exacerbated by climate change.
• Salinity is a major abiotic stress limiting crop yield and soil fertility.
• Limited information exists on salinity's impact on Lathyrus cicera development and nitrogen fixation.

Purpose of the Study:

• To evaluate the efficacy of various microbial inocula in mitigating salinity stress in Lathyrus cicera.
• To assess the impact of nitrogen-fixing Rhizobium, arbuscular mycorrhizal fungi (AMF), and plant growth-promoting bacteria (PGPB) on salt-stressed legume plants.
• To investigate the combined effects of PGPB and AMF on Lathyrus cicera under saline conditions.

Main Methods:

• A pot trial was conducted using Lathyrus cicera plants subjected to 100 mM NaCl salinity.
• Inoculation treatments included Rhizobium laguerreae, Rhizophagus irregularis (AMF), a native AMF consortium, and various PGPB (Bacillus species).
• Plant growth, biochemical traits, and the expression of salinity tolerance genes (LcHKT1, LcNHX7) were analyzed.

Main Results:

• Salinity significantly reduced Lathyrus cicera plant growth and development.
• All microbial inoculations enhanced plant growth and improved biochemical parameters under salt stress.
• Combined inoculation with PGPB and AMF demonstrated the most significant mitigation of salinity's adverse effects.
• Co-inoculation upregulated the expression of LcHKT1 and LcNHX7 genes, indicating enhanced salinity tolerance.

Conclusions:

• Microbial inoculants, particularly the combination of AMF and PGPB, are effective in alleviating salinity stress in Lathyrus cicera.
• This AMF/PGPB formulation shows potential as a biofertilizer for improving crop productivity in saline environments.
• The study highlights the role of beneficial microbes in enhancing plant resilience to abiotic stresses like salinity.