Mangrove derived coactive bacterial inoculant triggered biochemical traits rejuvenating plant cell function under salt stress

Crop yield is being impacted by global warming, which threatens food security. Salinization of soil or irrigation water is becoming increasingly prevalent in most agricultural terrain, especially around the coast. In India, it is estimated that approximately 10% of additional area is getting salinized, and around 50% of the arable land would be salt-affected by the year 2050. Finding innovative techniques that enable farmers to sustain production in an increasingly saline environment is crucial given the world's population expansion and the depletion of natural resources used in agriculture. Biostimulants are naturally occurring compounds or microorganisms that are used to promote plant functions such as nutrient absorption, nutrient utilisation efficiency, abiotic stress tolerance and the overall quality of the resulting agricultural products. In the present work, we evaluated the agronomic effectiveness of a novel formulated biostimulant consisting of four strains of endophytic bacteria isolated from the roots of mangrove plants of Sundarbans in a crop of great interest (Tomato) under control conditions and salt stress. Our research has shown that our product had a positive effect on the biochemical parameters in tomato plants under salt stress. The application of our biostimulant also increased osmolyte production and maintained Na ⁺ /K ⁺ homeostasis under salt conditions. Similarly, when exposed to salinity, the biostimulant increased the concentration of signature molecules including primary metabolites, phenolic compounds, polyamines and phytohormones inside the plant cell. This study enriched our body of knowledge by providing novel perspectives on the mechanism of salt resistance that endophytic microbes provide through symbiosis.