Cyanobacteria inoculation mitigates salinity stress by regulating plant growth, photosynthetic performance, elemental concentrations and yield in wheat

Salinity stress is a significant global threat to agricultural productivity, particularly affecting crop yields in arid and semi-arid regions. Cyanobacteria (BGA) offer an environmentally friendly solution for the recovery of salt-affected soils. This study investigated the potential of BGA inoculation to mitigate salinity stress in wheat. Four BGA strains (Jaaginema pseudogeminatum, Lyngbya austeri, Nostoc hatei, and Phormidium tenue) were evaluated for their effects on wheat growth, physiological performance, and yield under saline conditions (0, 4, 8, and 12 dS m^-1 NaCl). The objective was to assess the ability of BGA to enhance wheat resilience to salinity through improved nutrient uptake, photosynthetic efficiency, and water use efficiency (WUE). The results indicate that salinity stress significantly reduced wheat growth and yield, but BGA inoculation alleviated these adverse effects. P. tenue increased the net photosynthetic rate by 210 %, WUE by 185 %, and total phenol content by 101 %, at 12 dS m^-1 salinity. Additionally, BGA inoculation reduced Na accumulation in plants while enhancing N, K, and Ca uptake. Morphological characteristics of wheat, such as plant dry weight, number of fertile spikelets, and 1000-seed weight, were also improved with BGA application. Among the strains, P. tenue was the most effective in mitigating the negative effects of salinity on wheat. The findings demonstrate that BGA inoculation can enhance wheat's tolerance to salinity by improving nutrient availability, photosynthetic performance, and osmotic adjustment. This eco-friendly approach offers a sustainable solution for reclaiming salt-affected soils and improving crop productivity in saline environments. Further field studies are recommended to validate these results under diverse environmental conditions and to explore the broader application of BGA in sustainable agriculture.