Ethylene–potassium interactions safeguard ionic balance, chlorophyll biosynthesis, and source–sink metabolism to sustain wheat growth and yield responses under salt stress

• Salt stress inhibits ionic-homeostasis, source-sink metabolism and yield. • Application of K + and ethylene mitigated the adverse impacts of salt stress. • K + and ethylene supplementation activated antioxidant defense system to reduce ROS. • Optimum K + and ethylene application overturned the negative impacts of salt stress. Significant reduction in crop yields has been caused due to salt-impacted soils. In order to meet hunger requirements, significant solutions are required for speeding up agricultural production even in salt-impacted soils. As salt stress reduces the uptake of potassium (K + ), replenishing the K + nutrition may serve as a tolerance mechanism. Therefore, the present study investigated the different K + levels (low, optimum, and excess) along with a stress hormone, ethylene in modulating plant responses under salt stress. The present results demonstrated that the interplay of ethylene and K + significantly altered salt induced inhibition through improved K + retention, chlorophyll biosynthesis, and source-sink metabolism to protect growth and yield traits. Additionally, ethylene and K + improved key pathways such as defense machinery, nitric oxide (NO) biosynthesis along with secondary metabolites (lignin, cellulose, flavonoid and phenol) to overcome salt-induced adversities. The impacts posed by the interplay between ethylene and different K + levels depicted a variable mitigation of salt induced adversities. Conclusively, ethylene and optimum K + treatment best excruciated the salt-inhibited responses. Supplementation of norbonadiene (NBD, ethylene action inhibitor) further confirmed the role of interplay between ethylene and differential K + concentrations in mediating the salt stress responses. The present study pose as a significant strategy towards cultivar development programs to counter salt-inhibited constraints and paves way to ensure crop security.