PGPR's mix treatment to Moringa improved plant growth and iron content in foliage as substantiated by biochemical and molecular methods

In this study, Bacillus pumilus SE34 and B. pumilus T4 were combined with Bacillus subtilis GBO3, B. pumilus INR7 and Pseudomonas fluorescens UOM14 to form COM1, COM2 and COM3, respectively. All combinations were used to find their synergistic effect on Moringa oleifera for growth promotion and Fe accumulation efficiency in foliage. The results indicate a significant increase in Fe content in foliage using COM3 (405.70%) followed by COM2 (105.83%) in comparison to the control with a simultaneous decrease in the soil Fe content. Increased expression of iron-transport-related genes like iron-phytosiderophore oligopeptide transporter and natural-resistance-associated macrophage protein, in foliage of Moringa using real-time PCR correlates with the enriched iron content in foliage of treated plants. Increase in citric acid was in direct relation to the Fe accumulation in foliage. Growth promotion and Fe enhancement using plant-growth-promoting rhizobacteria's combination was significantly higher, proving its synergistic effect as a great source for sustainable development in agriculture and nutrition.