Iron deficiency in crops significantly reduces yield, impacting agricultural productivity worldwide. To address this issue, synthetic Fe chelates are commonly applied, but their prolonged use poses environmental risks. Thus, inoculation of plant growth-promoting bacteria (PGPB) rises as an alternative to enhance iron uptake in crops while minimizing reliance on synthetic chelates. This study aimed to examine the influence of Pseudomonas RMC4 inoculation and pyoverdine application on cucumber plants cultivated hydroponically under Fe deficiency conditions. Evaluations included the SPAD index, plant biomass, root morphology, Fe-chelate reductase activity, gene expression, and ionomic analysis. Following Fe deficiency, Pseudomonas RMC4 inoculation improved the SPAD index, increased dry weight, enhanced root development, and facilitated Fe acquisition mechanisms. This improvement was observed with bacterial inoculation or pyoverdine application alongside an insoluble Fe source (ferrihydrite). Overall, the results suggest the beneficial impact of Pseudomonas RMC4 inoculation in alleviating symptoms of Fe deficiency. Future studies will investigate bacterial application under field conditions to assess its potential in reducing the need for synthetic Fe chelates in crop production.
In the present work, the efficiency of Pseudomonas RMC4 to mitigate Fe-deficiency symptoms of cucumber plants under hydroponic conditions was evaluated. The following determinations were performed: SPAD index, plant biomass, root morphology, ferric-chelate reductase activity, gene expression, and ionomic analysis. The results suggest that Pseudomonas RMC4 could help cucumber plants to reduce Fe-deficiency symptoms through plant development and improve the plant´s inherent mechanisms for Fe uptake, although, Pseudomonas RMC4 does not completely solve the Fe defficiency problem.
