Tracking GFP-Marked Osmoprotectant Rhizobacteria in the Rhizosphere of Mung Bean under Sterile Conditions of 60% FC

This study aims to investigate osmoprotectant rhizobacteria producing glycine betaine, marked with the Green Fluorescent Protein (GFP) gene, in the rhizosphere of mung bean plants under drought stress conditions. The transformation of the GFP gene was performed on isolates Bl-19 and Am-7. Seeds were soaked for 30 minutes in bacterial suspensions containing either Bl-19-gfp or Am-7-gfp at a density of 106 cells mL-1, in a volume of 500 mL. The seeds were then planted under drought stress at 60% field ca-pacity and sterile media. The results showed that inoculation of Bl-19-gfp isolates with an initial density of 10⁶ CFU led to a decrease in bacterial density to 1.4 x 10⁵ CFU 1 week after inoculation. Similarly, inoculation of Am-7-gfp isolates with an initial density of 10⁶ CFU caused a decrease to 1.7 x 10⁵ CFU after 1 week of inoculation. Subsequently, the densities of both isolates remained stable from week 2 to week 4. The dry weight of mung bean plants at soil moisture conditions of 60% field capacity using isolates Bl-19 and Am-7 increased by 40.13% and 52.44%, respectively. Based on the results, both isolate increased dry weight below 60% of field capacity in sterile media.