Modulation of Rhizobacterial Auxin Production at Different pH and Temperature

Abstract

Auxins have been reported to be synthesized by many plant associated bacteria that are involved in enhanced plant growth and root/stem elongation. The aim of the study was to analyze Indole Acetic Acid production by Rhizobacteria at different pH and temperature range. Out of ten isolates, five strains gave a positive primary screening Salkowski test that were proceeded further. Our proposed hypothesis that increasing pH and decreasing temperatures lead to poor production of Auxin was justly supported by the results as all strains showed maximum activity of IAA production at pH 6 among which the most notable strains were AUX-G (36.75 µg/ml) and AUX-M (33.65 µg/ml) with highest IAA production. All strains showed maximum IAA producing activity at 37°C temperature. The least production was associated with decreased temperature i.e. 25° C where AUX-W (2.37 µg/ml) showed the least IAA levels. Hence, maximum IAA yield was obtained at 37°C at 6 pH which also indicated an increased log phase of bacterial growth.