Growth improvements of Sunflower seedlings by Cr(VI)-resistant bacteria

Document Type : Research Paper


Department of Botany, Faculty of Agriculture, University of the Punjab, Quaid-e-Azam Campus, Lahore-54590, Pakistan.


In the present study, three chromium resistant bacterial strains (CrT-1, CrT-2, CrT-3) which could resist very
high concentration of K2CrO4 (up to 40 mg ml-1 on nutrient agar plates and 10 mg ml-1 in acetate-minimal
medium) were used to inoculate the sunflower seeds both as control and under chromium stress. Cr(VI)
caused severe reduction in different growth parameters (seedling length, fresh weight, dry weight g-1 fresh
weight) as compared to control, while bacterial inoculations improved different growth parameters both as
control and under chromate stress when compared with non-inoculated respective controls. With respect
to biochemical parameters, acid phosphatase and auxin content showed marked increment with bacterial
inoculation both in chromium stress and unstressed condition. Uptake of chromium in inoculated plants
decreased significantly as compared to non-inoculated control. Cr (VI) application also severely damages different plant cells/tissues but bacterial inoculation not only improves the growth and yields parameters but
also prevent cell damages caused by the Cr (VI) salt.