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

Abstract

In the present study, three chromium resistant bacterial strains (CrT-1, CrT-2, CrT-3) which could resist very<br />high concentration of K2CrO4 (up to 40 mg ml-1 on nutrient agar plates and 10 mg ml-1 in acetate-minimal<br />medium) were used to inoculate the sunflower seeds both as control and under chromium stress. Cr(VI)<br />caused severe reduction in different growth parameters (seedling length, fresh weight, dry weight g-1 fresh<br />weight) as compared to control, while bacterial inoculations improved different growth parameters both as<br />control and under chromate stress when compared with non-inoculated respective controls. With respect<br />to biochemical parameters, acid phosphatase and auxin content showed marked increment with bacterial<br />inoculation both in chromium stress and unstressed condition. Uptake of chromium in inoculated plants<br />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<br />also prevent cell damages caused by the Cr (VI) salt.<br /><br />