Study of the Effect of Trifluraline on the Oxidation and the Denaturation Constant of Soy Bean Lba~(3+)

摘要

The haem denaturation constants of native (control) and experimental Lba~(3+) isolated from nodules of the "Williams" soy bean variety grown in untreated and treated with 2.1 X 10~(-10) mol dm~(-3) trifluraline (in vivo experiment) soil have been measured after oxidation with H_2O_2 in concentrations five times higher than that of the haem. The denaturation constant of Lba~93+) (4.5 X 10~(-3) mmol dm~(-3)) has been also evaluated in vitro experiment, i.e. after its preliminary treatment with trifluraline (3.2 X 10~(-8) mmol dm~(-3)) resulting to the formation of a complex between trifluraline and Lba~(3+). The results show that the native Lba~(3+) haem is readily denaturated - 1.7 X 10~(-3) s~(-1). The trifluraline containing Lba~(3+) from both in vivo and in vitro experiments has a lower value of the denaturation constant - 1.3 X 10~(-3) s~(-1) and 1.2 X 10~(-3) s~(-1). The deceleration of the denaturation processes of Lba~(3+) haem can affect the inhibition of the senescence process in the soy bean nodules, which is of physiological significance for the nitrogen-fixation process in the soy bean plants.