The use of Tn5-mutants Bradyrhyzobium japonicum for regulation of prooxidant-antioxidant processes in soybean plants under drought condition

Abstract

Aim. To investigate the use of soybean seed inoculation by nodule bacteria obtained by transposon mutagenesis to ensure the effective formation and functioning of symbiotic systems by regulating prooxidant - antioxidant processes and reducing the negative effects of drought on crop productivity. Methods. Microbiological, physiological, biochemical methods, gas chromatography and spectrophotometry. Results. It has been proved that due to the activation of protective antioxidant enzymes of catalase, ascorbate and guaiacol peroxidase in soybean roots and root nodules, adaptive rearrangements of plant metabolism occur aimed at stabilizing the content of prooxidants, hydrogen peroxide, in drought conditions. At the same time, the specific nitrogen-fixation activity of soybean root nodules undergoes no significant changes and indicates the preservation of the effective functioning of the symbiotic apparatus, is the result of activation of protective antioxidant processes and adaptation of the soybean symbiotic system with the participation of Tn-5 mutant Bradyrhizobium japonicum B1-20 to dehydration conditions. Conclusions. The use of inoculation of soybean seeds with the Tn-5 mutant Bradyrhizobium japonicum B1-20 leads to regulation of prooxidant - antioxidant protective processes in plants, helps to increase their nitrogen-fixation potential and maintain grain yield under prolonged exposure to drought. Keywords: soybean (Glycine max (L.) Merr.), hydrogen peroxide, catalase, ascorbate peroxidase, guaiacol peroxidase, drought.