Oxidative stress occurs during soybean nodule senescence

Abstract

Several markers of oxidative stress were measured in 2-to 10-week-old soybean (Glycine max [L.] Merr.) nodules. There were increases in peroxides, protein carbonyls and modi®ed DNA base concentrations with nodule age. The catalytic iron content also increased signi®cantly during nodule ageing. Iron contained in the peribacteroid space was eective in promoting lipid peroxidation and this might contribute to the degradation of the peribacteroid membrane in senescing nodules. The concentration of the oxidized forms of glutathione and homoglutathione increased signi®cantly during nodule development and the concentration of reduced glutathione and homoglutathione decreased during senescence. Taken together, these results are consistent with the development of oxidative stress in senescing nodules. Signi®cant DNA and protein damage also occurred in the ®rst days of nodule development, suggesting that an earlier period of oxidative stress might occur in the period over which the symbiosis becomes established.Abbreviations: CHP = cumene hydroperoxide; GSH = glutathione; hGSH = homoglutathione; MDA = malondialdehyde; PBM = peribacteroid membrane; PBS = peribacteroid space; ROS = reactive oxygen species Correspondence to: A. Puppo;

The Response of Carbon Metabolism and Antioxidant Defenses of Alfalfa Nodules to Drought Stress and to the Subsequent Recovery of Plants

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Posttranslational control of transcription factor FixK 2 , a key regulator for the Bradyrhizobium japonicum –soybean symbiosis

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Role of the extracytoplasmic function sigma factor CarQ in oxidative response of Bradyrhizobium japonicum

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