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The antioxidants of legume nodule mitochondria.
Mol Plant Microbe Interact. 2001 Oct; 14(10):1189-96.MP

Abstract

The mitochondria of legume root nodules are critical to sustain the energy-intensive process of nitrogen fixation. They also generate reactive oxygen species at high rates and thus require the protection of antioxidant enzymes and metabolites. We show here that highly purified mitochondria from bean nodules (Phaseolus vulgaris L. cv. Contender x Rhizobium leguminosarum bv. phaseoli strain 3622) contain ascorbate peroxidase primarily in the inner membrane (with lesser amounts detected occasionally in the matrix), guaiacol peroxidases in the outer membrane and matrix, and manganese superoxide dismutase (MnSOD) and an ascorbate-regenerating system in the matrix. This regenerating system relies on homoglutathione (instead of glutathione) and pyridine nucleotides as electron donors and involves the enzymes monodehydroascorbate reductase, dehydroascorbate reductase, and homoglutathione reductase. Homoglutathione is synthesized in the cytosol and taken up by the mitochondria and bacteroids. Although bacteroids synthesize glutathione, it is not exported to the plant in significant amounts. We propose a model for the detoxification of peroxides in nodule mitochondria in which membrane-bound ascorbate peroxidase scavenges the peroxide formed by the electron transport chain using ascorbate provided by L-galactono-1,4-lactone dehydrogenase in the inner membrane. The resulting monodehydroascorbate and dehydroascorbate can be recycled in the matrix or cytosol. In the matrix, the peroxides formed by oxidative reactions and by MnSOD may be scavenged by specific isozymes of guaiacol peroxidase, ascorbate peroxidase, and catalase.

Authors+Show Affiliations

Departamento de Nutrición Vegetal, Estación Experimental de Aula Dei, CSIC, Zaragoza, Spain.No affiliation info availableNo affiliation info availableNo affiliation info availableNo affiliation info available

Pub Type(s)

Journal Article
Research Support, Non-U.S. Gov't
Research Support, U.S. Gov't, Non-P.H.S.

Language

eng

PubMed ID

11605958

Citation

Iturbe-Ormaetxe, I, et al. "The Antioxidants of Legume Nodule Mitochondria." Molecular Plant-microbe Interactions : MPMI, vol. 14, no. 10, 2001, pp. 1189-96.
Iturbe-Ormaetxe I, Matamoros MA, Rubio MC, et al. The antioxidants of legume nodule mitochondria. Mol Plant Microbe Interact. 2001;14(10):1189-96.
Iturbe-Ormaetxe, I., Matamoros, M. A., Rubio, M. C., Dalton, D. A., & Becana, M. (2001). The antioxidants of legume nodule mitochondria. Molecular Plant-microbe Interactions : MPMI, 14(10), 1189-96.
Iturbe-Ormaetxe I, et al. The Antioxidants of Legume Nodule Mitochondria. Mol Plant Microbe Interact. 2001;14(10):1189-96. PubMed PMID: 11605958.
* Article titles in AMA citation format should be in sentence-case
TY - JOUR T1 - The antioxidants of legume nodule mitochondria. AU - Iturbe-Ormaetxe,I, AU - Matamoros,M A, AU - Rubio,M C, AU - Dalton,D A, AU - Becana,M, PY - 2001/10/19/pubmed PY - 2002/5/22/medline PY - 2001/10/19/entrez SP - 1189 EP - 96 JF - Molecular plant-microbe interactions : MPMI JO - Mol Plant Microbe Interact VL - 14 IS - 10 N2 - The mitochondria of legume root nodules are critical to sustain the energy-intensive process of nitrogen fixation. They also generate reactive oxygen species at high rates and thus require the protection of antioxidant enzymes and metabolites. We show here that highly purified mitochondria from bean nodules (Phaseolus vulgaris L. cv. Contender x Rhizobium leguminosarum bv. phaseoli strain 3622) contain ascorbate peroxidase primarily in the inner membrane (with lesser amounts detected occasionally in the matrix), guaiacol peroxidases in the outer membrane and matrix, and manganese superoxide dismutase (MnSOD) and an ascorbate-regenerating system in the matrix. This regenerating system relies on homoglutathione (instead of glutathione) and pyridine nucleotides as electron donors and involves the enzymes monodehydroascorbate reductase, dehydroascorbate reductase, and homoglutathione reductase. Homoglutathione is synthesized in the cytosol and taken up by the mitochondria and bacteroids. Although bacteroids synthesize glutathione, it is not exported to the plant in significant amounts. We propose a model for the detoxification of peroxides in nodule mitochondria in which membrane-bound ascorbate peroxidase scavenges the peroxide formed by the electron transport chain using ascorbate provided by L-galactono-1,4-lactone dehydrogenase in the inner membrane. The resulting monodehydroascorbate and dehydroascorbate can be recycled in the matrix or cytosol. In the matrix, the peroxides formed by oxidative reactions and by MnSOD may be scavenged by specific isozymes of guaiacol peroxidase, ascorbate peroxidase, and catalase. SN - 0894-0282 UR - https://www.unboundmedicine.com/medline/citation/11605958/The_antioxidants_of_legume_nodule_mitochondria_ L2 - https://apsjournals.apsnet.org/doi/abs/10.1094/MPMI.2001.14.10.1189?url_ver=Z39.88-2003&rfr_id=ori:rid:crossref.org&rfr_dat=cr_pub=pubmed DB - PRIME DP - Unbound Medicine ER -