Antioxidative enzymes from chloroplasts, mitochondria, and peroxisomes during leaf senescence of nodulated pea plants.
In this work the influence of the nodulation of pea (Pisum sativum L.) plants on the oxidative metabolism of different leaf organelles from young and senescent plants was studied. Chloroplasts, mitochondria, and peroxisomes were purified from leaves of nitrate-fed and Rhizobium leguminosarum-nodulated pea plants at two developmental stages (young and senescent plants). In these cell organelles, the activity of the ascorbate-glutathione cycle enzymes ascorbate peroxidase (APX), monodehydroascorbate reductase (MDHAR), dehydroascorbate reductase (DHAR), and glutathione reductase (GR), and the ascorbate and glutathione contents were determined. In addition, the total superoxide dismutase (SOD) activity, the pattern of mitochondrial and peroxisomal NADPH-generating dehydrogenases, some of the peroxisomal photorespiratory enzymes, the glyoxylate cycle and oxidative metabolism enzymes were also analysed in these organelles. Results obtained on the metabolism of cell organelles indicate that nodulation with Rhizobium accelerates senescence in pea leaves. A considerable decrease of the ascorbate content of chloroplasts, mitochondria, and peroxisomes was found, and in these conditions a metabolic conversion of leaf peroxisomes into glyoxysomes, characteristic of leaf senescence, took place.
Palma
José M
JM
Departamento de Bioquímica, Biología Celular y Molecular de Plantas, Estación Experimental del Zaidín, CSIC, Apartado 419, 18080 Granada, Spain. jmpalma@eez.csic.es
Jiménez
Ana
A
Sandalio
Luisa M
LM
Corpas
Francisco J
FJ
Lundqvist
Marianne
M
Gómez
Manuel
M
Sevilla
Francisca
F
del Río
Luis A
LA
D000375:Aging / Q000378:metabolism*; D000975:Antioxidants / Q000378:metabolism*; D001205:Ascorbic Acid / Q000378:metabolism; D002736:Chloroplasts / Q000201:enzymology / Q000378:metabolism; D005978:Glutathione / Q000378:metabolism; D008928:Mitochondria / Q000201:enzymology / Q000378:metabolism; D009584:Nitrogen / Q000378:metabolism; D009586:Nitrogen Fixation / Q000502:physiology; D015388:Organelles / Q000201:enzymology* / Q000378:metabolism; D018532:Pisum sativum / Q000201:enzymology* / Q000378:metabolism / Q000502:physiology; D020675:Peroxisomes / Q000201:enzymology / Q000378:metabolism; D018515:Plant Leaves / Q000201:enzymology* / Q000378:metabolism; D016961:Rhizobium leguminosarum / Q000502:physiology
D000975:Antioxidants; D005978:Glutathione; D009584:Nitrogen; D001205:Ascorbic Acid