2024-03-28T19:00:45Zhttp://digital.csic.es/dspace-oai/requestoai:digital.csic.es:10261/54352016-11-14T11:56:05Zcom_10261_75com_10261_6col_10261_328
00925njm 22002777a 4500
dc
Escuredo, Pedro R.
author
Minchin, Frank R.
author
Gogorcena Aoiz, Yolanda
author
Iturbe-Ormaetxe, IƱaki
author
Klucas, R. V.
author
Becana Ausejo, Manuel
author
1996-04
The effect of short-term nitrate application (10 mM, 0-4 d) on nitrogenase (N2ase) activity, antioxidant defenses, and related parameters was investigated in pea (Pisum sativum L. cv Frilene) nodules. The response of nodules to nitrate comprised two stages. In the first stage (0-2 d), there were major decreases in N2ase activity and N2ase-linked respiration and concomitant increases in carbon cost of N2ase and oxygen diffusion resistance of nodules. There was no apparent oxidative damage, and the decline in N2ase activity was, to a certain extent, reversible. The second stage (>2 d) was typical of a senescent, essentially irreversible process. It was characterized by moderate increases in oxidized proteins and catalytic Fe and by major decreases in antioxidant enzymes and metabolites. The restriction in oxygen supply to bacteroids may explain the initial decline in N2ase activity. The decrease in antioxidant protection is not involved in this process and is not specifically caused by nitrate, since it also occurs with drought stress. However, comparison of nitrate- and drought-induced senescence shows an important difference: there is no lipid degradation or lipid peroxide accumulation with nitrate, indicating that lipid peroxidation is not necessarily involved in nodule senescence.
Plant Physiol. 1996 Apr;110(4):1187-1195
0032-0889
http://hdl.handle.net/10261/5435
Involvement of Activated Oxygen in Nitrate-Induced Senescence of Pea Root Nodules