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Acetylene reduction and respiration of bacteroids isolated from French‐beans receiving nitrate
Author(s) -
Trinchant JeanCharles,
Rigaud Jean
Publication year - 1981
Publication title -
physiologia plantarum
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.351
H-Index - 146
eISSN - 1399-3054
pISSN - 0031-9317
DOI - 10.1111/j.1399-3054.1981.tb02742.x
Subject(s) - nitrogenase , acetylene , nitrate , respiration , nitrogen fixation , oxygen , nitrogen , chemistry , agronomy , horticulture , biology , botany , organic chemistry
The competition between combined nitrogen and nitrogen fixation in legumes was studied after a 24 h exposure of nodulated French‐beans to nitrate. Acetylene reduction by bacteroids was significantly inhibited and even nitrogenase extracted from nitrate‐treated plant nodules showed reduced activity. Sensitivity to nitrate was directly related to nodule age and also increased with increasing oxygen tensions in the bacteroid incubations with or without a gas phase; it was particularly marked when glucose was used in place of succinate as energy‐yielding substrate. Bacteroid respiration was also depressed by nitrate‐treatment of the plants, leading to diminished acetylene reduction and this effect increased with increasing oxygen concentrations. Added oxyleghemoglobin partly restored oxygen consumption and acetylene reduction by bacteroid suspensions.