Bertelsen H
Department of Molecular Biology and Plant Physiology, University of Aarhus, DK-8000 Aarhus C, Denmark.
Plant Physiol. 1985 Feb;77(2):335-8. doi: 10.1104/pp.77.2.335.
Nitrogenase (EC 1.7.99.2) activity in pea (Pisum savitum) nodules formed after infection with Rhizobium leguminosarum (lacking uptake hydrogenase) was measured as acetylene reduction, H(2) evolution in air and H(2) evolution in Ar:O(2). With detached roots the relative efficiency, calculated from acetylene reduction, showed a decrease (from 55 to below 0%) with increasing temperature. With excised nodules and isolated bacteroids similar results were obtained. However, the relative efficiency calculated from H(2) evolution in Ar:O(2) was unaffected by temperature. Measurements on both excised nodules and isolated bacteroids showed a marked difference between acetylene reduction and H(2) evolution in Ar:O(2) with increased temperature, indicating that either acetylene reduction or H(2) evolution in Ar:O(2) are inadequate measures of nitrogenase activity at higher temperature.
用乙炔还原法、在空气中的氢气释放量以及在氩气:氧气中的氢气释放量来测定豌豆(Pisum savitum)根瘤在被缺乏吸氢酶的豌豆根瘤菌感染后形成的固氮酶(EC 1.7.99.2)活性。对于离体根,根据乙炔还原计算出的相对效率随着温度升高而降低(从55%降至0%以下)。对于切除的根瘤和分离的类菌体,也得到了类似结果。然而,根据在氩气:氧气中的氢气释放量计算出的相对效率不受温度影响。对切除的根瘤和分离的类菌体的测量表明,随着温度升高,乙炔还原和在氩气:氧气中的氢气释放量之间存在显著差异,这表明在较高温度下,乙炔还原或在氩气:氧气中的氢气释放量都不是固氮酶活性的充分衡量指标。