Skrdleta V, Gaudinová A, Nĕmcová M, Hyndráková A
Folia Microbiol (Praha). 1980;25(2):155-61. doi: 10.1007/BF02933016.
Effect of nitrate on the nitrogenase (C2H2-reduction) activity, growth of nodule tissue accumulation of nitrate and nitrate reductase activity in 4-weeks-old nodulated peas (Pisum sativum L.) was investigated. A relatively slow decrease of the total nitrogenase activity (mumol C2H4 per root per h), as compared with plants cultivated without nitrate, was due to both retardation of further growth of the nodule tissue and to a decrease of their specific nitrogenase activity (mumol C2H4 per gf.wt. per h). However, an absolute and pronounced decrease of both nitrogenase activities occurred only 4 or 7 d after the application of nitrate. The addition of nitrate led to its rapid accumulation in the nodule and leaf tissue with a simultaneous induction of the nitrate reductase activity. The nitrogenase activity was not completely inhibited even after a 7-d cultivation with 280 m NO3- -N in the nutrient medium and after accumulation of up to 180 ppm NO3- -Nf.wt. in the nodule tissue. The results obtained indicate that the "photosynthate deprivation" reflects competition between assimilation of nitrate and fixation of dinitrogen.
研究了硝酸盐对4周龄结瘤豌豆（Pisum sativum L.）的固氮酶（C2H2还原）活性、根瘤组织生长、硝酸盐积累以及硝酸还原酶活性的影响。与不添加硝酸盐培养的植株相比，总固氮酶活性（每根每小时μmol C2H4）相对缓慢下降，这是由于根瘤组织进一步生长受阻以及其比固氮酶活性（每克鲜重每小时μmol C2H4）降低所致。然而，仅在施加硝酸盐4天或7天后，固氮酶活性才出现绝对且明显的下降。添加硝酸盐导致其在根瘤和叶片组织中迅速积累，同时诱导硝酸还原酶活性。即使在营养培养基中含有280 mM NO3--N培养7天以及根瘤组织中积累高达180 ppm NO3--N鲜重后，固氮酶活性也未被完全抑制。所得结果表明，“光合产物剥夺”反映了硝酸盐同化与二氮固定之间的竞争。
