【摘要】 通过水培试验研究了打顶后烟株喷施2,4-D对烟株根中合成烟碱的关键酶鸟氨酸脱羧酶(ODC)、腐胺N-甲基转移酶(PMT)和N-甲基腐胺氧化酶(MPO)以及碳氮代谢重要转化酶(InV)和硝酸还原酶(NR)的活性及烟叶中烟碱含量和钾含量的影响。结果表明,喷施2,4-D的烟叶与对照相比InV活性降低,NR活性升高,协调了烟叶的碳氮代谢,根系活力降低,抑制烟株根中合成烟碱的3种酶活性,减少烟叶中的烟碱积累,同时提高烟叶中钾含量。2,4-D降碱增钾效果的最适宜浓度分别为20 mg/kg和30 mg/kg。更多还原

【Abstract】 Solution pot experiments were conducted to study the effects of 2,4-D on the activities of nitrate reductase(NR),invertase(InV),ornithine decarboxylase(ODC),putrescine N-methyl transferase(PMT),and N-methyl-putrescine oxidase(MPO),and on the contents of nicotine and potassium in flue-cured tobacco.The results showed that,by spraying 2,4-D on tobacco leaves after topping,leaf InV activity decreased,NR activity increased,carbon-nitrogen metabolism was better balanced,root activity decreased,three enzyme activities in nicotine synthesis of tobacco roots were constrained,nicotine accumulation decreased,and potassium content in tobacco leaves increased.The optimum 2,4-D concentrations were 20 mg/kg and 30 mg/kg for decreasing nicotine content and increasing potassium content,respectively.更多还原