铅胁迫与黄瓜幼苗生长及内源激素关系的研究

Relationship Between Lead Stress and Growth & Endogenous Phytohormones of Cucumber Seedlings

通过试验利用高效液相色谱(HPLC)对黄瓜幼苗内源激素进行了测定探索,并研究了铅胁迫对黄瓜幼苗生长及内源激素的影响。结果表明:(1)HPLC法测定黄瓜幼苗内源激素的最佳条件为以甲醇、水和2%醋酸为流动相,采用浓度梯度洗脱;(2)低于200mg·L-1铅处理促进黄瓜幼苗生长;300￣900mg·L-1铅处理抑制黄瓜幼苗生长,其抑制作用随铅质量浓度增加而强化,高质量浓度铅处理能诱导不定根形成;(3)根中的脱落酸含量随铅质量浓度的增加而增加,叶和根中玉米素含量随铅质量浓度增加而下降;(4)生长素/脱落酸(IAA/ABA)比值高于对照值对幼苗生长具有激活效应,IAA/ABA比值低于对照值则抑制幼苗生长,表现为毒害效应,此比值可以作为抗重金属毒害的指标之一。

The method of measuring endogenous phytohormones by high performance liquid chromatography （HPLC） and the effects of lead stress on growth and the endogenous phytohormones in cucumber seedlings were studied. The results showed as follows：①the optimal condition of determining endogenous phytohormones by HPLC is gradient elution with mixed running liquid of methanol, water and 2% acetic acid; ②Lead of lower concentration （〈 200 mg. L^-l） promoted the growth of cucumber seedlings, but lead of 300～900 rag. L^-1 restrained the growth and the restraining effect increased with the increasing concentration of Pb^2＋, high concentration of lead induced the formation of adventitious roots. ③The content of ABA in roots increased with the concentration increasing of lead in the treatments, which showed the opposite trend in leaf and root.④The growth promotion was observed when IAA/ABA ratio was higher than the control, but growth inhibition occurred at the ratio of IAA/ABA lower than the control, indicating that the ratio of IAA/ABA may take as an index of toxin immunity to heavy metal.