亚精胺浸种对玉米幼苗根尖线粒体ATPase活性与结合态亚精胺含量的影响

Effect of Seed Soaking with Spermidine on ATPase Activity and Conjugated Polyamine Content in Mitochondria Membrane of Maize Seedling Root under Osmotic Stress

以抗旱性不同的玉米品种农大108(抗旱性较强)和掖单13(抗旱性较弱)为材料,经过亚精胺(Spd)浸种处理,研究在聚乙二醇(PEG)-6000渗透胁迫下,幼苗根尖线粒体ATPase水解活性与膜上非共价结合态多胺含量的关系。结果表明,渗透胁迫条件下,抗性强的农大108的ATPase活性下降的幅度明显小于抗性弱的品种掖单13,而农大108的线粒体膜上非共价结合态亚精胺的上升幅度明显大于掖单13。亚精胺浸种处理,明显增强了掖单13幼苗的抗性,促进了掖单13在胁迫条件下非共价结合态Spd含量的增加,同时抑制其在胁迫条件下ATPase活性的降低。这些结果表明,亚精胺浸种处理,通过提高玉米幼苗根尖线粒体膜上的非共价结合态Spd含量,维持ATPase活性的稳定,从而提高玉米幼苗的抗渗透胁迫能力。

Two maize（Zea mays L. ）cultivars, Nongda 108 （drought-tolerant） and Yedan 13 （drought-sensitive） were selected to investigate the effects of seed soaking with spermidine on ATPase activity and conjugated-polyamine contents in mitochondria membrane of seedling roots under osmotic stress. The result showed that, in 7 days after polyethylene glycol（PEG）-6000 treatment, the ATPase activity decreased more in Yedan 13 than in Nongda 108, while the con- tent of noncovalently eonjugated-spermidine （Spd） increased more in Nongda 108 than in Yedan 13. Under osmotic stress, seed soaking with spermidine could obviously increase the noncova- lently conjugated-Spd level and inhibit the decrease of ATPase activity in Yedan 13, so as to en- hance its tolerance to stress. The results suggested that Spd seed-soaking could enhance the tolerance of maize seedlings to osmotic stress, especially for the drought-sensitive cultivar, by increasing the noncovalently conjugated-Spd level and maintaining the stability of ATPase activity in mito- ehondria membrane.