外源多胺对低氧胁迫下黄瓜幼苗根系生长及H+-ATP酶和H+-焦磷酸酶活性的影响

采用营养液水培方式,研究了根际低氧胁迫下外源多胺对黄瓜幼苗植株根系生长,内源多胺含量与质膜H -ATP酶、液泡膜H -ATP酶和焦磷酸酶活性的影响.结果表明,根际低氧胁迫显著抑制黄瓜幼苗根系的生长,外源Put(腐胺)和Spd(亚精胺)可缓解低氧胁迫对根系的生长抑制,多胺主要以Spd的形式发挥促进性的生理作用,Put通过转化为Spd发挥作用;低氧胁迫下黄瓜根系内源多胺含量略有提高,外源多胺处理可增加内源多胺的含量;低氧胁迫下外源Put和Spd处理后质膜H -ATP酶活性显著提高,外源多胺对黄瓜根系液胞膜H -ATP酶和H -焦磷酸酶活性没有明显影响,说明低氧胁迫下外源多胺主要通过提高质膜H -ATP酶活性而发挥生理作用.

Effects of Exogenous Polyamines on the Growth and Activities of H+-ATPase and H+-PPase in Cucumber Seedling Roots Under Hypoxia Stress

The effects of exogenous polyamines on the growth, polyamines contents, the activi- ties of H+-ATPase and H+-PPase of plasma mem- brane and tonoplast in cucumber seedling roots under root-zone hypoxia stress were studied un- der hydroponic culture. The results showed that the growth of cucumber roots was significantly inhibited by hypoxia stress (Table 1). While the growth inhibition in cucumber roots by hypoxia stress could be alleviated by spraying exogenous polyamines. From these results (Tables 1 and 2) we can conclude that Spd played an active physi- ological role in relieving hypoxia stress and Put exerted actively physiological role by enhanc- ing Spd biosynthesis. The results also showed that the endogenous polyamine contents in cu- cumber roots were increased by hypoxia stressand spraying exogenous polyamines. Exogenous polyamines application obviously promoted the H+-ATPase activities of plasma membrane in cucumber roots (Fig.1), but did not significantly affect the H+-ATPase and H+-PPase activities of tonoplast in cucumber roots (Figs.2,3). The re- sults suggested that exogenous polyamines could enhance hypoxia resistance of cucumber seed- lings by increasing H+-ATPase activities of plasma membrane in cucumber roots.