高pH值和铁素对毛白杜鹃和迎红杜鹃根系Fe~(3+)还原酶活性的影响

以耐碱性不同的两种杜鹃花(毛白杜鹃和迎红杜鹃)的组培苗为材料,对其根系Fe3+还原酶活性与铁素和pH值间的关系进行研究,结果表明:培养最初阶段高pH值(NaHCO3提供)与铁素共同诱导根系Fe3+还原酶活性增加;Fe3+对根系Fe3+还原酶活性的诱导作用具有类似于代谢途径中的底物诱导效应;在10d的缺铁处理中,迎红杜鹃根系Fe3+还原酶活性增加,而毛白杜鹃没有增加,说明缺铁对酶活性的诱导存在种间差异;杜鹃花根系Fe3+还原酶活性与植物耐碱性存在正相关。

THE EFFECTS OF HIGH-pH AND IRON ON ROOT Fe~(3+) REDUCTASE ACTIVITY OF Rhododendron mucronatum AND Rhododendron simsii

The regenerated tissue culture seedlings of Rhododendron mucronatum and R. simsii,which had different alkalinity-tolerance,were used to study the relationship between the root ferric reductase activity and iron and high-pH. The results indicated that:(1) High-pH(provided by NaHCO_3) combined with iron element induced the increase of root ferric reductase activity during the beginning of treatment.The induction of Fe~(3 ) on the root ferric reductase activity was very similar as the effect of substrate induction in some metabolic pathway;(2) The root ferric reductase activity of R.simsii increased,however,that of R. mucronatum didn't increase during ten days Fe-deficiency treatment.This results showed that the induction of the root ferric reductase activity by Fe-deficiency is different between different species;(3) There was positive relativity between root ferric reductase activity and alkalinity-resistance of Rhododendron.