利用铁-铜拮抗作用减少玉米铜毒害的研究

Alleviation of Cu Phyto-toxicity on Maize by Antagonism Between Fe and Cu

采用水培试验方法,研究了缺铁和供铁条件下玉米幼苗对不同形态铜的吸收特征以及不同浓度铜和不同形态铜对玉米幼苗吸收铁的影响。结果表明,缺铁条件下,玉米幼苗吸收铜的量随着铜浓度的升高显著增加,根系铜含量和积累的铜量显著高于地上部的铜含量和积累量。无机铜是最容易被玉米幼苗吸收的形态,而且向地上部的转运也最多。在有机络合铜中,EDTA络合铜被吸收的量最少,但在体内向地上部的相对转运比例最大。有机络合铜被吸收的总量虽然较大,但多积累于根部,向地上部运输的比例很小。增加铁的使用可以大大减少进入植物体内的铜量,并使已进入植物根系的铁更多地分布在根部,从而减少了地上部铜的含量和铜的毒害。铁存在对无机铜吸收的抑制作用最大,其次是酒石酸铜、苹果酸铜、柠檬酸铜、草酸铜,而对EDTA-铜的吸收抑制最小。

Uptake characters of different copper forms by young maize plant underwent treatments with either Fe deficiency or sufficiency were studied by hydroponic culture. Furthermore, we studied effects on Fe uptake by young plant of maize under different concentrations and different forms of Cu. The results showed that, Cu contents in the plant were higher with increasing Cu concentration under Fe deficiency treatment, and the contents of Cu in roots were notably higher than shoots. Inorganic Cu was the easiest uptake by young plant of maize, and most of Cu contents were transferred to shoots. Among the five different Cu forms treatments, the contents of Cu were in the lowest in young maize plant, but the relative contents of Cu ＂by transferred to shoots were in the highest under EDTA-Cu treatment. The total Cu contents were in the highest by the plant assimilated under five different organic complex Cu treatments than inorganic Cu treatment, and they all were accumulated in roots, but the transfer proportion to shoots were lower. Increasing ion could visibly decrease Cu contents in the plant, and more Cu contents stayed in roots, but less was transferred to shoots, so organic complex Cu could decrease phyto-toxicity to young maize plant. Inorganic Fe exhibited the biggest inhibiting effect on Cu contents by young maize plant assimilated, and subsequently was tartrate -Cu, malate-Cu, citrate-Cu, oxalate-Cu, and EDTA-Cu had the smallest inhibiting effect on Cu contents.