小麦锌营养状况对锌吸收的影响

不论锌的供给形态是无视态(ZnSO_4),还是螯合态(ZnEDTA 或 Zn—PS),小麦锌吸收率均随供锌浓度的提高而增加。缺锌小麦锌吸收率明显高于对照。供ZnEDTA的小麦锌吸收率低于供ZnSO_4和 Zn—PS的小麦。无机态Zn~(24)在根自由空间内累积多,而 ZnEDTA态锌在根自由空间中累积少,缺锌小麦根分泌的有机物质对前者活化量大于后者、被植物吸收利用的数量也就高于后者。

Effect of Zinc Nutritional Status on the Zinc Uptake in Wheat

The effects of zinc nutritional sta-tus on zinc uptake from different formsof zinc and from root apoplast werestudied in wheat (Triticum aestivum L.cv. Ares) in nutrient solutions undercontrolled conditions. The zinc uptake rate was muchhigher in zinc deficient plants than inzinc sufficient plants and increasedgradually with the increase in the con-centrations of zinc, either as inorganicsalt (ZnSO_4) or as a chelate i. e. Zn-phytosiderophres (Zn-PS) orZnEDTA. The uptake rate of zinc byboth zinc-sufficient and zinc-deficientplants was much lower when zinc wassupplied as synthetic chelate(ZnEDTA) than as inorganic salt(ZnSO_4) or chelate of Zn-phy-tosiderophores. This was due to thedifference in the degree of loading rootapoplast with zinc. Large Pools ofapoplasmic Zn were formed after sup-plying ZnSO_4, and much smaller poolswere observed after supplying ZnED-TA or ZnEDTA-NaEDTA. Dependingon zinc nutritional status of plant, theapoplasmic Zn was used to differentextents to be translocated to the shoot,much greater in zinc deficient than Zn-sufficient plants, as a result of the dif-ferent release rate of root exudate.