锌营养状况对小麦根细胞膜透性的影响

小麦缺锌不仅导致根系K~ 和NO_3~-泌出量增加,而且低分子量有机化合物如氨基酸、糖类化合物和酚类化合物的泌出量也明显提高。重新供锌(ZnSO_4)12h后,根系K~ 、NO_3~-、氨基酸和碳水化合物的泌出量迅速减少,随着时间的延长,泌出量接近对照水平。结果说明锌对根细胞膜结构的稳定性及膜功能的完整性是必不可少的。

Effect of Zinc Nutritional Status on Membrane Permeability in Wheat Roots

The effect of zinc nutritional status on root membrane permeability was studied in wheat (Triticum aestivum L. cv Ares) in nutrient solutions under controlled conditions. Root exudation as art indicator for root membrane permeability was measured when roots of intact plants were incubated in aerated CaCl_2 (0.5 mmol/L) solution. Zinc deficiency enhanced the increase in the exudation of K~ , NO_3~-, amino acids, sugars and phenolics. This increase in the root exudation, was closely related to zinc nutritional status of plants. Resupply of zinc to zinc deficient plants for 12, 24, 36 and 72 h decreased the root exudation of K~ , NO_3~-, amino acids and sugaas. These results indicated a distinct role of zinc in membrane integrity and permeability which was discussed n regard to the effect of zinc on the production of radicals and their oxidative damage to cell membrane.