采用营养液培养法研究了在不同程度的缺铁条件下 ,大豆 (Glycinemax (L .)Merr .)根系质外体铁库累积与利用的规律 ,及其在缓解植物缺铁胁迫方面的作用。结果表明 :缺铁处理下 ,大豆根系质外体铁库不断被再利用直至枯竭 ,根系还原力与过氧化物酶活性呈升降有序的周期性变化 ,从而一定程度上缓解缺铁胁迫 ,延缓植株缺铁症状的出现 ,新叶叶绿素和活性铁含量缓慢下降 ;而低铁条件下 (供应 10 -6mol/LFeEDTA)大豆根系质外体铁库则呈现累积与利用交替出现的周期性变化 ,同时根系还原力及过氧化物酶活性也呈周期性变化 ,并与质外体铁的周期变化相对应 ,从而满足植株需铁量 ,无明显缺铁症状出现 ,新叶叶绿素与叶片活性铁含量稳定 The nutrient pool culture method was used to study the accumulation and utilization of extracellular body iron pools of soybean (Glycine max (L.) Merr.) Under different levels of iron deficiency and their roles in alleviating iron deficiency in plants. The results showed that under iron deficiency treatment, the exosomal iron pool of soybean root was reused continuously until its exhaustion, and the root reductive potential and peroxidase activity rose periodically and cyclically, which alleviated the iron deficiency stress to a certain extent The emergence of plant iron deficiency decreased chlorophyll and active iron content in new leaves, whereas the cyclical changes in accumulation and utilization of soybean root exosomes in low iron condition (supplying 10 -6 mol / L FeEDTA) Root restitution and peroxidase activities also showed periodic changes and corresponded with the periodic changes of extraneous body iron to meet the requirement of plants for iron deficiency without obvious iron deficiency. The contents of chlorophyll and active iron in new leaves were stable