【摘要】 铁离子在植物的生理生化代谢中具有重要的功能.缺铁和铁过量都会对植物造成伤害,因此,维持植物铁离子的动态平衡具有很重要的作用.烟酰胺合成酶基因(NAS)与植物铁离子的吸收转运关系非常密切,但在机理Ⅰ型和机理Ⅱ型植物中,NAS基因的作用机理和表达模式却不同.在双子叶和非禾本科单子叶植物中,烟酰胺(NA)的主要功能是铁离子的储藏和运输,NAS基因的表达不受缺铁胁迫诱导.而在禾本科植物中,NAS基因的表达受缺铁胁迫诱导,并且与铁元素的吸收关系密切.更多还原

【Abstract】 Iron ion plays important roles in plant physiological and biochemical processes. The deficiency or excessive accumulation of iron causes severe damages to plants. Thus,a precise control of iron ion homeostasis in plant is essential for normal cellular function. Nicotianamine synthase gene (NAS) is involved in iron ion absorption and transport. NAS functions differentially between strategyⅠand strategy Ⅱ plants. In dicotyledonous and nongraminaceous plants,NAS synthesizes nicotianamine (NA) which is responsible for iron storage and transportation,and the expression of NAS gene is not induced by iron deficiency. Whereas in graminaceous plants,NAS gene expression is induced by iron deficiency,and is involved in iron uptake .更多还原