Iron Uptake in Arabidopsis thaliana

9318093 Guerinot铁是所有高等植物的必需营养素，含铁化合物在光合作用和呼吸作用的电子传递系统中起重要作用。 虽然铁在土壤中是丰富的，铁的收购是有问题的，由于其在生物pH值在有氧条件下的低溶解度。 利用生物化学、遗传学和分子遗传学技术，在模式植物系统拟南芥中研究铁的吸收机制。 重点是发生在根表面的三价铁的还原，因为三价铁的还原可能是使铁可用于植物吸收的主要因素。 主要目的是确定基因编码的铁还原酶活性所必需的组件。 将同时采用三种策略来鉴定这些基因：a）使用来自酵母的FRE 1基因来鉴定拟南芥同源物; B）互补fre 1 -1酵母突变体来鉴定拟南芥同源物;和c）鉴定具有改变的三价铁还原酶活性的拟南芥突变体，并使用这些突变体来克隆参与三价铁还原的基因。 拟南芥铁吸收的研究应适用于一般的跨膜渗透过程及其调控，并可能最终导致铁高效植物品种的建设。 这些研究也将有助于阐明根特异性基因表达和金属对基因表达的调控。 ***

9318093 Guerinot Iron is an essential nutrient for all higher plants, with iron- containing compounds figuring prominently in the electron transport systems of photosynthesis and respiration. Although iron is abundant in the soil, the acquisition of iron is problematic due to its low solubility at biological pH under aerobic conditions. Iron uptake mechanisms are being studied in the model plant system, Arabidopsis thaliana, using biochemical, genetic and molecular genetic techniques. The focus is on the reduction of ferric iron which takes place at the root surface because ferric reduction is probably the primary factor in making iron available for absorption by plants. The main objective is to identify genes which encode components necessary for ferric reductase activity. Three strategies to identify such genes will be pursued simultaneously: a) use of the FRE1 gene from yeast to identify an Arabidopsis homolog; b) complementation of the fre1-1 yeast mutant to identify an Arabidopsis homolog; and c) identification of Arabidopsis mutants with altered ferric reductase activity and use of such mutants to clone the gene(s) involved in ferric reduction. A study of iron uptake in Arabidopsis should have application to general transmembrance permeation processes and their regulation and may ultimately lead to the construction of iron efficient plant varieties. These studies should also shed light on root specific gene expression and the regulation of gene expression by metals. ***