Nakanishi H, Okumura N, Umehara Y, Nishizawa N K, Chino M, Mori S
Laboratory of Plant Nutrition and Fertilizers, University of Tokyo, Japan.
Plant Cell Physiol. 1993 Apr;34(3):401-10.
To clone genes required for the synthesis of mugineic acid (MA) or for the transport of Fe(III)-MA, a lambda ZAPII cDNA library was constructed from poly(A)(+)-RNA isolated from Fe-deficient barley roots. The cDNA library was then used for differential screening of barley roots that had been grown in the presence and absence of iron. Seven clones that hybridized specifically to the probe for Fe deficiency were selected. One clone, presumably encoding a full-length mRNA, as deduced from Northern hybridization, was sequenced. The clone consisting of 1685 nucleotides encoded a putative protein of 169 amino acids and an M(r) of 18704. The gene was specifically expressed in the roots of iron-deficient barley. A search for homologies in a protein database (NBRF) revealed that the predicted protein product has a functional peptide domain that resembles that of 2-oxoglutarate-dependent dioxygenases.
为了克隆麦根酸（MA）合成或铁（III）-麦根酸转运所需的基因，从缺铁大麦根中分离的聚腺苷酸（+）-RNA构建了λZAPII cDNA文库。然后将该cDNA文库用于对在有铁和无铁条件下生长的大麦根进行差异筛选。选择了七个与缺铁探针特异性杂交的克隆。从Northern杂交推断，一个可能编码全长mRNA的克隆被测序。该克隆由1685个核苷酸组成，编码一个推定的169个氨基酸、分子量为18704的蛋白质。该基因在缺铁大麦的根中特异性表达。在蛋白质数据库（NBRF）中搜索同源性发现，预测的蛋白质产物具有一个类似于2-氧代戊二酸依赖性双加氧酶的功能肽结构域。
