Schnorr K M, Laloue M, Hirel B
Laboratoire de Biologie Cellulaire, INRA, Centre de Versailles, Versailles, France.
Plant Mol Biol. 1996 Nov;32(4):751-7. doi: 10.1007/BF00020216.
Soybean nodule cDNA clones encoding glycinamide ribonucleotide (GAR) synthetase (GMpurD) and GAR transformylase (GMpurN) were isolated by complementation of corresponding Escherichia coli mutants. GAR synthetase and GAR transformylase catalyse the second and the third steps in the de novo purine biosynthesis pathway, respectively. One class of GAR synthetase and three classes of GAR transformylase cDNA clones were identified. Northern blot analysis clearly shows that these purine biosynthetic genes are highly expressed in young and mature nodules but weakly expressed in roots and leaves. Expression levels of GMpurD and GMpurN mRNAs were not enhanced when ammonia was provided to non-nodulated roots.
通过互补相应的大肠杆菌突变体，分离出了编码甘氨酰胺核糖核苷酸（GAR）合成酶（GMpurD）和GAR转甲酰基酶（GMpurN）的大豆根瘤cDNA克隆。GAR合成酶和GAR转甲酰基酶分别催化从头嘌呤生物合成途径中的第二步和第三步。鉴定出了一类GAR合成酶和三类GAR转甲酰基酶cDNA克隆。Northern印迹分析清楚地表明，这些嘌呤生物合成基因在幼嫩和成熟根瘤中高度表达，但在根和叶中表达较弱。当向未结瘤的根提供氨时，GMpurD和GMpurN mRNA的表达水平没有增强。
