Department of Agro-Forestry and Environmental Biology and Chemistry, University of Bari, Via Amendola 165/A, Bari, Italy.
Funct Integr Genomics. 2011 Dec;11(4):665-70. doi: 10.1007/s10142-011-0235-2. Epub 2011 Jul 14.
Glutamine synthetase (GS2) is a key enzyme in plant nitrogen metabolism responsible of the first step of ammonium assimilation and transformation into glutamine (an essential compound in the amino acid-biosynthetic pathway). The goal of the present study was to isolate and characterize GS2 genes and to assess the linkage with grain protein content (GPC), an important quantitative trait controlled by multiple genes. Here, we report the isolation of the complete glutamine synthetase gene sequences and their localization on the two homeologous chromosome 2A and 2B in durum wheat cvs. Ciccio and Svevo characterized by a different grain protein content. GS2-A2 located on 2A chromosome is comprised of 13 exons separated by 12 introns, and the allele sequence in the two cultivars were different for an insertion of 5 bp located in the third exon in the cv. Ciccio. The GS2-B2 has the same intron/exon structure, but the two cultivars differ for the insertion of a 33-bp sequence located in the second intron of the cv. Svevo. Specific primers were designed in the polymorphic region and amplified in a recombinant inbred line mapping population. The study localized GS genes (GS2-A2, GS2-B2 GSe, GSr) on chromosomes 2A, 2B, 4A, and 4B, where four significant QTLs for GPC were also located.
谷氨酰胺合成酶（GS2）是植物氮代谢中的一种关键酶，负责氨同化和转化为谷氨酰胺的第一步（氨基酸生物合成途径中的一种必需化合物）。本研究的目的是分离和鉴定 GS2 基因，并评估其与粒蛋白含量（GPC）的连锁关系，GPC 是一个由多个基因控制的重要数量性状。在这里，我们报告了完整的谷氨酰胺合成酶基因序列的分离及其在硬粒小麦品种 Ciccio 和 Svevo 的同源染色体 2A 和 2B 上的定位，这两个品种的粒蛋白含量不同。位于 2A 染色体上的 GS2-A2 由 13 个外显子和 12 个内含子组成，两个品种的等位基因序列在第三个外显子中存在 5bp 的插入。GS2-B2 具有相同的内含子/外显子结构，但两个品种在 Svevo 的第二个内含子中存在 33bp 序列的插入。在多态性区域设计了特异性引物，并在重组自交系作图群体中进行了扩增。研究将 GS 基因（GS2-A2、GS2-B2、GSe、GSr）定位在染色体 2A、2B、4A 和 4B 上，这些染色体上还定位了四个与 GPC 相关的显著 QTL。
