Development and marker-trait relationships of functional markers for glutamine synthetase GS1 and GS2 homoeogenes in bread wheat

Abstract

GS1 and GS2 genes encode, respectively, the main cytosolic and the plastidic isoforms of glutamine synthetase (GS). In the present study, the wheat GS1 and GS2 homoeogenes located in the A, B and D genome chromosomes have been sequenced in a group of 15 bread wheat varieties including landraces, old commercial varieties and modern cultivars. Phenotypic characterization by multi-environment field trials detected significant effects of specific GS homoeogenes on three of the seven agronomic and grain quality traits analyzed. Based on the gene sequence polymorphisms found, biallelic molecular markers that could facilitate marker-assisted breeding were developed for genes GS1A, GS2A and GS2D. The remaining genes encoding main wheat GS were excluded because of being monomorphic (GS1D) or too polymorphic (GS1B and GS2B) in the sequencing panel varieties. A collection of 187 Spanish bread wheat landraces was genotyped for these gene-based molecular markers. Data analyses conducted with phenotypic records reported for this germplasm collection in López-Fernández et al. (Plants-Basel 10: 620, 2021) have revealed the beneficial influence of some individual alleles on thousand-kernel weight (TKW), kernels per spike (KS) and grain protein content. Furthermore, genetic interactions between GS1A, a cytosolic GS isoform coding gene, and GS2A or GS2D, plastidic GS enzyme coding genes, were found to affect TKW and KS. The finding that some alleles at one locus may mask the effect of positive alleles at hypostatic GS loci should be kept in mind if gene pyramiding strategies are attempted for the improvement of N-use efficiency-related traits.

Development and application of a codominant marker of the melon rind colour gene CmAPRR2

“…Functional markers (FMs), a type of molecular marker developed based on the variation of cloned functional genes, are completely associated with the target trait and, therefore, have great superiority. Functional genetic markers can reduce the genetic burden of progeny selection, greatly improving selection accuracy (Pascual et al, 2023). Currently, multiple melon genomes have been assembled and annotated, and some genes controlling important agronomic traits of melons have been cloned (Ma et al, 2022).…”

Genome-Wide Identification and Expression Analysis of Gs and Gogat Gene Family in Pecan (<em>Carya illinoinensis</em>) under Different Nitrogen Forms

“…GS is a key enzyme involved in NH4 + , which can convert inorganic ammonium salts in plant into organic N [12]. Studies have shown that the role of GS activity in response to fertilization has been widely investigated, and its relationship with stresses such as drought and high temperature has also been explored [13]. In most plants, GS exists in two forms, including cytoplasmic GS1 and chloroplasts GS2 [14].…”