Identification and Expression Analysis of Glutamine Synthetase Genes in Ramie (Boehmeria nivea L. Gaud)

Abstract

Glutamine synthetase (GS) plays a fundamental role in nitrogen metabolism in higher plants. Three BnGS genes have first been isolated: one gene encoding plastid GS (BnGS2) and two encoding cytosolic GS (BnGS1-1 and BnGS1-2) in ramie. Based on a sequence analysis and phylogenetic study, three BnGS sequences were classified into three distinct sub-families. The phylogenetic analysis showed that BnGS2 and BnGS1-2 were closely related to those of legumes, alfalfa (Medicago sativa), soybean (Glycine max) and bean (Phaseolus vulgaris). The BnGS gene expression patterns revealed that each gene exhibited similar organ specificity, but distinct transcript intensity during different vegetative processes. The relatively abundant expression of BnGS1-1 and BnGS2 at specific organs during different vegetative processes indicates that they have critical roles in nitrogen uptake and assimilation relating to forage and growth characteristics. The BnGS1-2 mRNA levels were remarkably upregulated in the phloem, xylem and stems during the fiber development stage, suggesting a correlation with fiber development. Therefore, the non-overlapping transcript intensity of BnGS genes in different tissues regulates ramie growth and development during different vegetative processes.

Draft genome analysis provides insights into the fiber yield, crude protein biosynthesis, and vegetative growth of domesticated ramie (Boehmeria nivea L. Gaud)

“…Ramie exhibits vigorous vegetative growth, along with a high crude protein content in its tissues. Recently, three N metabolism-related GS genes were identified in ramie, 62 and one of these, BnGS 1 - 2, was overexpressed in transgenic tobacco, which caused significant increases in fresh weight, dry weight, and plant height, along with a higher soluble protein content and higher total N content. 63 Therefore, these previous studies further validated that, in ramie, N metabolism-related genes play important roles in vegetative growth and crude protein biosynthesis.…”

Nitrogen partitioning traits and expression patterns of N metabolism‐associated genes in maize hybrids with contrasting N utilization efficiencies

“…The GS gene expression upon the N fertilizer application has been reported in several monocots. In barley, the GS1 expression was enhanced with the increase of applied N fertilizer (Goodall et al, 2013). While in rice, GS1 expression was varied in response to N fertilizer, showing enhanced levels with N supply increasing in high N-requiring hybrids and declined in low N-requiring hybrids (Gaur et al, 2012).…”

Research Article Large-scale development, characterization, and cross-amplification of EST–SSR markers in Chinese chive

“…However, few SSR markers can have been reported for Chinese chive, mostly owing to the crop's giant genome. Unlike genomic sequencing, transcriptome analysis is rapid, inexpensive, and unaffected by genome size or complexity and, as such, has been widely used as a primary tool for gene discovery (Zheng et al, 2015), investigating crop domestication patterns (Zeng et al, 2016), and gene expression profiling Mei et al, 2016;), especially for the large-scale development of SSR markers (Ding et al, 2015). In the present study, we developed 2533 SSRs using the transcriptome sequence of Chinese chive, and 94% of the makers could successfully amplify their target sequences.…”