Figure 5 - available via license: CC BY
Content may be subject to copyright.
Relative expression levels of PnAS1 (A), PnAS2 (B), and PnAS3 (C) under continuous light/dark conditions. The control (CK) reflects expression under a normal photoperiod.

Relative expression levels of PnAS1 (A), PnAS2 (B), and PnAS3 (C) under continuous light/dark conditions. The control (CK) reflects expression under a normal photoperiod.

Source publication
Article
Full-text available
Asparagine synthetase (AS), a key enzyme in plant nitrogen metabolism, plays an important role in plant nitrogen assimilation and distribution. Asparagine (Asn), the product of asparagine synthetase, is one of the main compounds responsible for organic nitrogen transport and storage in plants. In this study, we performed complementation experiments...

Contexts in source publication

Context 1
... expression levels were low in leaves from the three different positions and were apparently unaffected by diurnal rhythm, consistent with the weak expression of PnAS3 observed in shoots. At the transcriptional level, the three genes exhibited significant changes under continuous light or dark treatments ( Figure 5). In the case of continuous light, the expression levels of PnAS1 at the three different leaf positions were not significantly different from that under a normal photoperiod, but increased significantly under dark treatment. ...
Context 2
... previous studies have shown that exogenous light and sucrose can cause changes in the expression levels of AS1 and AS2 [16,20], we examined changes in expression patterns of genes such as PnAS1 and PnAS2 under long-term light and dark conditions. We observed that PnAS1 and PnAS3 expressions were significantly increased under dark conditions, whilePnAS2 expression significantly increased only in L1 leaves under dark conditions ( Figure 5). Asparagine and glutamine are the two major nitrogen transport compounds in plants [34,35]. ...

Citations

... Besides, targeting Asn acquisition and utilization has been proved beneficial in various pre-clinical models, shedding light on a broader cancer therapeutic strategy [66]. In Populus, three putative AS isoenzymes were functionally characterized using the complementation assay that corroborates our work [67]. Nevertheless, regarding Asn metabolism and stress regulation, the in vivo roles of the AS encoding genes have not been elucidated in Populus. ...
Article
Full-text available
Integrating amino acid metabolic pathways into plant defense and immune systems provides the building block for stress acclimation and host-pathogen interactions. Recent progress in L-aspartate (Asp) and its deployed metabolic pathways highlighted profound roles in plant growth and defense modulation. Nevertheless, much remains unknown concerning the multiple isoenzyme families involved in Asp metabolic pathways in Populus trichocarpa, a model tree species. Here, we present comprehensive features of 11 critical isoenzyme families, representing biological significance in plant development and stress adaptation. The in silico prediction of the molecular and genetic patterns, including phylogenies, genomic structures, and chromosomal distribution, identify 44 putative isoenzymes in the Populus genome. Inspection of the tissue-specific expression demonstrated that approximately 26 isogenes were expressed, predominantly in roots. Based on the transcriptomic atlas in time-course experiments, the dynamic changes of the genes transcript were explored in Populus roots challenged with soil-borne pathogenic Fusarium solani (Fs). Quantitative expression evaluation prompted 12 isoenzyme genes (PtGS2/6, PtGOGAT2/3, PtAspAT2/5/10, PtAS2, PtAspg2, PtAlaAT1, PtAK1, and PtAlaAT4) to show significant induction responding to the Fs infection. Using high-performance liquid chromatography (HPLC) and non-target metabolomics assay, the concurrent perturbation on levels of Asp-related metabolites led to findings of free amino acids and derivatives (e.g., Glutamate, Asp, Asparagine, Alanine, Proline, and α-/γ-aminobutyric acid), showing marked differences. The multi-omics integration of the responsive isoenzymes and differential amino acids examined facilitates Asp as a cross-talk mediator involved in metabolite biosynthesis and defense regulation. Our research provides theoretical clues for the in-depth unveiling of the defense mechanisms underlying the synergistic effect of fine-tuned Asp pathway enzymes and the linked metabolite flux in Populus.
... Asparagine synthetase (ASN) is an aminotransferase determined by a small and simple gene family that is broadly found in plants [50]. ASN uses ammonium and glutamine to form asparagine, which plays a key role in N transport and metabolism in plants [4,50]. ...
... Asparagine synthetase (ASN) is an aminotransferase determined by a small and simple gene family that is broadly found in plants [50]. ASN uses ammonium and glutamine to form asparagine, which plays a key role in N transport and metabolism in plants [4,50]. Asparagine is well known for N transport and storage that is produced from glutamine amide group and aspartate in the presence of ASN [33]. ...
Article
Full-text available
Asparagine synthetase (ASN) is one of the key enzymes of nitrogen (N) metabolism in plants. The product of ASN is asparagine, which is one of the key compounds involved in N transport and storage in plants. Complete genome-wide analysis and classifications of the ASN gene family have recently been reported in different plants. However, little is known about the systematic analysis and expression profiling of ASN proteins in cotton development and N metabolism. Here, various bioinformatics analysis was performed to identify ASN gene family in cotton. In the cotton genome, forty-three proteins were found that determined ASN genes, comprising of 20 genes in Gossypium hirsutum (Gh), 13 genes in Gossypium arboreum, and 10 genes in Gossypium raimondii. The ASN encoded genes unequally distributed on various chromosomes with conserved glutamine amidotransferases and ASN domains. Expression analysis indicated that the majority of GhASNs were upregulated in vegetative and reproductive organs, fiber development , and N metabolism. Overall, the results provide proof of the possible role of the ASN genes in improving cotton growth, fiber development, and especially N metabolism in cotton. The identified hub genes will help to functionally elucidate the ASN genes in cotton development and N metabolism.
... Thus, AS is regarded as a key enzyme that participates in nitrogen assimilation. In plants, only asparagine synthetase-B (AS-B) is found, and it can be subdivided into two classes in accordance with its expression under light Qu et al., 2019). Previous studies showed that nitrogen, as one of the basic plant metabolisms, is involved in plant-pathogen interactions (Delledonne et al., 2001;Qiao & Fan, 2008;Wendehenne et al., 2001). ...
Article
Full-text available
Asparagine synthetase is a key enzyme that catalyses the conversion of amide groups from glutamine or ammonium to aspartate, which leads to the generation of aspara-gine. However, the role of asparagine synthetase in plant immunity remains largely unknown. Here, we identified a Nicotiana benthamiana asparagine synthetase B (NbAS-B) that associates with tomato mosaic virus coat protein-interacting protein L (IP-L) using the yeast two-hybrid assay and examined its role in tobacco mosaic virus (TMV) resistance. The association of IP-L with NbAS-B was further confirmed by in vivo co-immunoprecipitation, luciferase complementation imaging, and bimolecular fluorescence complementation assays. IP-L and NbAS-B interact in the nucleus and cytosol and IP-L apparently stabilizes NbAS-B, thus enhancing its accumulation. The expressions of IP-L and NbAS-B are continuously induced on TMV-green fluorescent protein (GFP) infection. Co-silencing of IP-L and NbAS-B facilitates TMV-GFP infection. Overexpression of NbAS-B in tobacco reduces TMV-GFP infection by significantly improving the synthesis of asparagine. Furthermore, the external application of asparagine significantly inhibits the infection of TMV-GFP by activating the sali-cylic acid signaling pathway. These findings hold the potential for the future application of asparagine in the control of TMV.
... Asparagine is a fundamental amino acid for nitrogen storage and transport in plants (Canales et al. 2012). This amino acid is synthesized from glutamine and aspartate by an ATP-dependent reaction, which is catalyzed by asparagine synthase (Xu et al. 2012, Qu et al. 2019. In this context, asparagine synthetase is a key enzyme in plant nitrogen metabolism, and has an important role in nitrogen distribution and assimilation (Qu et al. 2019). ...
... This amino acid is synthesized from glutamine and aspartate by an ATP-dependent reaction, which is catalyzed by asparagine synthase (Xu et al. 2012, Qu et al. 2019. In this context, asparagine synthetase is a key enzyme in plant nitrogen metabolism, and has an important role in nitrogen distribution and assimilation (Qu et al. 2019). ...
Article
Full-text available
Natural variation of cyanogenic glycosides, soluble sugars, proline and nondestructive optical sensing of pigments (chlorophyll, flavonols and anthocyanins) were examined in ex situ natural populations of Eucalyptus cladocalyx F. Muell. grown under dry environmental conditions in the southern Atacama Desert, in Chile. After 18 consecutive dry seasons, considerable plant‐to‐plant phenotypic variation for all the traits was observed in the field. For example, leaf hydrogen cyanide (HCN) concentrations varied from 0 (two acyanogenic individuals) to 1.54 mg cyanide g–1 dry weight. Subsequent genome‐wide association study (GWAS) revealed associations with several genes with a known function in plants. HCN content was associated robustly with genes encoding Cytochrome P450 proteins, and with genes involved in the detoxification mechanism of HCN in cells (β‐cyanoalanine synthase and cyanoalanine nitrilase). Another important finding was that sugars, proline and pigment content were linked to genes involved in transport, biosynthesis and/or catabolism. Estimates of genomic heritability (based on haplotypes) ranged between 0.46 and 0.84 (HCN and proline content, respectively). Proline and soluble sugars had the highest predictive ability of genomic prediction models (PA = 0.65 and PA = 0.71, respectively). PA values for HCN content and flavonols were relatively moderate, with estimates ranging from 0.44 to 0.50. These findings provide new understanding on the genetic architecture of cyanogenic capacity, and other key complex traits in cyanogenic E. cladocalyx. This article is protected by copyright. All rights reserved.
... Such upregulation in response to diverse types of stress has been observed, for example, in sunflower (Helianthus annuus) (Herrera- Rodriguez et al. 2007), Arabidopsis (Arabidopsis thaliana) (Lam et al. 1998;Baena-González et al. 2007), maize (Zea mays) (Chevalier et al. 1996), and wheat (Triticum aestivum) (Curtis et al. 2019;Wang et al. 2005). Upregulation has also been observed in soybean (Glycine max) (Antunes et al. 2008 (Qu et al. 2019), and common bean (Phaseolus vulgaris) (Osuna et al. 2001) in response to nitrogen. This implies that the asparagine that accumulates during stress is synthesised predominantly de novo and not just as a result of proteolysis and amino acid catabolism. ...
Article
Full-text available
Plant stress and poor crop management strategies compromise the foundations of food security: crop yield, nutritional quality and food safety. Accumulation of high concentrations of the amino acid asparagine in its free (soluble, non-protein) form is an example of an undesirable outcome of stress for the nutritional quality and food safety of wheat because of its role as a precursor to acrylamide, a carcinogenic processing contaminant. In this review, we cover what is known about the mechanisms and functions of free asparagine accumulation in the grain during normal development and particularly during stress in wheat. Comparisons with other plant species, yeast, and mammals are drawn in order to gain deeper insight into the conserved biology underlying asparagine accumulation. Crop management strategies and practices are discussed in the context of managing asparagine accumulation, which must be balanced against other desirable goals, such as sustainability, protein content and yield.
... After the final cycle, a melting curve analysis was performed over a temperature range of 55-95°C in increments of 1°C to verify the reaction specificity. Using the actin gene [37] as a constitutive reference, relative expression was measured by the 2 − ΔΔ Ct method [38]. The primers used in this study are given in Additional file 1: Table S4. ...
Article
Full-text available
Background: Seed germination, the foundation of plant propagation, involves a series of changes at the molecular level. Poplar is a model woody plant, but the molecular events occurring during seed germination in this species are unclear. Results: In this study, we investigated changes in gene transcriptional levels during different germination periods in poplar by high-throughput sequencing technology. Analysis of genes expressed at specific germination stages indicated that these genes are distributed in many metabolic pathways. Enrichment analysis of significantly differentially expressed genes based on hypergeometric testing revealed that multiple pathways, such as pathways related to glycolysis, lipid, amino acid, protein and ATP synthesis metabolism, changed significantly at the transcriptional level during seed germination. A comparison of ΣZ values uncovered a series of transcriptional changes in biological processes related to primary metabolism during poplar seed germination. Among these changes, genes related to CHO metabolism were the first to be activated, with subsequent expression of genes involved in lipid metabolism and then those associated with protein metabolism. The pattern of metabolomic and physiological index changes further verified the sequence of some biological events. Conclusions: Our study revealed molecular events occurring at the transcriptional level during seed germination and determined their order. These events were further verified by patterns of changes of metabolites and physiological indexes. Our findings lay a foundation for the elucidation of the molecular mechanisms responsible for poplar seed germination.
Article
Pakchoi (Brassica campestris L. ssp. chinensis) is an important leafy vegetable. Various light spectra, especially red and blue light, play vital roles in the regulation of nitrate metabolism. Information on the effects of red and blue light on nitrate metabolism at the transcriptome level in pakchoi is still limited, so this study used RNA sequencing technology to explore this molecular mechanism. Through pairwise comparisons with white LED light, 3 939 and 5 534 differentially expressed genes (DEGs) were identified under red and blue light, respectively. By Kyoto Encyclopedia of Genes and Genomes (KEGG) and Gene Ontology (GO) analyses, these unigenes were found to be involved in nitrate assimilation, plant–pathogen interaction, biosynthesis of secondary metabolites, and phenylpropanoid biosynthesis. The differential effects of light spectra on the nitrate concentration and metabolism-related enzyme activities were also confirmed at the physiological level. Several signal transduction modules, including Crys/Phys-COP1-HY5/HY5-like, were found to be involved in red and blue light-induced nitrate metabolism, and the transcript levels for this complex were consistent with the observed degree of nitrate assimilation. The expression patterns of 15 randomly selected DEGs were further validated using qPCR. Taken together, the results of this study could help improve our understanding of light spectrum-regulated nitrate metabolism in pakchoi at the transcriptome level.
Article
Plant Pectin acetylesterase (PAE) belongs to family CE13 of carbohydrate esterases in the CAZy database. The ability of PAE to regulate the degree of acetylation of pectin, an important polysaccharide in the cell wall, affects the structure of plant cell wall. In this study, ten PtPAE genes were identified and characterized in Populus trichocarpa genome using bioinformatics methods, and the physiochemical properties such as molecular weight, isoelectric points, and hydrophilicity, as well as the secondary and tertiary structure of the protein were predicted. According to phylogenetic analysis, ten PtPAEs can be divided into three evolutionary clades, each of which had similar gene structure and motifs. Tissue-specific expression profiles indicated that the PtPAEs had different expression patterns. Real-time quantitative PCR (RT-qPCR) analysis showed that transcription level of PtPAEs was regulated by different CO2 and nitrogen concentrations. These results provide important information for the study of the phylogenetic relationship and function of PtPAEs in Populus trichocarpa. Supplementary information: The online version contains supplementary material available at 10.1007/s13205-021-02918-1.
Article
Basal stem rot (BSR) disease caused by Ganoderma boninense has remained as one of the major obstacles in oil palm (Elaeis guineensis Jacq.) plantation. BSR is a destructive disease, which contributes to significant yield losses and impacts to the oil palm industry. However, to date, there is still no effective control of the disease. Metabolite fingerprinting is an established non-targeted screening approach to classify samples based on metabolite patterns that change in response to G. boninense infection in oil palm. This study aimed to compare the metabolic profiles of natural Ganoderma-infected and healthy control oil palm root samples using liquid chromatography-quadrupole/time-of-flight-mass spectrometry (LC-Q/TOF-MS) combined with multivariate data analysis (MVDA) and to identify potential metabolic pathway(s) involved in response to BSR. MVDA revealed differential metabolites from oil palm root associated with natural Ganoderma-infected vs. healthy oil palms. A systematic metabolic pathway analysis of differential metabolites discovered the significant involvement of amino acid metabolism, carbohydrate metabolism and biosynthesis of other secondary metabolites in response to BSR disease. Unravelling the metabolic mechanisms involved during pathogen attack provides new knowledge and fill gaps in the information related to the oil palm-Ganoderma pathosystem.
Article
Plant UDP-glucose 6-dehydrogenase (UGDH) is an important enzyme for the formation of hemicellulose and pectin. Previous studies on UGDH have primarily focused on the biosynthesis of cell wall polysaccharides, while few studies have focused on their regulation by exogenous nitrogen. In the present study, four genes encoding PtUGDH proteins were analyzed by bioinformatics methods. And, the expression profiles of PtUGDH genes under different nitrogen treatments were evaluated with qRT-PCR. The results showed that PtUGDHs have conserved NAD coenzyme binding motif GAGYVGG and the catalytic motif GFGGSCFQKDIL. According to the phylogenetic analysis, PtUGDHs were divided into two subgroups. PtUGDH3 and PtUGDH4 were closely related to AtUGDH1 (important for normal development of Arabidopsis cell wall structure). Chromosomal distribution and genome synteny analysis revealed four segmental-duplicated gene pairs on chr4, 8, 10 and 17. Tissue-specific data from PlantGenIE showed that PtUGDH3 and PtUGDH4 were highly expressed in stems. The qRT-PCR detection showed that the expression of PtUGDH3 in the lower stem and PtUGDH2 of upper leaves were significantly increased induced by low ammonium or nitrate condition. This comprehensive analysis of the UGDH family in poplar provides new insights into their regulation by nitrogen, and would increase our understanding of the roles of UGDHs in hemicellulose and pectin biosynthesis in the cell wall and during poplar development. Supplementary information: The online version contains supplementary material available at 10.1007/s13205-021-02697-9.