Carbon and nitrogen metabolism affects kentucky bluegrass rhizome expansion

Abstract

Background Rhizome is vital for carbon and nitrogen metabolism of the whole plant. However, the effect of carbon and nitrogen in the rhizome on rhizome expansion remains unclear. Results Three wild Kentucky bluegrass (Poa pratensis L.) germplasms with different rhizome expansion capacity (strong expansion capacity, ‘YZ’; medium expansion capacity, ‘WY’; and weak expansion capacity, ‘AD’) were planted in the field and the rhizomes number, tiller number, rhizome dry weight, physiological indicators and enzyme activity associated carbon and nitrogen metabolisms were measured. Liquid chromatography coupled to mass spectrometry (LC-MS) was utilized to analyze the metabolomic of the rhizomes. The results showed that the rhizome and tiller numbers of the YZ were 3.26 and 2.69-fold of that of the AD, respectively. The aboveground dry weight of the YZ was the greatest among all three germplasms. Contents of soluble sugar, starch, sucrose, NO3−-N, and free amino acid were significantly higher in rhizomes of the YZ than those of the WY and AD (P < 0.05). The activities of glutamine synthetase (GS), glutamate dehydrogenase (GDH) and sucrose phosphate synthase (SPS) of the YZ were the highest among all three germplasm, with values of 17.73 A·g− 1 h− 1, 5.96 µmol·g− 1 min− 1, and 11.35 mg·g− 1 h− 1, respectively. Metabolomics analyses revealed that a total of 28 differentially expressed metabolites (DEMs) were up-regulated, and 25 DEMs were down-regulated in both comparison groups (AD vs. YZ group and WY vs. YZ group). Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analysis demonstrated that metabolites related to histidine metabolism, tyrosine metabolism, tryptophan metabolism, and phenylalanine metabolism were associated with rhizomes carbon and nitrogen metabolism. Conclusions Overall, the results suggest that soluble sugar, starch, sucrose, NO3−-N, and free amino acid in rhizome are important to and promote rhizome expansion in Kentucky bluegrass, while tryptamine, 3-methylhistidine, 3-indoleacetonitrile, indole, and histamine may be key metabolites in promoting carbon and nitrogen metabolism of rhizome.

Exogenous GR24 Inhibits Strawberry Tillering by Affecting the Phytohormone Signaling and Sugar Metabolism Pathways

“…In other plant species, such as creeping bentgrass (Agrostis stolonifera L.), an elevated carbon dioxide (CO 2 ) concentration promotes stolon growth and increases the accumulation of glucose, sucrose, fructose, and endogenous IAA at the stolon nodes and internodes, resulting in longer stolons and larger stolon shoot biomass [11]. Kentucky bluegrass (Poa pratensis L.) with more ramets also exhibits a significant increase in the soluble sugar content in the rhizome [12]. In addition, studies on strawberries have revealed that auxin and CTK play antagonistic roles in controlling the development of axillary buds.…”