Transcriptome Analysis Reveals Critical Genes and Pathways in Carbon Metabolism and Ribosome Biogenesis in Poplar Fertilized with Glutamine

Abstract

Exogenous Gln as a single N source has been shown to exert similar roles to the inorganic N in poplar ‘Nanlin895′ in terms of growth performance, yet the underlying molecular mechanism remains unclear. Herein, transcriptome analyses of both shoots (L) and roots (R) of poplar ‘Nanlin895’ fertilized with Gln (G) or the inorganic N (control, C) were performed. Compared with the control, 3109 differentially expressed genes (DEGs) and 5071 DEGs were detected in the GL and GR libraries, respectively. In the shoots, Gln treatment resulted in downregulation of a large number of ribosomal genes but significant induction of many starch and sucrose metabolism genes, demonstrating that poplars tend to distribute more energy to sugar metabolism rather than ribosome biosynthesis when fertilized with Gln-N. By contrast, in the roots, most of the DEGs were annotated to carbon metabolism, glycolysis/gluconeogenesis and phenylpropanoid biosynthesis, suggesting that apart from N metabolism, exogenous Gln has an important role in regulating the redistribution of carbon resources and secondary metabolites. Therefore, it can be proposed that the promotion impact of Gln on poplar growth and photosynthesis may result from the improvement of both carbon and N allocation, accompanied by an efficient energy switch for growth and stress responses.

Effects of Date Palm Waste Compost Application on Root Proteome Changes of Barley (Hordeum vulgare L.)

“…The upregulation of β-1,3-1,4-glucanase that degrades mixed linkage glucan, a transient wall polysaccharide found in cereals such as barley, may lead to the increased energy production required for rapid seedling growth [ 40 ]. These results were consistent with several previous investigations [ 23 , 26 , 41 ], who reported that protein hydrolysate, glutamine and humic substances increased the expression of the genes related to carbohydrate metabolism, including glycolysis in various species such as maize, poplar and Arabidopsis, respectively. SnRK1, a central regulator of cellular energy homeostasis, was upregulated, which may lead to the regulation of gene expression associated with carbohydrate metabolism in compost-treated plants, thereby resulting in the control of multiple developmental processes including root cell growth and proliferation [ 42 ].…”

“…It is well known that under stressed conditions, carbohydrates can act as osmoprotectants that remove reactive oxygen species (ROS) and stabilise cellular membranes, which can protect plants from oxidative damage [ 44 ]. Under stressed conditions, several previous studies, such as those on poplar [ 41 ], Arabidopsis [ 23 ], maize [ 45 ] and potato [ 46 ], have shown that the application of biostimulants and organic amendments increases the expression of various proteins that often participate in energy and carbohydrate metabolism. These results suggest that enzymes associated with the glycolytic pathway might assist in the intensification of glycolysis to provide energy for supporting plant growth and metabolic activities under abiotic and biotic stresses.…”

“…Ribosomal proteins (RPs) are not only essential for protein production, but they also play an important role in cell division, growth, proliferation and differentiation, thereby promoting plant growth and development [ 52 ]. Enhanced protein synthesis in biostimulant-treated plant roots such as HS has been previously demonstrated in Arabidopsis roots [ 23 ], poplar roots [ 41 ] and maize roots [ 45 ]. On the other hand, an increase in the abundance of ADC, which catalyses the conversion of arginine (Arg) into agmatine and carbon dioxide [ 53 ] and decreases the abundance of PSP, which is involved in both serine (Ser) and glycine (Gly) biosynthesis [ 54 ], may result in a decrease in the levels of Arg, Ser and Gly in the roots of compost-treated plants.…”

“…This may be due to the fact that, when fertilized with compost, barley-treated plants were inclined to distribute more energy and substances for metabolic processes other than protein synthesis, since ribosome biosynthesis is a process with high energy demand [ 60 ]. This will result in limiting excessive energy input into the ribosome pathway, thereby resulting in more energy, which could be invested in promoting plant growth and development [ 41 ]. Previous studies [ 23 , 61 ] also found that HS can stimulate proteasome complex-related enzymes, such as 26S proteasome non-ATPase regulatory subunit 14 and 26S proteasome non-ATPase regulatory subunit 6 in Arabidopsis and maize roots, respectively.…”

Accelerating Genetic Gain for Key Traits Using Genome-Wide Association Studies and Genomic Selection: Promising Breeding Tools for Sustainable Agriculture

“…At present, it had been reported that OFP was involved in the fruit shape development process of pepper, and CaOVATE was found to be involved in the fruit shape process of tomato through the study of pepper varieties with different fruit shapes (Tsaballa et al, 2011). Expression pattern analysis of Citrus OFPs (CitOFPs) showed that CitOFP19 had significantly higher expression level in the ovaries of round pummelo than in those of pear-shaped pummelo (Wu et al, 2022). We also found that the CazOFP genes were up-regulated in the early stages of pepper fruit development (Dev1~Dev5) in the study.…”