New Insight into Aspartate Metabolic Pathways in Populus: Linking the Root Responsive Isoenzymes with Amino Acid Biosynthesis during Incompatible Interactions of Fusarium solani

Abstract

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.

Genome-Wide Survey and Expression Analyses of Hexokinase Family in Poplar (Populus trichocarpa)

“…HXKs with catalytic activity significantly impact multi-cellular processes and sugar signaling, accounting for the metabolite biosynthesis on the glycolytic pathways, providing energy for cell growth [ 8 ]. During the plant-pathogen interaction, the host defense and immune responses are mounted with a profound modulation of the primary plant metabolism, including biosynthesis of carbohydrates, amino acids, and the derived secondary metabolites [ 60 ].…”

“…The upstream 1.5 kb sequences of gene promotors were predicted by the program PlantCARE. Available online: (accessed on 11 September 2000) to obtain overviews of cis -regulatory elements associated with the responsiveness of biotic and abiotic stresses, according to the previous reports [ 60 ]. The gene structure was deducted by comparing CDS and the corresponding DNA sequence in GSDS.…”

Unraveling the Mechanisms of Efficient Phosphorus Utilization in Popcorn (Zea mays L. var. everta): Insights from Proteomic and Metabolite Analysis

“…The up-regulation of Acyl CoA and ICL in popcorn leaves suggests a conversion of stored lipids into carbohydrates to produce energy-rich molecules in L80 to cope with P deficiency. Additionally, ATT protein increase may be the result of plant adaptation to P deficiency as observed previously in other different environmental conditions in order to improve the energy generation by the TCA cycle and amino acid metabolism. Although photosynthesis and plant growth are also impacted in P7 under low P, the protein abundance of the proteins involved in photosynthesis and energy metabolism is not affected by P deficiency.…”

Editing Metabolism, Sex, and Microbiome: How Can We Help Poplar Resist Pathogens?

“…The content of glutamate, proline, glycine and a number of other amino acids increases, while asparagine levels decrease, as was shown in the same P. trichocarpa-F. solani system. These metabolomic changes occur in accordance with the induction of many genes related to the metabolism of aspartate, probably one of the key players in the amino acid response to infection [135].…”

“…As is well known, breeding involves obtaining resistant genotypes that maintain trait stability over a number of generations, which is a labor-intensive and time-consuming process. For example, instead of increasing the stability of poplars already used in forestry, the adaptation of supposedly more resistant and wild species, such as P. euphratica, discussed above, could be accelerated, just as it is proposed to accelerate the domestication of wild plant forms instead of increasing the stability of domestic varieties [135]. But there is genetic engineering, an effective way to more quickly obtain a variety of source material for further breeding, which undoubtedly reduces the time to obtain a stable plant line.…”