Genomics and Applied Biology 2024, Vol.15, No.2, 75-88 http://bioscipublisher.com/index.php/gab 83 7 Functional Genomics and Metabolic Pathways 7.1 Key metabolic pathways inE. ulmoides E. ulmoides, a tree species known for its medicinal and industrial applications, exhibits several key metabolic pathways that are crucial for its unique properties. One of the primary pathways is the methylerythritol-phosphate (MEP) pathway, which is responsible for rubber biosynthesis. Unlike Hevea brasiliensis, which uses the mevalonate pathway, E. ulmoides predominantly utilizes the MEP pathway to synthesize isoprenyl diphosphate, a precursor for trans-polyisoprene found in its leaves and central peels (Figure 3) (Li et al., 2020). Additionally, the glycolytic pathway in E. ulmoides kernels provides cellular energy and intermediates for other biosynthetic processes, playing a significant role in the accumulation of α-linolenic acid (ALA) (Feng et al., 2016). The chlorogenic acid (CGA) biosynthesis pathway is another critical metabolic route, with enzymes preferentially expressed in the leaves (Ye et al., 2019; Li et al., 2020). Figure 3 The E. ulmoides rubber biosynthesis pathway and expression profiles of genes involved in the pathway (Adopted From Li et. al., 2020) Imagine Caption (Adopted From Li et. al., 2020): The expression level is presented by log2-transformed fragments mapped per kilobase of transcript length per million total mapped reads (log2-FPKM). ACAT acetyl-coenzyme A (CoA) C-acetyltransferase; HMGS hydroxymethylglutaryl-CoA synthase; HMGR hydroxymethylglutaryl-CoA reductase; MVK mevalonate kinase; PMK 5-phosphomevalonate kinase; MPD mevalonate pyrophosphate decarboxylase; DXS 1-deoxy-d-xylulose 5-phosphate synthase; DXR 1-deoxy-d-xylulose 5-phosphate reductoisomerase; MCT 2-C-methyl-d-erythritol 4-phosphate cytidylyltransferase; CMK 4-(cytidine 5′-diphospho)-2-C-methyl-d-erythritol kinase; MDS 2-C-methyl-d-erythritol 2,4-cyclodiphosphate synthase; HDS 4-hydroxy-3-methylbut-2-enyl diphosphate synthase; HDR 4-hydroxy-3-methylbut-2-enyl diphosphate reductase; IDI isopentenyl diphosphate isomerase; GPS geranyl diphosphate synthase; FPS farnesyl diphosphate synthase; GGPS, geranylgeranyl diphosphate synthase; SRPP small rubber particle protein; Acetyl-CoA acetyl coenzyme-A; Acetoacetyl-CoA, 3-acetoacetyl-CoA; HMG-CoA, 3-hydroxy-3-methylglutaryl-CoA; MVA mevalonate; MVA-5P mevalonate-5-phosphate; MVA-5PP mevalonate-5-diphosphate; GA-3-P, glyceraldehyde 3-phosphate; DXP, 1-deoxy-d-xylulose 5-phosphate; MEP 2-C-methyl-d-erythritol 4-phosphate; CME 4-(cytidine 5′-diphospho)-2-C-methyl-d-erythritol; PCME 2-phospho-4-(cytidine 5′-diphospho)-2-C-methyl-d-erythritol; CMEC 2-C-methyl-d-erythritol 2,4-cyclodiphosphate; HMED 4-hydroxy-3-methylbut-2-enyl diphosphate; IPP isopentenyl diphosphate; DMAPP, dimethylallyl diphosphate; GPP geranyl diphosphate; FPP farnesyl diphosphate; GGPP, geranylgeranyl diphosphate. LF leaf; CP central peel; PE peel edge; XM xylem; SD seed
RkJQdWJsaXNoZXIy MjQ4ODYzMg==