3.3 KEGG functional annotation classification and enrichment
analysis of DEPs
The DEPs were also investigated using the KEGG database. Figure 3A
revealed that the DEPs were annotated on five primary metabolic
pathways, including metabolism, genetic information processing,
environmental information processing, cellular process and organismal
systems (Table S5). A large number of proteins were annotated to
pathways such as carbohydrate metabolism, amino acid metabolism,
metabolism of cofactors and vitamins. As can be seen in Figure 3B, in
terms of primary metabolism, proteins were enriched in various amino
acids metabolism including glycine, serine and threonine metabolism and
so on, as well as glycolysis/gluconeogenesis, indicating that the
physiological activity of TH from FXS was vigorous. For the secondary
metabolism, a total of 9 DEPs (6 down-regulated and 3 up-regulated) were
associated with flavonoids biosynthesis with no significant protein
enrichment in pathway. Overall, the quality disparities in TH from
different hosts were primarily caused by DEPs implicated in biosynthetic
pathways of bioactive constituents (Table S6).