2.7. Gene Ontology (GO), Eukaryotic Orthologous Groups (KOG) and Kyoto Encyclopedia of Genes and Genomes (KEGG) Analysis

For Gene Ontology (GO) analysis, UniProtKB IDs were used to obtain GO annotation, and functional classification was done using the online tool, ‘Panther classification system’ (Panther15.0, 21 February 2020; pantherdb.org/geneListAnalysis.do (accessed on 3 June 2020).

For functional analysis, we converted the gene names to UniProtKB IDs and subsequently converted to FASTA files by Uniprot, uniprot.org (accessed on 3 June 2020) and then submitted to EggNOG-mapper (EggNOG v5.0; eggnog-mapper.embl.de (accessed on 5 June 2020)) to obtain the Eukaryotic Orthologous Groups (KOG) annotations of differentially expressed genes. The KOG analysis was performed to classify the identified genes into four comprehensive classes: metabolism, cellular process and signaling, information storage and processing, and poorly characterized [37].

For Kyoto Encyclopedia of Genes and Genomes (KEGG) analysis, the FASTA files were uploaded to an online server, ‘KAAS–KEGG Automatic Annotation Server’ (genome.jp/kegg/kaas (accessed on 8 June 2020)) to obtain KEGG Orthology (KO) IDs. The KO IDs were then submitted to the KEGG mapper web server, http://www.genome.jp/kegg/tool/map_pathway2.html (accessed on 10 June 2020) for pathway analyses.