## 3 Results
### Gene Ontology (GO) Network Analysis of DEGs  
To identify the genes that interacted with phytohormones metabolisms or signaling, the DEGs were divided into 8 groups based on their comparative expression levels. DEGs included in phytohormone metabolisms and signaling pathways were excluded for the GO analysis. The comparative expression levels and number of DEGs are illustrated in Table 2.  
Group-I to group-IV represents the DEGs that showed higher expression in 'Woori' compared to 'Keumgang', and group-V to group-VIII represents the DEGs that showed higher expression in 'Keumgang' compared to 'Woori'. Group-I, II, V, and VI represents the DEGs that showed higher expression in ABA treatment, including the genes with differential expression between PHS treatment (group-I and V), or including the genes that are not the DEGs (group-II and VI). As we are interested in the DEGs expressed in the PHS tolerant cultivar, 'Woori', the DEGs that were known to interact with phytohormones were screened in the group-I to IV. GO analysis of group-V to VIII are represented in Figure S1 and Tables S5-S8.  
To understand the biological relevance of the DEGs of each analysis groups, we performed functional enrichment analysis using ClueGO with ontology sources of cellular component (CC), biological process (BP), and molecular function (MF). Among 456 DEGs included in group-I, 230 genes were matched to _Arabidopsis_ orthologous and were mainly involved in the flavonoid biosynthetic process, benzene-containing compound metabolic process, and alpha-amino acid catabolic process (Figure 1A, Table S1). Group-II have DEGs of four categories of L-phenylalanine metabolic processes, sugar:proton symporter activity, drug transmembrane transport, and positive regulation of translation (Figure 1B, Table S2). In group-III, 85 _Arabidopsis_ orthologous were identified and functionally categorized. A total of 30 GO terms were categorized into 12 functional groups including filiform apparatus and trehalose biosynthetic processes (Figure 1C, Table S3). Group-IV has 7 categories including the trehalose biosynthetic process, potassium/proton antiporter activity, and GMP synthase (glutamine-hydrolyzing) activity (Figure 1D, Table S4). Group-V has 10 categories including cysteine-type peptidase activity, cytoplasmic side of plasma membrane, and DNA conformation change (Figure S1A, Table S5). Group-VI DEGs, which showed comparatively higher expression in 'Keumgang' under ABA-treatment but showed no significantly different expression between two cultivars under PHS-induction, were divided into 5 categories (nucleosome, regulation of anthocyanin metabolic process, cellulose biosynthetic process, GA mediated signaling pathway, and regulation of ABA-activated signaling pathway) (Figure S1B, Table S6). Among 428 DEGs included in group-VII, 308 genes were matched to _Arabidopsis_ orthologous (TAIR gene IDs) and were mainly involved in chloroplast thylakoid, including photosynthetic processes (Figure S1C, Table S7). In group-VIII, there were 32 _Arabidopsis_ orthologous genes among 43 DEGs divided into 7 functional categories including abscisic aldehyde oxidase activity, linoleic 9S-lipoxygenase activity, and the chitin catabolic process (Figure S1D, Table S8).  
\begin{table}
\begin{tabular}{c c c} \hline \hline
**Group** & **Comparative Expression** & **Number of DEGs** \\ \hline I & WA \(>\) KA & 456 \\ II & KP = WP, WA \(>\) KA & 135 \\ III & WP \(>\) KP & 153 \\ IV & KA = WA, WP \(>\) KP & 62 \\ V & KA \(>\) WA & 449 \\ VI & KP = WP, KA \(>\) WA & 136 \\ VII & KP \(>\) WP & 428 \\ VIII & KA = WA, KP \(>\) WP & 42 \\ \hline \hline \end{tabular}
\end{table}
Table 2: Grouping comparative expression levels and number of differentially expressed genes (DEGs).