## 4 Discussion  
In this study, transcriptome analysis was performed to identify DEGs for PHS-induced and ABA-treated two Korean wheat cultivars with different PHS tolerance. The analysis was focused on the expression patterns of the genes related to hormones metabolism and signaling and differentially expressed genes between treatment and cultivars. In ABA signaling pathway, ABI and AREB/ABF lead the ABA responses and are activated by SnRK2. [PERSON] et al. [32] reported that activities of SnRK2.6 are controlled by ABA and four _SnRK2.6_ (Traces_2_AS_64E0 EF151.1, Traces_2 DL_6 CD064E13.1, Traces_5 AL_4 EE2511 FA.1, and Traces_4 AL_4E99 BA01.1) were identified in our RNA-seq results (Table S9). The degree of up-regulation of SnRK2 and downstream genes _ABIs_ and _AREB/ABFs_ were higher in 'Woori' than 'Keumgang' in both PHS-induced and ABA-treated samples. Figure 3 showed the GA hormone metabolism and the expression patterns of related genes in our RNA-seq data. [PERSON] et al. [33] reported the identification and chromosomal  
Figure 6: Validation of selected DEGs for ABA, GA, IAA, and cytokin by quantitative real-time RT-PCR. location of genes related to GA hormone metabolism in wheat using 'Chinese Spring' null-tetrasomic lines. They isolated three _TaCPS_ genes localized on chromosomes 7A, 7B, and 7D and three _TaKS_ genes localized on chromosomes 2A, 2B, and 2D. DNA gel blotting using _HvCPSL1_ probe showed strong hybridization bands on chromosome group 7 and weak hybridization bands on chromosome group 2 of wheat [34]. Gibberellins have several forms of bio-active and bio-inactive (or precursors) such as GA\({}_{1}\) and GA\({}_{8}\), respectively. In our raw data there were _GA20 ox_ and _GA3 ox_ that convert bio-inactive GA\({}_{19}\) to GA\({}_{20}\) and bio-active GA\({}_{1}\) from bio-inactive GA\({}_{20}\), respectively, but these were not selected in analysis due to the gene selection criteria, unfortunately. _GA20 ox_ was down-regulated in 'Keumgang' (KP and KA) and up-regulated in WA and the contents of GA\({}_{20}\) were lower in 'Keumgang' than 'Woori' (Figure 3). _GA3 ox_ showed no different expression between cultivars except PHS treated samples (higher in KP with RPKM ratio 2.362). After the first identification of GID1 in GA signaling mutants of rice [35], GID1 orthologous were identified in _Arabidopsis_[36; 37]. The ubiquitin-proteasome system (UPS), via SCF complex, is utilized in signaling via many plant hormones, including IAA, jasmonic acid (JA), GA, strigolactone, ethylene, and ABA [38], and SCF complex components were recently studied in developing wheat spikes [33; 39]. Although all the genes encoding GA receptors and SCF complexes were up-regulated, DELLA gene was also up-regulated in 'Woori' (RPKM ratio 4.35 in WP and 4.72 in WA). The other hormones, IAA and cytokinin, are known to regulate seed dormancy and germination via interactions with ABA. IAA interacts with ABA and ABI3. With high IAA content, ARF10/16 is activated and _AB13_ is expressed to maintain seed dormancy [19; 40], and PHS-tolerant cultivar 'Woori' showed up-regulation in all genes encoding ABI3 and ARF10/16, whereas 60% of the genes were up-regulated in 'Keumgang'. [PERSON] et al. [41] proposed that cytokinin regulates germination via interactions between cytokinin signaling and ABA, so that the _Type A ARR_ represses ABI5, promoting germination. Although expression of _Type A ARR_ showed higher up-regulation in 'Woori' than in 'Keumgang,' expression of all three _AB15_ was up-regulated in WP and down-regulated in KP. All the transcriptome analysis results of phytohormone hormone metabolism and signaling suggest that GA, IAA, and cytokinin may play a subordinate role to ABA in terms of dormancy and germination and ABA is the primary regulator of dormancy and inhibition of germination. The DEG analysis also supports the role of ABA in seed dormancy and germination inhibition.