*2.5. DEGs in Anthocyanin Biosynthesis and MBW Genes*

There were 10 DEGs in flavonoid biosynthesis which are directly related to spot pattern, including *PeANS* (PEQU\_25924), *PeF3 H* (PEQU\_00400), *PeC4H* (PEQU\_12025), *PeDFR* (PEQU\_34933), *PeCHI* (PEQU\_22606), *PeF3H1* (PEQU\_38891), *PeF3H* (PEQU\_22432), *PePAL* (PEQU\_01877), *Pe4CL2* (PEQU\_00756), Pe4CL (PEQU\_07458), and most of them presented higher expression level in spot areas than non-spot areas (Table 1, Figure 4).

**Table 1.** Putative anthocyanin structural genes identified from differentially expressed genes (DEGs).


**Figure 4.** Heatmap of differentially expressed structure genes (DEGs) related to anthocyanin biosynthesis in *Phalaenopsis*. Bold arrow means up/downregulations of genes. (PAL, phenylalanine ammonia lyase; C4H, cinnamate-4-hydroxylase; 4CL, 4-coumarate–CoA ligase; CHS, chalcone synthase; CHI, chalcone isomerase; F3H, flavanone 3-hydroxylase; F3 H, Flavonoid 3'-hydroxylase; DFR, dihydroflavonol 4-reductase; ANS, Anthocyanidin synthase; DHK, dihydrokaempferol; DHQ, dihydroquercetin; DHM, dihydromyricetin; LC, leucocyanidin; Cy, cyaniding).

As for the MBW transcriptor genes related to the anthocyanin synthesis, 4 unigenes were found having significant expression difference including 3 MYB uingenes and 1 bHLH unigene (Table 2). In these transcriptor unigenes, 2 MYB unigenes and 1 bHLH unigene were upregulated and 1 MYB unigene was downregulated.


**Table 2.** Putative MBW genes identified from differentially expressed genes (DEGs).
