Figure 4.

Analysis of specific prenyltransferase genes for biosynthesis of prenylated flavonoids. (A) Biosynthetic pathways of prenylated flavonoids in E. pubescens. (B) Phylogenetic tree of prenyltransferase genes (PTs). Clades of PTs were classified by their respective substrates, including two categories, flavonoid/polyphenol and others labeled with coral color and light blue color respectively; 11 candidate flavonoid PTs from E pubescens were marked with blue star and EpPT8 was highlighted with red color. (C) Expression profiles of 19 putative E. pubescens prenyltransferase genes (EpPTs) in different tissues. Expression levels in the heatmap were scaled from blue to red (low to high); protein IDs were labeled on the right of heatmap; different tissue samples were labeled at the bottom. (D) Verification of the products from the reaction catalyzed by recombinant EpPT8 protein using kaempferol as substrate. The reaction catalyzed by EpPT8 was illustrated on the top part of the panel; at the bottom part of the panel, HPLC chromatographs at 254 nm from the examined standards and different reaction mixes were colored with gold, green, blue and red color, representing Kaempferol standard, 8-prenylkaempferol standard, the reaction mix of Kaempferol+vector and the reaction mix of Kaempferol+EpPT8 respectively; the peaks of Kaempferol and 8-prenylkaempferol were pointed out on the first chromatograph with black arrows separately and the corresponding peaks of other three chromatographs were indicated through black dotted line.