## 2 Results
### Phylogenetic Tree Analysis of Rice Trans-Prenyltransferases
The phylogenetic tree showed that OsSPS2 and 3 in a subgroup A were more closely related to AtGPS1 and 2 (ABF58968 and ABI54337, [PERSON] et al. [18]) and OsSPS1 and 4 in a subgroup B of AtPPS (AAW39025, [PERSON] et al. [17]), suggesting that the families of subgroup A and B are expected to play differential roles as long-chain _trans_-PTs. Moreover, both subgroup A and B are further categorized into monocot and dicot plants and the independent evolution in the plant kingdom is indicated. \begin{table}
\begin{tabular}{l l l l l l l l} \hline \hline
**Groups** & **Names** & **Gene IDs** & **Protein IDs** & \
\begin{tabular}{l} **Size** \\ **(aa)** \\ \end{tabular} &
\begin{tabular}{l} **WoLF** \\ **PSORT * \\ \end{tabular} & **Enzyme Activity** & **Ref.** \\ \hline I\_GPS/GGPS-C & OsGPS & Os01g14630 & BAS71331 & 416 & Chl/Mito & GPP/GGPP & \\ I\_GPS/GGPS-A & OsGGPS1 & Os07g39270 & BAT02334 & 366 & Chl/Mito & GGPP synthase & [10] \\ I\_GPS/GGPS-F & OsGRP & Os02g44780 & XP\_015626863 & 342 & Chl & GGPS-recruiting & [10] \\ II\_SPS/PPS-B & OsSPS1 & Os06g46450 & BAS99121 & 430 & Mito/Chl & SPP/PP synthase & [20] \\ II\_SPS/PPS-A & OsSPS2 & Os05g5050 & Q75 HZ9 & 403 & Chl/Mito & SPP synthase & [20] \\ II\_SPS/PPS-A & OsSPS3 & Os12g17320 & XP\_015620200 & 414 & Chl/Mito & SPP synthase & [21] \\ II\_SPS/PPS-B & OsSPS4 & Os08g09370 & XP\_015648843 & 399 & Chl/Mito & The predicted-PPP & - \\ III\_FPS-B & OsFS1 & Os01g50760 & BAS73911 & 353 & Cyto & The predicted-FPP & [22] \\ III\_FPS-B & OsFS2 & Os05g46580 & BAS95151 & 355 & Cyto & The predicted-FPP & [24] \\ III\_FPS-B & OsFS3 & Os01g50050 & XP\_015621770 & 356 & Cyto/Nuc & The predicted-FPP & - \\ III\_FPS-A & OsFS4 & Os04g56230 & MT793647 & 354 & Cyto & The predicted-FPP & - \\ III\_FPS-A & OsFS5 & Os04g56210 & BAS91413 & 392 & Cyto/Nuc & The predicted-FPP & - \\ \hline \hline \end{tabular}  
* \({}^{2}\), WoLF PSPORT: [[https://wolfpsort.hgc.jp/](https://wolfpsort.hgc.jp/)]([https://wolfpsort.hgc.jp/](https://wolfpsort.hgc.jp/)); Chl, chloroplast; Cyto, cytosol; Mito, mitochondria; Nuc, nucleous.  
\end{table} 
Table 1: The summarized molecular information of rice _trans_-premyltransferases (PTs). In Group III, as the FPS family, five rice PTs were identified and designated according to sequence similarity, with _Arabidopsis_ FPS1 (AAL34286, [PERSON] et al. [28]), a known OsFPS1 (70.5%, [PERSON] et al. [22]) and four new rice FPS genes in this study: OsFPS2 (66.5%), OsFPS3 (62.4%), OsFPS4 (52.5%), OsFPS5 (50.1%) (Figure 1 and Table 1). Among three subgroups of A, B and C in Group III, none of the dicot FPS were classified in the subgroups of A or B, and none of monocot FPS were observed in subgroup A, showing evolutionary dissociation between monocot and dicot plants for the adaptation to environmental conditions. Rice FPSs belonged to two subgroups: OsFPS4 and 5 in subgroup A and OsFPS1 to 3 in subgroup B. Interestingly, wheat (_Triticum aestivum_) FPSs [29] are classified into both subgroups, like rice, but all of maize FPSs [30] belong to a subgroup B, unlike rice. Taken together, rice has evolved to have a high copy number of FPS family genes, as there are five, compared to two copies reported in _Arabidopsis_. Subgroup A genes including OsFPS4 and 5 may have evolved to have some unique roles in several monocot plants including rice, barley (_Hordeum vulgare_), sorghum (_Sorghum bicolor_) and wheat, compared to other plant FPS subgroups.