## 2 Results
### Analyses of Gene Expressions in Hop Cones of Healthy and HVLd-Infected Plants
\begin{table}
\begin{tabular}{c c c} \hline
**Abbrev.** & **Gene** & **Number*** \\ \hline \multicolumn{3}{c}{Bitter acids biosynthesis} \\ \cline{2-3} BCAT1 & Branched-chain amino acid aminotransferase 1 & 002627F.g2, JQ063073 \\ VPS & Phloriosovalerophenone synthase & 001329F.g74, FJ554588 \\ PT1L & 2-acylphloroglucylation 4-phenyltransferase & KM222441 \\ PT2 & 2-acyl-4-phenylphogluculation 6-phenyltransferase & KM222442 \\ HS1 & Monooxygenase 2 (Humulone synthase 1) & 010625F.g1, 008956F.g7, KJ398144 \\ HS2 & Monooxygenase 2 (Humulone synthase 2) & 008118F.g14, KJ398145 \\  & Polyphenols and flavonoids biosynthesis & \\ \multicolumn{3}{c}{Flavonoids biosynthesis} \\ \cline{2-3} PAL & Phenylalanine ammonia-lyase & 000198F.g108, g113, g114, g115, g116, g117 \\
4 CL2 & 4-coumarate-CoA ligase 2 & 001395F.g25 \\ CHSH1 & Naringenin-chalcone synthase (CHS\_H1) & 000203F.g58, AJ304877 \\ OMT1 & O-methyltransferasefaserase 1 (Desmethylxanthhoumol & 000009F.g116, EU309725 \\
6’-O-methyltransferasefaserase) & 001909F.g33 \\ F3H & Flavanone 3-hydroxylase & 001909F.g33 \\ LAR & Leucanthocyanidin reductase & 000109F.g58, HQ734722 \\ \multicolumn{3}{c}{Terpenes biosynthesis} \\ \cline{2-3} GPPS-SSU & Geranyl diphosphate synthase small subunit & 001483F.g7, FJ455406 \\ FPPS & Farnesely pyrophosphate synthase & 000817F.g23, AB053487, AF268889 \\ MTS1 & Monoterpene synthase 1 & 000149F.g29, EU760348 \\ MTS2 & Monoterpene synthase 2 (myrcene synthase) & 003722F.g32, EU760349 \\ STS1 & Sesquierpene synthase 1 (\(\alpha\)-humulene synthase) & 001011F.g31, EU760350 \\ STS2 & Sesquierpene synthase 2 (germacrene-A synthase) & 001011F.g31, EU760351 \\ TPS9 & Terpene synthase 9 & 001370F.g12 \\ NES & (E)-neralidol/linalool synthase & 004063F.g13 \\ \multicolumn{3}{c}{Transcription regulation of biosynthesis genes} \\ \cline{2-3} MYB3 & Transcription factor HIMYB3 & AM501509 \\ MYB8 & Transcription factor HIMYB8 & 002031F.g25, HG98335 \\ MYB78 & Transcription factor MYB78 & 000063F.g63 \\ bHLH2 & Transcription factor HlIbHLH2 (T178) & 000662F.g4, FR751553 \\ bHLH4 & Transcription factor GLBARA 3 (HlIHL4) & 001145F.g21, HG98336 \\ WRKY1 & WRKY transcription factor 1 & 000029F.g2, CBY88801 \\ TFIIIA & Transcription factor IIIA & 002165F.g6 \\ RPL5 & Ribosomal protein L5 & GAAW01025872 \\ \multicolumn{3}{c}{Reference genes} \\ \cline{2-3} TTG1 & Protein TRANSPARENT TESTA & 002162F.g15, FN689721 \\ MTC2 & Transcription factor MYC2 & 001862F.g5 \\ PIF4 & Transcription factor PIF4 & 000802F.g1 \\ GAPDH & Glyceraldehyde-3-phosphate dehydrogenase & 004935F.g2, 004935F.g5 \\ RH46 & DEAD-box ATP-dependent RNA helicase 46 & 000004F.g75 \\ \hline \end{tabular}  
* HopBase gene number or NCBI GenBank accession number.  
\end{table} 
Table 5: List of analyzed sequences of secondary metabolites biosynthesis genes, transcription factors, and reference genes. Next, relative expressions of four polyphenol and two flavonoid biosynthetic pathway enzyme genes (Table 5) were analyzed. From these genes, the PAL (Figure 3A) gene was only up-regulated by infection in cones of the Premiant (5.7 times) cultivar and the CISH1 (Figure 3C) gene was only up-regulated by infection in cones of the Saaz (2.6 times) cultivar. The OMT1 (Figure 3D) gene, which is an enzyme for last-step xanthohumol biosynthesis, was significantly down-regulated by infection in cones of the Saaz (2.7 times) cultivar. There were no significant differences between healthy and vivoid-infected plants for flavonoid biosynthetic pathway enzyme genes (Figure 4). Figure 2: The relative expression to reference genes (RE = 1) for bitter acids biosynthesis genes (**A**) BCAT1, (**B**) VPS, (**C**) PT1L, (**D**) PT2, (**E**) HS1, and (**F**) HS2 in young cones of HLVd-free and infected plants of hop cultivars. Probability level: *—_p_ < 0.1, **—_p_ < 0.05, and ***—_p_ < 0.01. Note: straight line—median; dashed line—average; and box—95% percentile \(\pm\) standard deviation. The group of hop essential oils includes the wide spectrum of terpenic compounds.