## 3 Results
### Transcriptome and Metabolome Data Validation  
We employed qRT-PCR to verify the expression of key genes involved in floral synthesis, including _TPS_, _HMGS_, _HMGR_, _MVD_, _AACT_, _IDI_, _GGPS_, _PMK_, and _FDPS_. The expression levels of these candidate genes were examined in petals during the four growth and development stages of YJ and NW. The relative expression values obtained through qRT-PCR were highly consistent with the trends observed in the RNA-seq data, affirming the accuracy of the transcriptome data for further research (Figure 10).  
Changes in Relative Content of Major Volatile Compounds following Transient Overexpression and Gene Silencing of R&TDS  
In the _RfFDPS_ RNAi line, the expression level of _RfFDPS_ was 0.38 times lower than that of the _pTRV2_ control line. Except for the increased expression levels of _GGPS_ and _TPS_, the expression levels of all other screened DEGs were decreased, ranging from 0.35 to 0.92 times that of the control line (Figure 11A). Additionally, an analysis of volatile compounds from the _RfFDPS_ RNAi line revealed that the main volatile components remained largely unchanged, with a rising trend in total monoterpene content, which was 1.80 times higher than that of the control line (Figure 11C). Specifically, the contents of monoterepenes such aslinalool, 1,5,7-ocatrien-3-ol, 3,7-dimethyl-, and 5,9-undecadien-2-one, 6,10-dimethyl-, (E)-increased, while the content of terpinen-4-ol decreased. Specifically, thelinalool content was 1.38 times that of the control line, and the terpinen-4-ol content was 0.14 times that of the control line (Figure 11D). However, the total content of sesquiterpene volatiles was 0.2 times the original (Figure 11F).  
In the _RfFDPS_ OE line, the expression level of _RfFDPS_ was 1.94 times higher than the _pBWA(V)BS1302_-GFP control line. Except for the decreased expression levels of _GGPS_ and _TPS_, the expression levels of all other screened DEGs increased, ranging from 1.03 to 2.08 times that of the control line (Figure 11B). Furthermore, an analysis of the _RfFDPS_ OE line's volatile compounds indicated that the main volatile components remained largely unchanged, but the total monoterpene content showed a downward trend at 0.49 times that of the control line (Figure 11C). The contents of monoterepenes such aslinalool, 1,5,7-ocatrien-3-ol, 3,7-dimethyl-, and 5,9-undecadien-2-one, 6,10-dimethyl-, (E)- decreased, while the content of terpinen-4-ol increased. Among them, thelinalool content was 0.33 times that of the control line, and the terpinen-4-ol content was 1.64 times that of the control line (Figure 11D). However, the total content of sesquiterpene volatiles increased at 1.51 times the original level (Figure 11G and data are listed in Additional Table S4).  
Figure 10: Bar chart displaying the results of qRT-PCR validation for candidate genes. The lines in the chart represent the relative expression levels obtained through qRT-PCR validation results for YJ and NW samples. The transcriptome data for corresponding genes in YJ are depicted in orange, while those for NW are shown in blue. The data presented here represent the average of three replicates, with the error bars indicating the standard error (SE) (n = 3).  
Using Wolfpsort online software (Additional Table S5), _RfFDPS_ was predicted to be present in the cytoplasm. To confirm its protein localization, a strong fluorescence signal was observed in the cytoplasm of the cell via laser confocal microscopy (Figure 11G), confirming that the _RfFDPS_ protein is located in the cytoplasm.