## 3 Results
### Volatile Profile Alteration after Infestation with Diaphorina citri  
We found that the month-long infestation with \(D\). _citri_ had a pronounced effect on the stored leaf VOC profiles of Sugar Belle leaves on all of the three rootstocks. Student's \(t\)-tests between the control and the infested samples for the individual compounds resulted in significantly different \(p\)-values (\(p<0.05\)) for the majority of the VOCs, which varied by rootstock (Table 2). Figure 2: Two-way hierarchical cluster analysis and heat map of VOC concentrations hexane-extracted from the leaves of control and _Diaphorina citri_-infested Sugar Belle trees on three rootstocks (US-897, C-35 trifoliate, and sour orange). The clusters 1–5 represent groups of compounds with a similar response to the infestation for each rootstock. The rows represent the compounds while the columns represent the treatments (control or infested). The cells are the mean concentration (\(\mu\)g\(\cdot\)g\({}^{-1}\)) of each compound (\(n\) ranges from 6 to 12). \begin{table}
\begin{tabular}{l l l l l l l l l l l l l l l l l l l} \multicolumn{1}{c}{**Cmpd**} & \multicolumn{4}{c}{**SB/SUS-97**} & \multicolumn{4}{c}{**SB/UC-35**} & \multicolumn{4}{c}{**Fold**} & \multicolumn{4}{c}{**Fold**} & \multicolumn{4}{c}{**Fold**} \\ \multicolumn{1}{c}{**No. **} & \multicolumn{1}{c}{**LRI**} & \multicolumn{1}{c}{**Leaf VOC**} & \multicolumn{1}{c}{**Control**} & \multicolumn{1}{c}{**AC-Infested \(p\) Value**} & \multicolumn{1}{c}{**Change**} & \multicolumn{1}{c}{**Control**} & \multicolumn{1}{c}{**ACF-Infested \(p\) Value**} & \multicolumn{1}{c}{**Change**} & \multicolumn{1}{c}{**Control**} & \multicolumn{1}{c}{**ACF-Infested \(p\) Value**} & \multicolumn{1}{c}{**Change**} & \multicolumn{1}{c}{**Control**} & \multicolumn{1}{c}{**ACF-Infested \(p\) Value**} & \multicolumn{1}{c}{**Fold**} \\ \hline
**1** & 900 & \(a\)-Thurgena\({}^{*}\) & 22.03 \(\pm\) 7.06 & 23.80 \(\pm\) 6.08 & 0.566 & 1.08 & 25.98 \(\pm\) 2.84 & 20.62 \(\pm\) 1.62 & **0.002** & -1.26 & 21.03 \(\pm\) 5.44 & 18.40 \(\pm\) 3.52 & 0.173 & -1.14 \\
**2** & 900 & \(a\)-Prunea\({}^{*}\) & 29.46 \(\pm\) 4.94 & 49.77 \(\pm\) 1.27 & **0.001** & 1.69 & 4.01 \(\pm\) 4.01 & 43.06 \(\pm\) 3.29 & **0.000** & 1.39 & 34.30 \(\pm\) 2.32 & 32.94 \(\pm\) 4.25 & 0.244 & 1.15 \\
**3** & 942 & \(a\)-Shurgena\({}^{*}\) & 28.28 \(\pm\) 0.87 & 4.58 \(\pm\) 1.13 & **0.002** & 1.59 \(\pm\) 0.48 & 4.06 \(\pm\) 0.02 & **0.001** & 1.37 & 3.25 \(\pm\) 1.09 & 3.82 \(\pm\) 6.07 & 0.139 & 1.17 \\
**4** & 966 & \(f\)-Prunea\({}^{*}\) & 26.25 \(\pm\) 8.25 & 4.54 \(\pm\) 11.42 & **0.001** & 1.73 & 2.65 \(\pm\) 3.64 & 3.93 \(\pm\) 2.77 & **0.000** & 1.48 & 23.85 \(\pm\) 1.46 & 34.92 \(\pm\) 6.66 & **0.025** & 1.46 \\
**5** & 985 & \(g\)-Prunea\({}^{*}\) & 89.81 \(\pm\) 2.09 & 12.84 \(\pm\) 3.21 & **0.11** & 1.44 \(\pm\) 9.25 & 2.15 \(\pm\) 11.82 & 0.000** & 1.28 & 5.96 \(\pm\) 3.00 & 10.11 & 2.02 & 6.00 & 1.06 \\
**6** & 1018 & \(a\)-Prunea\({}^{*}\) & 1.87 \(\pm\) 1.24 & 4.46 \(\pm\) 2.24 & **0.001** & 2.49 \(\pm\) 3.05 & 5.16 \(\pm\) 0.75 & **0.000** & 2.24 & 2.59 \(\pm\) 1.64 & 4.37 \(\pm\) 1.18 & **0.000** & 1.69 \\
**7** & 102 & \(c\)-Prunea\({}^{*}\) & 33.87 \(\pm\) 8.63 & 61.39 \(\pm\) 10.00 & 1.72 & 3.48 \(\pm\) 4.73 & 51.83 \(\pm\) 6.03 & **0.000** & 1.49 & 3.48 \(\pm\) 3.08 & 4.50 \(\pm\) 9.73 & 0.166 & 1.16 \\
**8** & 1034 & \(\Delta\)-DimFor example, almost all of the monoterpenes increased significantly in US-897 and C-35, but about half did not in SO (Table 2). In the SO and US-897, the majority of the alcohols showed significantly different changes in concentration while only about half in the C-35 showed a significant response. The major alcohol, linalool, was higher in all of the infested samples, but only significantly in US-897 (Table 2). The Sugar Belle leaves from the US-897 rootstock showed the most diverse responses to the infestation with _D. citri._ A total of 16 VOCs decreased (12 significantly, \(t\)-test \(p<0.05\)), while 29 increased (20 significantly) (Table 2).