## 4 Empirical Strategies for Improving TIA Production
### Empirical Optimization of the Culture Medium and Culture Conditions
\begin{table}
\begin{tabular}{l l l l l} \hline \hline
**Material** & **Strategy** & **Total TIAs** & **Observations** & **Refs** \\ \hline \multirow{3}{*}{Suspension cultured cells} & Elicitation with & 1.33-fold & \multirow{3}{*}{2-fold increase} & \multirow{3}{*}{2-fold increase in tabersonine (3.8 mg/g DW)} & [79] \\  & MeJA & (101.9 mJ) & (2.2 mg/g DW) & \\ \hline \multirow{3}{*}{Suspension cultured cells} & Elicitation with & \multirow{3}{*}{ND} & 27.44-fold increase in ajmalicine (137.2 & \multirow{3}{*}{[80]} \\  & MeJA & & 11.12-fold increase in catharanthine & \\  & (100 mJ) & & (55.6 mg/L) & \\ \hline \multirow{6}{*}{Hairy root culture} & Elicitation with & \multirow{3}{*}{1.32-fold increase} & \multirow{3}{*}{2.9-fold increase in serpentine (1.71 mg/g DW)} & \multirow{3}{*}{[81]} \\  & MeJA (250 mJ) & & (49 mg/L) & \\ \cline{1-1}  & & & 3-fold increase in ajmalicine (12 mg/g DW) & \\ \cline{1-1}  & & & 3-fold increase in ajmalicine (12 mg/g DW) & \\ \cline{1-1}  & & & 3-fold increase in catharanthine & \\ \cline{1-1}  & & & (4.34 mg/g DW) & \\ \hline \multirow{3}{*}{Suspension cultured cells} & Elicitation with & \multirow{3}{*}{ND} & 7.9-fold increase in ajmalicine & \multirow{3}{*}{[82]} \\  & _Trichoderma viride_ & & (0.166 mg/g DW) & \\ \hline \multirow{3}{*}{Suspension cultured cells} & Elicitation with the & \multirow{3}{*}{ND} & \multirow{3}{*}{4-fold increase in catharanthine (20 mg/L)} & \multirow{3}{*}{[83]} \\  & protein of & & & \\ \cline{1-1}  & _Phyophthora_ & & & \\ \cline{1-1}  & _boehmeriae_ (BP90) & & & \\ \hline \multirow{3}{*}{Suspension cultured cells} & Elicitation with CDs & ND & 40-fold increase in ajmalicine (200 mg/L) & \\ \cline{1-1}  & _Trichoderma viride_ & & 17-fold increase in catharanthine (85 mg/L) & \\ \hline \multirow{3}{*}{Suspension cultured cells} & Elicitation with & \multirow{3}{*}{ND} & 3-fold increase in catharanthine & \multirow{3}{*}{[84]} \\  & UV-B light & & (0.12 mg/g DW) & \\ \cline{1-1}  & UV-B light & & 117.6-fold increase in vinodine & \\ \cline{1-1}  & & & (0.06 mg/g DW) & \\ \hline \multirow{3}{*}{Suspension cultured cells} & Elicitation with & \multirow{3}{*}{ND} & 18-fold increase in ajmalicine (90 mg/L) & \multirow{3}{*}{[73]} \\  & UV-C light & & 10-fold increase in catharanthine (50 mg/L) & \\ \hline \multirow{3}{*}{Plant} & Elicitation with & \multirow{3}{*}{ND} & 1.5-fold increase in vinistine (2 \(\mu\)g/g DW) & \multirow{3}{*}{[35]} \\  & chromium & ND & 2.16-fold increase in vinblastine & \\ \cline{1-1}  & (50 mJ) & & (2.25 mJ/g DW) & \\ \hline \multirow{3}{*}{Suspension cultured cells} & Elicitation with & \multirow{3}{*}{3.84-fold increase} & \multirow{3}{*}{21-fold increase in ajmalicine (63 mg/L)} & \multirow{3}{*}{[85]} \\  & mycelium and & increase & 17-fold increase in catharanthine (17 mg/L) & \\ \cline{1-1}  & tetramethyl & (96 mg/L) & & \\ \cline{1-1}  & ammonium bromide & & & \\ \hline \multirow{3}{*}{Suspension cultured cells} & Elicitation with & \multirow{3}{*}{3.28-fold increase} & \multirow{3}{*}{13.6-fold increase in ajmalicine (41 mg/L)} & \multirow{3}{*}{[79]} \\  & malate and sodium & increase & 26-fold increase in catharanthine (26 mg/L) & \\ \cline{1-1}  & alginate & (82 mg/L) & & \\ \hline \multirow{3}{*}{Suspension cultured cells} & Elicitation with & \multirow{3}{*}{ND} & 90-fold increase in ajmalicine (450 mg/L) & \\ \cline{1-1}  & MeJA and CDs & & 31-fold increase in catharanthine (155 mg/L) & \\ \hline \multirow{3}{*}{Suspension cultured cells} & Elicitation with & \multirow{3}{*}{ND} & 2.3-fold increase in ajmalicine (1040 mg/L) & \multirow{3}{*}{[85]} \\  & MeJA, CDs and & & (85 mg/g DW) & \\ \cline{1-1}  & UV-C light & & 1.26-fold increase in catharanthine & \\ \cline{1-1}  & & & (196 mg/L) (10 mg/g DW) & \\ \hline \multirow{3}{*}{Suspension cultured cells} & Overexpression of & \multirow{3}{*}{24.6 fold in \multirow{3}{*}{(123 mg/L)}} & \multirow{3}{*}{–} & \multirow{3}{*}{[86]} \\  & _STR_ & & (123 mg/L) & \\ \hline \multirow{3}{*}{Suspension cultured cells} & Overexpression of \multirow{3}{*}{_TDC_ and feeding with loganin and secologanin} & \multirow{3}{*}{125 fold in \multirow{3}{*}{(625 mg/L)}} & \multirow{3}{*}{–} & \multirow{3}{*}{[87]} \\  & _TDC_ and feeding & & & \\ \cline{1-1}  & with loganin and secologanin & & & \\ \hline \hline \end{tabular}
\end{table}