Validation of expression of selected NnTPS genes in various tissues and in rhizome upon exogenous stimuli. Tissues including leaf, petiole, and rhizome were sampled from 2 month old lotus seedlings. Meanwhile, lotus seedlings were treated with submergence stress or copper stress for 24 h and then rhizome was sampled. The sample without 5 mm copper treatment or submergence treatment was the control (Con). Gene expression was analyzed by real-time RT-PCR. The relative transcript abundance was normalized using lotus actin gene. Values are means ± SE of at least four independent experiments. Bars with different letters are significantly different at P < 0.05 according to Turkey's multiple range test. Fold changes of genes under copper stress and submergence treatment were values relative to control samples. Asterisks indicate significant differences compared with control sample at P < 0.05 levels according to t-test.