Topping-induced expression of endogenous nta-eTMX27 in tobacco root. A, The predicted base-pairing pattern between nta-miRX27 and its eTM nta-eTMX27. B. Semiquantitative RT-PCR analysis of expressions of nta-eTMX27 in four tissues. Tobacco glyceraldehyde 3-phosphate dehydrogenase gene (NtGAPDH) was used as control. RT– represents RT negative control, i.e. RT without reverse transcriptase. C, The relative transcription levels of nta-eTMX27, QPT2, and nta-miRX27 in tobacco root tissues measured at 3, 6, 12, 24, and 48 h after topping. Three independent experiments, each consisting of three control and topping-treated plants, were carried out for quantification analyses, and representative results in one time are presented. The expression level at the 0-h time point (control) was arbitrarily set as 1. Error bars indicate the sd.