Figure 1.

HT induces NtPMT1 accumulation and nicotine biosynthesis. Data are the mean ± SD from triplicate experiments. Bars with different letters are significantly difference at p < 0.05 (Tukey's test). (A) The effects of different treatments on alkaloid content in the roots of tobacco seedlings. Four-week-old tobacco seedlings were exposed to leaf wounding (W), HT at 32°C, salinity (S) at 100 mM NaCl, or heavy metal (HM) at 30 μM CdCl₂ for 3 days or under normal condition at 24°C as the control (CK), and the contents of the indicated alkaloids were measured. (B) Time course showing the effect of HT on the induction of nicotine biosynthesis in the roots of tobacco seedlings. The 4-week-old seedlings were grown at 32°C for the indicated periods of time, and the nicotine content was measured. (C) HT induces NtPMT1 accumulation. Four-week-old seedlings were grown at 32°C for the indicated time, and the root tissue was used for the analysis. NtPMT1 accumulation was monitored by immunoblotting using anti-NtPMT1. Anti-Actin was used as a loading control.