2.1 Plant materials and growth conditions
The Honghua Dajinyua cultivar (N. tabacum ) kept by our lab was
used for transgenic manipulation, gene expression analysis, and
detection of flavonoids content in the present study. Tobacco seeds were
soaked and sterilized as described previously
(Z. Wang et al., 2018;
Z. Wang et al., 2020), and then
germinated on MS medium. The sterile seedlings were either used for
transgenic manipulation, or transplanted into pots for normal growth
(28°C/16h light, 23°C/8h darkness) until the flowering stage. Various
tissues were collected from the plants for RNA extraction or flavonoids
content detection.