2.1 Maintenance of transgenic rice cell cultures
Transgenic rice cell line “9-2”, one of the most stable and productive rrBChE lines, generated as previously described (Corbin et al., 2016), has been shown to be stable including expression of rrBChE for more than 4 years (with continuous subculturing on semi-solid media over that time period). The transgenic rice suspension cultures were grown in shake flasks containing NB+S media, which consists of N6 macronutrients (Chu et al., 1975), B5 micronutrients and vitamins (Gamborg et al., 1968), 30 g/L sucrose, and other components as described elsewhere (Macharoen et al., 2020). The shake flasks were maintained in an orbital shaker at 140 rpm and 27˚C in the dark and subcultured every 7-8 days.