Plant Material
Tobacco seedlings were transplanied into 5-inch soil pots in the greenhouse.Plants were allowed to grow for 4 to 5 weeks after transplanting and then covered with black cloth 2 days before the leaves were harvested.
All other plants were grown in vermiculite under low light intensity and leaves or cotyledons were harvested from 5 to 10 day old seedlngs without transplantation.(https://www.daowen.com)