Growth of plant materials
Nicotiana benthamiana was germinated from seed in 2 l pots of potting media consisting of 70% peat moss, 21% perlite, and 9% vermiculite (Suremix; Michigan Grower Products Inc., Galesburg, MI, USA) in a greenhouse from June-August. This greenhouse is located at 42°43′N, 84°28′W, East Lansing, Michigan, USA. Typical daylight PAR levels inside the greenhouse were between 300-700 µmol m-2s-1, and the temperature was controlled to 27°C during the day and allowed to fall to as low as 18°C at night, though nighttime temperatures typically did not reach this low. Plants were watered with half-strength Hoagland’s solution (Hoagland & Arnon 1938) as needed as juveniles and then daily as adults. Plants were used for experiments from 6-7 weeks of age.