The double bop1 bop2 is specifically affected in the resistance induced by MeJA. (a) Length of primary root. bop1 bop2 and their controls were grown in plates with Johnson's Media  with or without 50 μM MeJA. At the age of 10 days, the lengths of the roots were measured in both conditions and their ratio (MeJA treated divided by mock treated) expressed as percentage. Means with the same letter are not significantly different (Fisher's LSD test, P<0.05). (b) Senescence induced by MeJA. The indicated genotypes were grown in soil and mature leaves from 6-week-old plants were cut and floated on water with or without 100 μM MeJA. The amount of chlorophyll (in μg/g fresh weight) was measured after four days of darkness, with three groups of leaves of c. 1 g each. (c) Coronatine as a virulence factor. Bacteria with coronatine (Pto, COR+) or without coronatine (Pto(cfa–), COR-) were inoculated and their growth measured as in Figure 1. (d) Resistance induced by ethylene. The plants were treated with 1 mM 1-aminocyclopropane-1-carboxylic acid (ACC) or a mock treatment, and then Pto was inoculated and measured as in Figure 1. etr1 is a negative control of resistance induced by ethylene. One asterisk means a significant difference with P<0.05, and two asterisks means P<0.01 (Student’s test of one tail).