Expression of FaJAZ1, FaJAZ8.1 and FaMYC2 under JA treatment
To gain insights into the expression response of F. × ananassa JAZ and MYC genes to JA treatment, we evaluated the expression profiles for FaMYC2, FaJAZ1 and FaJAZ8.1 in MeJA-treated W stage fruit (Fig 8 and S9 Table). We selected FaJAZ1 and FaJAZ8.1 because they showed the highest reduction in expression levels from 21 to 25 DAA (T and R stages) (Fig 7A), when F. × ananassa (cv. Aromas) starts the anthocyanin accumulation (S4 Fig).
10.1371/journal.pone.0197118.g008 Fig 8  Expression of FaJAZ1, FaJAZ8.1 and FaMYC2 under MeJA treatment in Fragaria × ananassa fruit.
Changes in relative expression of FaJAZ1 (A), FaJAZ8.1 (B) and FaMYC2 (C) genes at 15 min, 30 min, 1 h and 6 h under 100 μM MeJA treatment. The expression level of FaGAPDH was used as reference gene to normalize each reaction. The data are from three biological and three technical replicates. Data were subjected to one-way ANOVA test, differences among means ± SE (n = 3) were determined using LSD test. Different letters indicate significant differences between developmental stages (p ≤ 0.05). JAZ, jasmonate ZIM-domain.   FaJAZ1 increased its expression 1.4-fold (p-value ≤ 0.05) respect to control after 30 min of 100 μM MeJA application in fruit (Fig 8A and S9 Table). FaJAZ8.1 showed an upregulation of 2.7-fold (p-value ≤ 0.05) at 6 h after MeJA treatment with respect to a control (Fig 8B and S9 Table). On the other hand, FaMYC2 exhibited a significant upregulation of 1.8, 2.8 and 2.2-fold (p-value ≤ 0.05) at 15 min, 30 min and 6 h after MeJA treatment, respectively (Fig 8C and S9 Table). These results demonstrate that FaJAZ1, FaJAZ8.1 and FaMYC2 are JA-responsive genes in F. × ananassa fruit. Moreover, FaMYC2 responds earlier than FaJAZ1 and FaJAZ8.1 (Fig 8).