Phenotypic Analysis of Transgenic Plants

The in vitro behavior of the transgenic AtNPR1 lines was evaluated. For this purpose, 20 shoot segments, 1.5–2 cm in length, with two nodes and deprived of the shoot apex, were isolated from each transgenic line and cultured in RP medium supplemented with 2 mg/L zeatin riboside (Vidoy-Mercado et al., 2012). After 8 weeks, the number of axillary shoots and their lengths were quantified over three subcultures. To evaluate rooting capacity, 2-cm-long apical shoots with at least one node were used. Rooting conditions were as previously described (see section “Binary Vector and Olive Transformation”). After 9 weeks, the number of roots and the length of the main root were measured. The non-transgenic line P1 was used as a control, and the experiment was carried out in triplicate.

Rooted plants were acclimatized to ex vitro conditions as previously indicated (see section “Binary Vector and Olive Transformation”). After 9 months of growth in the confined greenhouse under natural daylight conditions, the plant height and the diameter of the main stem were measured. Fourteen plants per transgenic and control line were evaluated.