Figure 2.

Drought stress affects indole-3-acetic acid (IAA) localization in abscission zone (AZ) cells. Immunolocalization of IAA in the floral AZ of yellow lupine exposed to drought-stress (25% WHC, water deficit conditions) (B,E,F) and AZ from control plants growing in the soil of optimal moisture (70% WHC) (A,B). Green fluorescence indicates IAA presence, whereas blue labeling corresponds to nuclei stained with DAPI. AZ area is marked by a white dotted line (A,B). Image (D) presents the magnified control AZ area presented in (A). IAA is found in nuclei (C insert) and cells located near the vascular bundles (VB) (E,F). Bars are given in each image. Endogenous content of IAA in control and drought-treated AZs (G). For all analysis, sections of AZs were collected on the 48th day of cultivation. Data are presented as averages ± SE (n = 3). Significant differences in the stressed plants in comparison to control plants are ^** p < 0.01 (Student’s t-test).