FIGURE 8.

Effect of overexpression of GmeIFiso4G-1a on Arabidopsis plants exposed to dehydration or low temperature stress. Arabidopsis WT or transgenic GmeIFiso4G-1a overexpressing lines (OE-5 and OE-8), grown in non-sterile conditions, were analyzed in the presence (+β), or absence of β-estradiol treatment after dehydration or cold stress. (A) Arabidopsis seedlings were irrigated during 10 days with half strength MS medium. For dehydration stressed samples (DH), irrigation was interrupted almost completely, with the exception of the everyday addition of 200 μL of 5 μM β-estradiol or the same volume of water for non-treated samples. Control (well-watered) plants were treated (+β), or untreated with β-estradiol. Pictures were taken 9 days after the onset of stress. (B) Free proline content in well-watered controls (Ctrl) or 9 days dehydration stressed (DH) in the presence or absence of β-estradiol treatment. (C) Ten days old Arabidopsis plants were exposed to low temperature (4°C) for 2 weeks and photographed. Controls (plants grown at 22°C) and cold stressed plants (LT), treated with of 5 μM β-estradiol (+β), or untreated, were photographed 2 weeks after the onset of stress. (D) Anthocyanin content was determined in plants growing at 22°C (Ctrl) or exposed for 2 weeks to 4°C (LT), in the presence (+β) or absence of β-estradiol. Asterisk (^∗) indicates significant differences between the wild type and the transgenic lines at p < 0.05 confidence level.