Developmental phenotype and silencing degree of anp triple mutants. A and B, Ten-day-old triple mutant amiR1 (line 2.5) and amiR3 (line 5.3) seedlings, germinated and grown in the absence (DMSO control) or in the presence of β-estradiol at the indicated concentrations. C, Two-week-old adult plants sprayed with 5 µm (amiR1) and 50 nm β-estradiol (amiR3) every 3 d for three times and grown further for 2 weeks. D and E, Levels of ANP1 (D) and ANP3 (E) transcripts, relative to UBQ5 transcripts, in 10-d-old amiR1 (D) and amiR3 (E) seedlings grown in the absence (–; DMSO control) or in the presence (+) of β-estradiol. Asterisks indicate statistically significant differences between DMSO-treated and β-estradiol-treated seedlings according to Student’s t test (**P < 0.01). Bars = 1 cm.