Floral Phenotypes of N. attenuata Wild-Type and Transgenic Plants Impaired in Different Steps of the JA Signaling Cascade.
(A) Simplified model of the JA pathway with emphasis on the sites of transgenic modifications used in this work. Silencing AOC (ir-aoc) interrupts JA biosynthesis at an early step before the formation of OPDA; ectopically expressing Arabidopsis JMT and simultaneously silencing MJE redirects JA toward inactive MeJA and abolishes the conjugation of JA to isoleucine; silencing COI1 interrupts JA-Ile perception through the F-box protein COI1.
(B) The top row shows complete flowers of the wild type, ir-aoc, JMT/mje, ir-coi1, and a cross between JMT/mje and ir-coi1 (JMT/mje × ir-coi1) at anthesis. Corresponding gynoecia (stigma, style, and nectary plus ovary) and stamens (filament with anther) are shown in the middle row, while the bottom row shows dissected nectaries at the base of the ovary. Each row of images was taken with the same magnification. Bars = 5 mm for corollas and gynoecia/filaments and 1 mm for nectaries/ovaries.
[See online article for color version of this figure.]