Fig. 1.

Silencing of the T. thalictroides AGAMOUS ortholog ThtAG1 results in homeotic conversions of floral organs that phenocopy the ‘Double White’ cultivar. Morphology and development of T. thalictroides wild-type, ‘Double White’ and TRV2-ThtAG1 flowers. (A) Wild-type flower with petaloid sepals (se), stamens (st), and carpels (ca). (B) ‘Double White’ flower with petaloid sepals throughout. (C) Fully silenced TRV2-ThtAG1 flower showing complete homeotic conversion of reproductive organs to sterile organs. (D) Partially silenced TRV2-TtAG1 flower showing incomplete homeotic conversion of reproductive organs. (E–H) Dissected organs, outer to inner (Left to Right). (E) Wild-type sepal, stamen, and carpel. (F) ‘Double White’ outer, middle, and inner sepaloid organs. (G) Fully silenced TRV2-ThtAG1 outer, middle, and inner sepaloid organs. (H) Partially silenced TRV2-ThtAG1 outer sepal, middle sepaloid stamens, and inner sepaloid carpel. (I–L) SEM of developing flowers. (I) Wild-type bud with sepal, stamen, and carpel primordia. (J) ‘Double White’ bud with sepal primordia. (K) TRV2-ThtAG1 bud with sepal primordia. (L) TRV2-ThtAG1 open flower with homeotic organs. (M–Y) Adaxial epidermis cellular types by SEM. (M–O) Wild-type sepal (M), stamen filament (N), and carpel (O). (P–S) ‘Double White’ outer sepal (P), blade of middle homeotic organ (Q), stalk of middle homeotic organ (R), and ventral organ (S). (T–W) TRV2-ThtAG1 outer sepal (T), blade of middle homeotic organ (U), stalk of middle homeotic organ (V), and central homeotic organ (W). (X) Mixed cell types in partially homeotic middle organ depicted in H. (Y) Mixed cell types in stalk of middle organ in H. (Z) Central partially homeotic organ. (Scale bars: 1 cm in A–D; 1 mm in E–H; 100 μm in I–L and Z; and 10 μm in M–Y.)