Fig. 9. Phenotypes of ULT antisense (AS) lines. (A) RT-PCR on inflorescences of the least affected ULT AS plants (those showing the flower phenotypes illustrated in G-I). The expression of both ULT1 and ULT2 is downregulated. EF1 was amplified as a control. (B) Vegetative phenotypes of the most severely affected ULT AS lines. The plants were grouped into three classes based on their SAM termination phenotypes (class 1 plants terminate the earliest). Shoot apex bright-field images (first row), SEM images (second row), and longitudinal sections (third row) are shown for 7-day-old wild-type Ler seedlings and 14-day-old ULT AS seedlings. (C-E) Reproductive phenotypes of the ULT AS lines. (C) Six-week-old Ler plants. (D,E) Six-week-old ULT AS plants showing reduced flower number and premature arrest of the axillary inflorescence meristems. (F-I) Flower phenotypes of the least affected ULT AS lines. (F) Ler flower. (G) ULT AS flower with extra sepals and petals. (H) Siliques from a Ler flower and from an ULT AS flower with extra carpels. (I) Silique from an ULT AS flower dissected open to reveal the presence of a fifth whorl carpeloid structure developing inside the fourth whorl (arrow). Scale bars: 20 µm.