Patterning of the individual flower primordia in transgenic GhLFY and GhUFO
RNAi lines. A and B, Transgenic GhLFY
RNAi (A) and GhUFO
RNAi (B) plants with severe phenotypes form primary primordia (P1; shaded in yellow) that repeatedly initiate secondary (P2) and tertiary (P3) primordia (shaded in orange) in all flower types (ray, trans, and disc). C and D, Patterning of flower primordia in GhLFY
RNAi (C) and GhUFO
RNAi (D) transgenic plants with milder phenotypes shows flower type-specific responses. In both lines, the ray flower primordia uniformly initiate secondary primordia and, consequently, secondary flowers. The response in trans and disc flowers shows opposite effects: in GhLFY
RNAi lines, the disc primordia, and in GhUFO
RNAi lines, the trans primordia, pattern as normal flowers (shaded in red). Bars = 100 µm. E, Heat map of quantitative RT-PCR results shows expression profiles of the B, C, and E function MADS box genes in developing primary (R1, T1, and D1) and secondary (R2, T2, and D2) primordia in different flower types. D, Disc flower primordia; M, mild phenotype; R, ray flower primordia; S, severe phenotype; T, trans flower primordia; WT, wild type.