- A A specialized auxin derivative synthesized directly within the shoot apical meristem region
- B FT protein (Flowering Locus T) produced in leaves, transported to shoot apex via phloem
- C Gibberellin A3 synthesized locally within developing floral primordia tissue
- D A cytokinin variant transported acropetally upward from the root system below
Correct answer: B. FT protein (Flowering Locus T) produced in leaves, transported to shoot apex via phloem
Explanation: Florigen = FT (Flowering Locus T) protein. Produced in leaf phloem companion cells under inductive photoperiods, transported to shoot apical meristem where it activates flowering genes.
Concept context
Phases of plant growth, the five classical plant hormones plus newer ones, photoperiodism, vernalization, and seed dormancy.