Question

Which of the following tests will you perform to demonstrate the presence of gibberellin?
A. Bolting of cabbage
B. Differentiation in shoots into tobacco callus structure
C. Rapid division in carrot cells
D. Elongation of Avena coleoptile

Answer 1

Gibberellins (GAs) are phytohormone that regulate various developmental processes, which includes stem elongation, germination, dormancy, flowering, flower development, leaf, and fruit senescence. Gibberellin is one of the longest-known classes of phytohormone.

Complete answer:
GAs are a group of tetracyclic diterpene carboxylic acids. Among various different gibberellin identified from plants, a few act as endogenous plant growth regulators (bioactive Gibberellin), but most are in precursors or inactivate forms. The biological functions of GAs have been well shown by the phenotype of mutant type with reduced gibberellin production (GA-deficient mutants) and the effects of chemical inhibitors of gibberellin biosynthesis enzymes on plant growth. The best Gibberellin function in a number of plant species is the promotion of stem elongation. GA plays an essential role in controlling other developmental processes as well. Gibberellin phytohormone induces stem elongation in rosette plants. Cabbage is a rosette plant with profuse leaf growth and retarded internodal length. Before flowering, the internodes elongate enormously. This process is called bolting. Bolting is functional either on long days or on cold nights. When a cabbage head is kept under warm nights, it retains its rosette habit. Bolting can also be induced by artificial methods by applying gibberellins under normal situations.
So, the right answer is Option A (Bolting of cabbage).

Note: It prevents the flowering of short‐day plants in short‐day photoperiods. It induces stem growth in long‐day photoperiods but not in short days because of flowering in cold‐requiring biennial long‐day plants. It prevents or ceases the flowering of short‐day plants in inductive short‐day photoperiods.