IMMUNOLOGY

Detailed explanation-1: -Stimulation in the internode growth just before reproduction is called bolting. If such plants are treated with gibberellins during conditions of rosette growth, the plants bolt, and flower. Normally, bolting is favoured in nature by either cold nights or long days. So the correct answer is ‘gibberellins’.

Detailed explanation-2: -In the case of the rosette plants, there is sudden and excessive internodal growth which is followed by flowering on the application gibberellins is called as bolting. There is increase in the internodal distance which results in the elongation of the stem.

Detailed explanation-3: -In horticulture, bolting is the production of a flowering stem (or stems) on agricultural and horticultural crops before the harvesting of a crop, at a stage when a plant makes a natural attempt to produce seeds and to reproduce.