Question

The discovery of gibberellins is related with one of the following?
A. Blast disease of rice
B. Rust disease of wheat
C. Bakanae disease of rice
D. Early blight disease of potato

Answer 1

Hint: Various types of diseases are found in plants. Bakanae disease affects the roots of rice plants through roots or crowns. Fungus which causes this disease is Gibberella fujikuroi. Plant hormone gibberellin derived from this pathogen. Rice blast disease is caused by Magnaporthe grisea. Brown rust occurs in wheat which affects the leaf of the plant.

Complete answer:
Gibberellins introduced the plant pathology field with the studies of bakanae disease. It is also known as foolish seedling disease in rice. It causes a strong elongation of rice stems and leaves. In 1926, Japanese scientist Eiichi Kurosawa identified that foolish seedling disease. It is caused by the fungus named Gibberella fujikuroi. The substances produced by fungus affects the symptoms of foolish seedling disease and later on they named the substance as gibberellin.
Gibberellins are present in cell plastids or double membrane bound organelles which are responsible for food making. Gibberellins are the plant hormones which regulate various developmental processes, including stem elongation, dormancy, flowering, flower development, leaf and fruit senescence.
Blast disease of rice affects the leaves of the plant. It causes diamond shaped white to gray or reddish brown lesions. Its fungus pathogen name is Pyricularia oryzae. High nitrogen fertilization, prolonged leaf wetness, and night temperatures favored this rice blast disease.
Rust disease of wheat is caused by the fungus Puccinia triticina. It occurs on the leaf of cereal crops such as wheat, barley, etc. It attacks the foliage of the leaf.
Early blight disease of potato is caused by the pathogen that is Fungus Alternaria solani. It affects the leaves, stems and tubers and can reduce the yield of the crop.
From the above information, we have found that discovery of gibberellins is related with Bakanae disease of rice.

Therefore, the correct answer is option C.

Note: Gibberellins can be of different types. More than 70 gibberellins have been isolated till now. Some of these are GA1,GA2, GA3 and so on. These hormones play a very important role in breaking the dormancy of the seed and promote germination. Gibberellins in the seed believed to signal the starch hydrolysis with the help of enzyme α-amylase. Gibberellins which possess hydroxyl groups are the most biologically active compounds.