describe the role of cytokinins and auxins in tobacco cell callus cultures ans apical dominance

Answer 1

Cytokinins and auxins play important roles in tobacco cell callus cultures and apical dominance.

In tobacco cell callus cultures, cytokinins are primarily responsible for promoting cell division and proliferation. They stimulate the production of new cells and play a crucial role in the formation of callus tissue. Cytokinins promote the growth and differentiation of undifferentiated cells, leading to the development of a mass of cells, known as callus, which can be further utilized for tissue culture techniques such as regeneration, somatic embryogenesis, or genetic transformation.

Auxins, on the other hand, are important in promoting cell elongation, root development, and cell differentiation in tobacco cell callus cultures. They are involved in initiating the formation of roots from the callus tissue and are commonly used to induce the differentiation of undifferentiated cells into various specialized cell types, such as roots, shoots, or embryos.

Regarding apical dominance, auxins and cytokinins also play crucial roles. Apical dominance refers to the phenomenon where the terminal bud at the top of a plant suppresses the growth of lateral buds. The control of apical dominance is largely regulated by the balance between auxins and cytokinins. Auxins produced in the terminal bud inhibit the growth of lateral buds by suppressing the production of cytokinins. This results in the dominance of the terminal bud and the suppression of lateral branching. However, if the terminal bud is removed or damaged, the supply of auxins is hindered, allowing the lateral buds to grow and branch out.

In summary, cytokinins are important in stimulating cell division and proliferation in tobacco cell callus cultures, while auxins promote cell elongation, differentiation, and root development. In terms of apical dominance, auxins and cytokinins regulate the balance between the terminal bud and lateral buds, with auxins suppressing lateral growth and cytokinins promoting it.