Question

Who discovered cytokinins?

Answer 1

Cytokinins are a class of plant growth regulators that play a role in cell division in the roots and shoots of plants. This hormone aids in cell proliferation, development, and differentiation, as well as apical dominance and the postponement of leaf senescence.
All complex plants, bacteria, mosses, and fungi contain these hormones. Synthetic and natural cytokinins come in a variety of forms, with the majority of them being produced in the root meristem. It's the term for a type of plant tissue that actively encourages cell division. A meristem is a part of the plant that grows at the top of the stem.

Complete answer:
Cytokinins were discovered in $1955$ by F. Skoog, C. Miller, and colleagues. Kinetin is a protein that stimulates cytokinesis. It's an adenine derivative that was extracted from herring sperm DNA that had been autoclaved. Kinetin is not found in plants naturally. This led to the discovery of Zeatin, a cytokinin-like protein isolated from coconut milk and corn kernels. A large number of naturally occurring cytokinins have been discovered. Cytokinins are produced in areas where cells divide quickly.
Efforts to uncover substances that might drive plant cell division led to the discovery of cytokinins. J. Wiesner proposed the existence of growth factors that control plant cell division, as well as the existence of hypothesised chemicals that promote cell division. At the University of Wisconsin, Folke Skoog and colleagues researched the nutritional needs for the growth of plant tissue culture. They found that certain cell division factors were active in vascular tissue. Following that, the Wisconsin researchers looked into numerous cell-derived substances as potential sources of cell division factors. Skoog, Miller, and coworkers isolated and identified kinetin, a highly active cell division factor, from autoclaved herring sperm DNA in $1955$ as a result of these experiments.

Note:
Functions of cytokinins- Cytokinins promote cell division by maintaining protein synthesis, which is necessary for mitosis. The term Mitosis refers to a non-sexual cell division that happens in all living things in order to create more cells for body expansion. Every day, mitosis occurs, replacing damaged cells and allowing them to develop.
Uses-
Plant cell division and development are aided by this substance.
Farmers use it to boost the yield of their crops.
By promoting resistance to some disease-causing bacteria, it plays a key role in plant pathogenesis.