Ethylene: Chemical nature, Biosynthesis, Bioassay, Physiological effects and Mode of action
Ethylene (C2H4):- > It is the only gaseous hormone. > It is found in ripening fruits. 1. Discovery of Ethylene:- - Sarah Doubt (1917) discovered that ethylene stimulated abscission. - Gane (1934) established that ethylene was natural product of ripening fruits and possibly stimulated fruit ripening. - Crocker and Knight (1908, 1913) identified ethylene as the active constituent of both, illuminating gas and tobacco smoke. - With the discovery of gas chromatography, it became possible to estimate ethylene levels and soon after in 1969 ethylene came to be accepted as a plant hormone. 2. Chemical nature of Ethylene:- Ethylene is a hydrocarbon. As the name suggests it has four atoms of hydrogen and two atoms of carbon connected with a double bond. 3. Biosynthesis of Ethylene:- Ethylene is known to be synthesized in plant tissues from the amino acid methionine. A non-protein amino acid, 1-amino cyclopropane-l-carboxylic acid (ACC) is an important intermediate a...