Ethylene is a type of phytohormones with a lot of physiological functions in plants. Ethylene is known to have a role in the seed germination stimulation process, growth and development of plants, blooming, leaf abscission, withered fruits, and fruit ripening. Ethylene hormone emission is constant on young fruits or fruits that haven’t matured yet. However, when fruits are ripe, ethylene gas emission increases so the physiological activity gets faster. The presence of ethylene gas in the atmosphere can also accelerate fruit ripening.
Ethylene hormone emission is affected by several factors: speed of fruit’s physiological activity, mechanical stress put on fruits (touch or friction), chemical stress on fruits, thermal stress, and damage to fruits. Ethylene gas was first identified in 1934 as gas secreted by ripe fruits that make other fruits around it ripe too. After gas chromatography was found, research on ethylene gas advanced greatly.
Ethylene is easy to solve in fat and autocatalytic. Meanwhile, there are four main methods for ethylene bio-synthesizing: linoleic, ethanol, metionin, and beta alanin. Metionin is the most suitable method for fruit ripening process.
Ethylene hormone production is affected by internal and external factors. Internal factors include species, tissue types, development phase, auxin hormone, and cytokinin hormone. Ethylene production happens on certain phases like seed germination, blooming, fruit ripening, fruit and flower withering. The external factors include environmental stress like flood, high temperature, etc, intentional harm done on plants, low oxygen level, and pathogenic attack from parasitical microorganisms.
Ethylene hormone can be non-beneficial to certain fruits and vegetables because they will wither more quickly and will not last long enough in the market. Apples and bananas are famous ethylene gas producers.